The 8th Japan-Taiwan Conjoint Slide Conference
第八屆台日切片討論會
KYOTO
April 20-21, 2024

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1. General information
Date:

April 20-21, 2024

Venue:

Inamori Hall, Shiran-kaikan, Kyoto University

President: 羽賀博典 Hironori Haga (Kyoto University)

Organizer: 南口早智子 Sachiko Minamiguchi (Kyoto University)

Contact information:
E-mail address: pathology@kuhp.kyoto-u.ac.jp
Mailing address: Department of Diagnostic Pathology, Kyoto University Hospital
54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 Japan
2. Program at a glance
April 20th (Sat) - Kyoto City Tour and Welcome Reception
08:45
09:00-17:30
18:00-20:00

在京都八條都酒店大堂集合/都ホテル京都八条エントランス集合京都觀光歡迎會 (THE THOUSAND KYOTO)

April 21st (Sun) - Slide Conference and Poster Session
08:15

Meet at the entrance of Miyako hotel Kyoto Hachijo(Shuttle bus will take you to the venue)

08:30-09:00

Registration

09:00-09:10

Opening Ceremony

09:10-12:40

Slide conference (Inamori Hall)

10:25-11:05

Poster session (Hall Lobby)

12:40-14:00

Farewell Party (Yamauchi Hall)

3. Registration Fee for Taiwanese Participants
Please paid by Japanese Yen cash.
Participants joining the Kyoto City tour and Welcome Party, please make the payment at
the Welcome Party reception on April 20th. For those not attending, please make thepayment at the reception desk of the slide conference venue on the 21st.
Kyoto City tour

JPY 5,000

Welcome Reception

JPY 5,000

Slide Conference and Farewell Party

JPY 5,000

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4. Access to the Venue
April 20th, 2024
Kyoto City Tour participants should meet at the entrance of the Miyako Hotel at 8:45 a.m.
After the tour, the bus will go directly to The Thousand Kyoto, the venue for the welcome
reception.

April 21st, 2024
A shuttle bus will run from the entrance of Miyako Hotel to Shiran-kaikan, and will leaveat 8:15 a.m. Please make sure to be on time.

Linear bus service (HOOP, https://hoopbus.jp/) is available from Kyoto University to
Kyoto Station Hachijo Exit. Please ask for a bus coupon if you wish to use it.

35. Venue Map
Ground ﬂoor, Shiran-kaikan
Please proceed to the second ﬂoor where staffs will guide you.
Second Floor, Shiran-kaikan
Reception is on the second ﬂoor.

inamoriHall
Slide Conference 9:00-12:40
WOMEN

MEN

Hall Lobby

Poster Session 10:25-11:05

YamauchiHall
Farewell Party 12:40-14:00

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6. Virtual Slide Access
Japan cases (J-1~5)
https://pathology.kuhp.kyoto-u.ac.jp/
Username: jtcsc8
Password: jtcsc8
Taiwan cases (T-1~5)
https://tinyurl.com/jtcsc8
You can log in using any of the usernames provided below. However, please note thatsimultaneous logins with the same username are limited to 5 users. In case you
encounter any errors, kindly try logging in with a different username.
Username:
twiap.guest01@guest.com
twiap.guest02@guest.com
twiap.guest03@guest.com
twiap.guest04@guest.com
twiap.guest05@guest.com
Password:
twiap_19670916
7. Instructions for Case Presenters-

Presentation time: 15 mins for each case (5 mins for discussant, 5 mins for submitter,5 mins discussion)-

Presentation ﬁles should be created using Microsoft PowerPoint for PC. Functionsof those made by Macintosh will not be secured.

8. Instructions for Poster Presenters
A display board giving a display area of approximately 90 cm (width) x 140 cm (height)
will be provided for poster display. Pushpins will be provided to all poster presenters at
the congress. Staff will be available to assist you. Please set up your poster between
08:30 - 08:55. In the poster session, there will be no moderator leading the session. It will
be a free discussion involving posters.

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Slide Conference Timetable
D: Discussant, S: Submitter, M: Moderator
08:30-09:00

Registration

09:00-09:10

Opening Ceremony

羽賀博典 Hironori Haga (Kyoto University)

鄭永銘 Yung-Ming Jeng (National Taiwan University)
09:10-09:25
DS
M

大江知里 Chisato Ohe (Osaka Metropolitan University)

林士堯 Shih-Yao Lin (Taipei Veterans General Hospital)

賴瓊如 Chiung-Ru Lai (Taipei Veterans General Hospital)

09:25-09:40
D
S
M

S

Case 2 (J-1)

胡家發 Chia-Fa Allen Hu (Kaohsiung Chang Gung Memorial Hospital)

間敬邦 Hirokuni Hazama (Kyushu University)

久岡正典 Masanori Hisaoka (University of Occupational and Environmental Health)

09:40-09:55
D

Case 1 (T-1)

Case 3 (T-2)

長峯理子 Michiko Nagamine (National Cancer Center Hospital East)李沛航 Pei-Hang Lee(Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine)M黃玄贏 Hsuan-Ying Huang(Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine)

09:55-10:10
DS
M

黃彥碩 Yen-Shuo Huang (Kaohsiung Medical University Hospital)
塩見達志 Tatsushi Shiomi (Kawasaki Medical School)

湊宏 Hiroshi Minato (Ishikawa Prefectural Central Hospital)

10:10-10:25
D
S
M

Case 4 (J-2)

Case 5 (T-3)

大園一隆 Kazutaka Ozono (Kumamoto University Hospital)許惠婷 Hui-Ting Hsu (China Medical University Hospital)

杭仁釩 Jen-Fan Hang (Taipei Veterans General Hospital)
610:25-11:05

Poster Session & Coffee Break

11:05-11:20

Case 6 (J-3)

DS
M

張中亭 Sabrina Chang (Taipei Veterans General Hospital)
小野佐和子 Sawako Ono (Okayama University)

浦野誠 Makoto Urano (Fujita Health University Bantane Hospital)

11:20-11:35
DS
M

山下大祐 Daisuke Yamashita (Kobe City Medical Center General Hospital)

鄭子謙 Tzu-Chien Cheng (Keelung Chang Gung Memorial Hospital)
王任卿 Ren Ching Wang (China Medical University Hospital)

11:35-11:50
D
S
M

S
M

都築豊徳 Toyonori Tsuzuki (Aichi Medical University)
牛久哲男 Tetsuo Ushiku (University of Tokyo)

S
M

Case 9 (T-5)

合田直樹 Naoki Goda (Kyoto University)

陳琬清 Wan-Ching Chen (Taichung Veterans General hospital)
鄭永銘 Yung-Ming Jeng (National Taiwan University)

12:05-12:20
D

Case 8 (J-4)

張佳平 ChiaPing Chang (Taipei Veterans General Hospital)

11:50-12:05
DCase 7 (T-4)

Case 10 (J-5)

黃中彥 Chung-Yen Huang (National Taiwan University Hospital)

寺本祐記 Yuki Teramoto (Kyoto University Hospital)

松原修 Osamu Matsubara (Hiratsuka Kyosai Hospital)

12:20-12:40

Closing Ceremony

鄭永銘 Yung-Ming Jeng (National Taiwan University)
小田義直 Yoshinao Oda (Kyushu University)

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Case 1 (T-1)
Submitter: 林士堯 Shih-Yao Lin
Institution: Taipei Veterans General Hospital
Case Subspecialty: Gynecology Pathology
Location and Specimen Type: Retroperitoneum, Tumor excision
Short History:
This is a 54-year-old female diagnosed with leiomyosarcoma after myomectomy inanother hospital on 2021/11/1. Staging surgery was suggested at that time, and she
decided to transfer to our hospital. Our gynecologist performed total hysterectomy withbilateral salpingo-oophorectomy and bilateral pelvic lymph node dissection for her on
2021/12/17. Pathological examination revealed quite scant atypical cells in the uterus
and no other involvement. She was free of disease until 2023/6/10 when lower abdomen
MRI revealed a newly developed 7.4 cm retroperitoneal tumor in the cul-de-sac close to
the rectum. She received tumor excision with low anterior resection on 2023/6/21.

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Case 2 (J-1)
Submitter: 間敬邦 Hirokuni Hazama
Institution: Department of Anatomic Pathology, Graduate School of Medical Sciences,
Kyushu University
Case Subspecialty: Bone and soft tissue
Location and Specimen Type: Sacrum, open biopsy and resection
Short History:
74 years old, MaleThe patient with no medical history experienced progressively worsening sacral pain in
the supine position for one year. On physical examination, an elastic-soft mass was
detected at the sacral region. The patient had no bladder and bowel dysfunction. Plain
X-ray-images showed focal osteosclerosis and cortical disruption of the coccyx
suggesting osteolysis on the lateral view. Plain CT-images showed a well-deﬁned mass,
about 11cm in size, with calciﬁcation and contiguous to the sacrococcygeal bone. MRIimages revealed internally heterogeneous low- to equivalent-signal on T1-weighted
images and high-signal on T2-weighted images. PET-CT-images showed no obvious
systemic metastasis. Open biopsy was performed. Histologically, the specimen showeda sheet-like proliferation of atypical cells having clear to eosinophilic cytoplasm,
accompanied by myxoid matrix and hemorrhage. Immunohistochemically, the atypicalcells were positive for brachyury. These features indicated that of conventional
chordoma. After the biopsy, wide resection was performed on the tumor. Grossly, themass was a yellowish-white, well-deﬁned lesion with hemorrhage and necrosis.

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Case 3 (T-2)
Submitter: 李沛航 Pei-Hang Lee, MD
Institution: Department of Anatomical Pathology, Kaohsiung Chang Gung Memorial
Hospital and Chang Gung University College of Medicine
Case Subspecialty: Bone and soft tissue
Location and Specimen Type: Lung, right lower lobe, wedge resection
Short History:
This is a 33-year-old man who, a non-smoker, denied any relevant systematic disease.
During health check-up in August 2023, chest radiography revealed a solitary right lower
lung nodule, which was further demonstrated to be spiculated by chest computed
tomography, raising suspicions of malignancy. Wedge resection was performed in
September 15th, 2023. The specimen submitted consists of a wedge resection of theright lower lung, measuring 4.9 x 4.6 x 1.8 cm and weighing 10.5 gm. The pleural surface
showed focal retraction. On cutting, the ill-deﬁned tumor, measuring 1.3 x 1.2 x 1.1 cm,
was located beneath the pleura, 0.6 cm from the parenchymal resection margin, andgrayish-white and solid in appearance.

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Case 4 (J-2)
Submitter: 塩見達志 Tatsushi Shiomi, Hirotake Nishimura, Takuya Moriya
Institution: Department of Pathology, Kawasaki Medical School
Case Subspecialty: Hematology
Location and Specimen Type: Dura mater
Short History:
A case of foam cells distributed in the dura mater
A 59-year-old Japanese man presented with gait disturbance and dysarthria. His family
history was not signiﬁcant. Magnetic resonance imaging revealed thickening of the duramater in the cerebrum. Laboratory testing showed elevated serum concentrations of sIL2 receptor (2751 U/mL; normal range, 122-496 U/mL), IgG (2014 mg/dL; normal range,
870-1700 mg/dL), and IL-6 (78.1 pg/mL; normal range, 0-8 pg/mL). A biopsy of the duramater revealed distributed foam cells with lymphocytes and plasma cells.
Immunohistochemically, these foam cells were positive for CD68 (PGM1), CD163, andfascin.

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Case 5 (T-3)
Submitter: 許惠婷 Hui-Ting Hsu
Institution: China Medical University Hospital
Case Subspecialty: Head and neck
Location and Specimen Type: Nasal cavity, maxillectomy
Short History:
A 56-year-old woman, with a history of hypertension, presented with intermittent rightnasal bleeding for 8 months. During the nasendoscopy examination, the presence ofblood over the sinus ostium was noted. The head and neck CT scan of the paranasal
sinuses demonstrated a 30x28x25 mm lesion in the right maxillary and ethmoid sinuses,with destruction of right nasal turbinate and right inferior orbital wall, and bulging into
right inferior orbit. Subsequently, a maxillectomy and repair of the orbital ﬂoor were
performed.

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Case 6 (J-3) - A case of parotid gland tumor
Submitter: 小野佐和子 Sawako Ono1, Hidetaka Yamamoto1, Kenji Nishida2
Institution:
1. Department of Pathology and Oncology, Graduate School of Medicine, Dentistry andPharmaceutical Sciences, Okayama University
2. Department of Pathology, Okayama University Hospital
Case Subspeciality: Head and neck
Location and Specimen Type: Parotid gland, parotidectomy
Short History:
54 years, MaleA patient presented with a several-year history of a right parotid mass. Magnetic
resonance imaging (MRI) revealed a 3.5-cm nodular mass in the right parotid gland andWarthin tumor was suspected. The positron emission tomography-computed
tomography (PET-CT) detected no other primary or metastatic lesions. The patientunderwent parotidectomy. Macroscopically, the resected specimen showed a solid welldeﬁned mass with uniform color tone.

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Case 7 (T-4)
Submitter: 鄭子謙

Tzu-Chien Cheng

Institution: Keelung Chang Gung Memorial Hospital
Case Subspecialty: Hematolymphoid
Location and Specimen Type: Posterior aspect of right-sided upper gingiva, andedentulous ridge of maxilla (#15 and #16 area), wide excision including inferior
maxillectomy

Fig. 1 Clinical intraoral finding

Fig. 2 Coronal MRI image, T1WI with
contrast enhanced

Short History:
The 74-year-old man presented with a progressively enlarging ulcer on the right uppergingiva, accompanied with pain for months (Fig. 1). The patient reported no signiﬁcant
past medical history, personal history, or family history. Upon physical examination, an
ulcerative lesion was observed on the posterior aspect of right-sided upper gingiva. No
palpable neck lymphadenopathy was noted.
Laboratory tests revealed mild normocytic anemia (Hb = 11.3 g/dL, HCT = 33.2%, MCV =95.4 fL) and leukopenia (WBC = 3,500 per μL). The platelet count (PLT = 186,000 per μL)
20was normal.
Both CT scan and MRI of the head and neck region demonstrated a tumor measuring up
to 3.4 cm in diameter on the ﬂoor of the right maxillary sinus, with bone destruction (Fig.
2). A subsequent PET scan identiﬁed a tumor in the right-sided upper gingiva (astandardized uptake value (SUV) of 5.7, score 4) and a right-sided paratracheal nodal
lesion (score 2).
A wide excision including inferior maxillectomy and right-sided neck dissection (level I
to level III) were performed. Gross examination of the excised tissue revealed an
inﬁltrative white tumor measuring 2.8 x 2.5 x 2.2 cm, with invasion into the maxilla.
Histologically, all the dissected lymph nodes were free of malignancy.
A panel of immunohistochemical stains was performed. The tumor cells showed patchy
staining with INSM1 and synaptophysin, and were negative for PanCK (AE1/AE3),
CAM5.2, p40, NUT, chromogranin, SOX10, S100, HMB45, CD99, NKX 2.2, desmin, CD45
(LCA), CD3, and CD20, along with intact INI1 and BRG1 nuclear expression.

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Case 8 (J-4) - A case of Unknown Primary Cancer (CUP)
Submitter: 都築豊徳 Toyonori Tsuzuki
Institution: Department of Surgical Pathology, Aichi Medical University, School of
Medicine
Case Subspecialty: Genitourinary Pathology
Location and Specimen Type: Lymph node, excisional biopsy
Short History:
73 years, MaleA patient was referred to the Department of Hematology in our hospital due to left leg
swelling and enlarged lymph nodes in the groin. The patient's blood tests showed that
their CEA level was 6.9 ng/mL (normal range: <5.0ng/mL), PSA level was 5.5 ng/mL(normal range: <5.0ng/mL), and soluble IL-2R level was 899 U/ml (normal range: 121613 U/ml). No hematological disorders were detected. An inguinal lymph node biopsy
was performed, which revealed that the lymph node was effaced by cancerous cells thatwere positive for CK7 and PSA, and negative for CK20, CDX-2, and PAX8. Even though CT,
MRI, and PET/CT scans were performed, no abnormal image ﬁndings were detected. The
patient underwent a prostate needle biopsy, gastroscopy, and colonoscopy three months
later, but no abnormal ﬁndings were found.

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Case 9 (T-5)
Submitter: 陳琬清 Wan-Ching Chen
Institution: Taichung Veterans General hospital.
Case Subspecialty: Head and Neck.
Location and Specimen Type: Nasal, paranasal, and skull base tumors
Short History:
The 72-year-old female patient had no reported medical history. She presented to thehospital this time due to recent issues with her eyes being unable to focus.
Upon examination, only nasal congestion was observed, and serology tests yielded
normal results. An MRI from another hospital revealed a substantial brain tumor (6.5 cm)
over the frontal base with downward extension and nasal cavity invasion. Suspected to
be an atypical meningioma, she was referred to our hospital for further evaluation andsurgical intervention.
During the surgery, a frozen sample was sent for analysis, and the initial impression fromthe surgeon was atypical meningioma. Our initial frozen assessment indicated ameningioma with atypical features. Subsequently, the patient underwent transsphenoidal tumor removal.

MRI: T1 sagittal view

MRI: T2 coronal view24

CT with contrast

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Case 10 (J-5)
Submitter: 寺本祐記 Yuki Teramoto
Institution: Department of Diagnostic Pathology, Kyoto University Hospital
Case Subspecialty: Pulmonary Pathology
Location and Specimen Type: Lung, left upper lobe, lobectomy.
Short History:
The patient was a 70-year-old male with no smoking or family history.
6 years prior to surgery: Prostate biopsy revealed acinar adenocarcinoma with Gleason
score (GS) 3+3, which was followed up.
4 years prior to surgery: Re-biopsy upgraded the prostate cancer to GS 4+4, and thepatient underwent hormone therapy and IMRT. Since then, PSA remained at 0.6~1.1
ng/ml and was considered to be under good local control.

Year of surgery: A 4.4 cm-sized mass was found in the left upper lobe of the lung onchest X-ray, and the patient underwent left upper lobectomy at our hospital. The
pathological diagnosis was initially “colloid adenocarcinoma of the lung”. However, thethoracic surgeon pointed out that the patient had a history of prostate cancer and added
NKX3.1 immunostaining, which was diffusely positive for tumor cells. Therefore, thepathological diagnosis was corrected as "metastatic carcinoma of prostatic origin”.
1 year after surgery: Sudden cognitive decline and disorientation appeared. A CT scanof the head indicated the appearance of multiple brain tumors. Based on the clinicalhistory, it was assumed to be metastasis of prostate cancer. However, because thecourse deviated from the common clinical course of prostate cancer, the urologist asked
the GU pathologist to reexamine the histology of the lung tumor.

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Poster 1 (P-1)
Cardiac pseudomyogenic hemangioendothelioma with a novel
MAPK1IP1L::FOSB fusion: A case report.
張珍 Chen Chang1, Nai-Syuan Chen1, Wan-Shan Li2, Yu-Chien Kao1
1. Department of Pathology, National Cheng Kung University Hospital, College ofMedicine, National Cheng Kung University, Tainan, Taiwan
2. Division of Molecular Pathology, Department of Pathology, Chi Mei Medical Center,
Tainan, Taiwan
Pseudomyogenic hemangioendothelioma (PHE) is a rare, intermediate-grade vasculartumor with histological features mimicking myoid tumors or epithelioid sarcomas.
Predominantly affecting young adults under 40 years of age, PHE often presents as
multiple discontiguous nodules in different tissue planes from cutaneous, subcutanoeus
to intramuscular and intraosseous sites. The most common location is the lower limbs(55%), followed by upper limbs (20%), trunk (20%) and rarely over the head or neck. The
tumor is driven by FOSB overexpression and characterized by FOSB gene rearrangement.
We report a case of a 4-year-old girl who presented with syncope, intermittent pallor,
weakness, and fever. An echocardiogram and CT scan revealed a large heart tumor in
the right atrium (RA) and right ventricle. The patient underwent tumor excision, revealing
a 5.2x2.5cm tumor originating from the RA wall near the atrioventricular groove.
Histopathological examination showed inﬁltrative spindle cell proliferation within a
myxoid stromal background. The tumor cells had mild nuclear irregularity and occasional
elongated eosinophilic cytoplasm, arranged in loose fascicles or haphazardly dispersedin the myxoid stroma. In addition, foci of epithelioid cells with eosinophilic cytoplasm
were also present. Lymphocytic inﬁltration, intratumoral hemorrhage, and many delicate
capillaries were also seen in areas. Immunohistochemically, the tumor cells werepositive for ERG, AE1/AE3, FOSB, focally positive for CD34 and SMA, and negative for
CD31,

S100, ALK (5A4), ROS-1, desmin, myogenin, MDM2, CDK4, Pan-TRK, andcalretinin. Targeted RNA sequencing (Archer FusionPlex Pan-Solid v2 panel) identiﬁed anovel MAPK1IP1L::FOSB fusion, supporting the diagnosis of PHE. In conclusion, thiscase underscores the diagnostic challenges associated with PHE and the need forcomprehensive histopathological and molecular analysis for accurate diagnosis. The
unusual presenting age and location also pose diagnostic diﬃculties.
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Poster 2 (P-2)
Melanotic Xp11 Translocation renal cancer / PEComa: A Case Report陳怡儒 I-JU CHEN
Department of Pathology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
Melanotic Xp11 translocation renal cancer is a rare renal neoplasm, with approximately
20 cases documented in the literature so far. Since this type of tumor exhibits similar
clinical characteristics, morphology and immunoproﬁle with perivascular epithelioid celltumor (PEComa), some studies have considered it as a variant of Xp11 translocation
PEComa.1 Herein, we report a case of a 30-year-old female with right renal tumor. Her
past medical history included focal endometrial hyperplasia without atypia. She
presented to our outpatient department due to incidental ﬁnding of a right renal tumor in
the health exam. Magnetic resonance imaging showed a 5.7 cm mass lesion at rightkidney, with hemorrhagic part, but no obvious fat component. Therefore, a laparoscopic
right radical nephrectomy was performed. Grossly, there was a well-circumscribed andblack tumor, measuring 5.3 x 4.8 x 4.8 cm in size, in the lower pole of the kidney.
Microscopically, it showed a well-demarcated tumor, arranged mainly in solid nested
pattern. The tumor cells revealed epithelioid morphology, abundant clear to eosinophilic
granular cytoplasm with heavy melanin pigments, and round nuclei with occasional
nucleoli. No tumor necrosis, no atypical mitotic ﬁgure, and no pleomorphism was foundin the specimen. Lymphovascular invasion was observed. Melanin pigments were
demonstrated by Fontana-Masson special stain. Immunohistochemically, the tumor
cells were immunoreactive to TFE3, focally positive to HMB45, while negative for PAX8,
Melan-A, SOX10, and S100. Ki-67 proliferative index was 1-2%. According to themorphology and immunohistochemical studies, melanotic Xp11 translocation renal
cancer / PEComa was diagnosed. Due to its large size (> 5 cm), uncertain malignant
potential was indicated.2
The differential diagnosis may include classic angiomyolipoma (AML) / PEComa,melanoma, and TFE3-rearranged renal cell carcinoma. The abundant melanin pigment
and immunoreactivity to HMB45 may arouse worries about melanoma. However, primarymelanoma arising from kidney is rare. Negativity for SOX10 and S100, and positivity for
TFE3 rule out the diagnosis of melanoma. Also, negativity for PAX8 can rule out the TFE329

rearranged renal cell carcinoma. Xp11 translocation PEComa is different from classic
AML / PEComa of the kidney in the various aspects. The population of patients of theformer are young and female predominant, and the clinical behavior is more aggressive.
They almost have an exclusively epithelioid clear cell morphology, while both classic
AML and epithelioid AML may show component of spindle cell morphology.
Immunohistochemically, Xp11 translocation PEComa shows minimal to absent
immunoreactivity for muscle markers. TSC1 or TSC2 genes alteration, or a clinicalassociation with tuberous sclerosis are not seen.3,4 According to the literature, tumor
size >5 cm, inﬁltrative growth pattern, high nuclear grade, necrosis, and mitotic activity>1/50 HPF are associated with subsequent aggressive clinical behavior.2
Reference:
1. Argani Pedram et al. (2016) TFE3-Fusion Variant Analysis Deﬁnes Speciﬁc
Clinicopathologic Associations Among Xp11 Translocation Cancers. Am J Surg
Pathol, 40(6):723–737.
2. Folpe, Andrew L, et al. (2005) Perivascular Epithelioid Cell Neoplasms of Soft Tissue
and Gynecologic Origin A Clinicopathologic Study of 26 Cases and Review of the
Literature. Am J Surg Pathol, 29(12): p 1558-1575
3. Holger Moch, et al. TFE3-rearranged renal cell carcinomas. In: WHO Classiﬁcation of
Tumours Editorial Board. Urinary and male genital tumours [Internet]. Lyon (France):
International Agency for Research on Cancer; 2022 [cited 2024 Feb 16]. (WHOclassiﬁcationoftumours

series,

5th

ed.;

vol.

8).

Availablefrom:https://tumourclassiﬁcation.iarc.who.int/chaptercontent/36/25
4. Epithelioid angiomyolipoma / epithelioid PEComa of the kidney. In: WHOClassiﬁcation of Tumours Editorial Board. Urinary and male genital tumours [Internet].
Lyon (France): International Agency for Research on Cancer; 2022 [cited 2024 Feb
16]. (WHO classiﬁcation of tumours series, 5th ed.; vol. 8). Available from:https://tumourclassiﬁcation.iarc.who.int/chaptercontent/36/33

30

Poster 3 (P-3)
A case of spermatocytic tumor
松浦悠実 Yumi Matsuura, Shintaro Takahashi, Yasuto Fujimoto, Yuka Mikami, Hirotake
Nishimura, Takuya Moriya
Kawasaki Medical School
A man in his 50s consulted a urologist due to a mass in his right testicle. Contrastenhanced magnetic resonance imaging revealed a round mass approximately 23 mm indiameter, showing homogeneous contrast and diffusion restriction. Blood tests showedhuman chorionic gonadotropin (HCG) <2.3 mIU/mL, alpha-fetoprotein (AFP) 3.5 ng/mL,
and lactate dehydrogenase (LDH) 157 U/L, prompting suspicion of a seminoma, leading
to a high orchiectomy.
Upon gross examination, a well-deﬁned white-toned mass was observed in the testis.
Histologically, the tumor exhibited three types of round tumor cells of varying sizes, with
the nuclear chromatin of intermediate and giant cells appearing granular or ﬁlamentous
patterns. Mitotic ﬁgures, including atypical forms, were scattered, with minimal
lymphocytic inﬁltrates. The presence of germ cell neoplasia in situ (GCNIS) remained
uncertain. Immunohistochemistry revealed SALL4 positivity in tumor cells, partial weak
positivity for c-KIT, and negativity for OCT-3/4 and D2-40 with no GCNIS detected.
Consequently, a diagnosis of spermatocytic tumor was established.
Spermatocytic tumors, classiﬁed as GCNIS-unrelated germ cell tumors by the World
Health Organization, are rare, constituting approximately 1% of testicular germ celltumors. While microscopically similar to seminomas, they differ in the describedcharacteristics. Given their typically benign course, it is important to differentiate themfrom seminomas, which have distinct prognoses. Accurate diagnosis depends on
disease recognition and careful observation of HE staining, supplemented by the active
use of immunohistochemistry for assistance.

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Poster 4 (P-4)
A case of gastric lipoma mimicking well differentiated liposarcoma
藤本康人 Yasuto Fujimoto, Syunsuke Yorifuji, Seiya Kinoshita, Tatsushi Shiomi and
Takuya Moriya
Kawasaki Medical School
A patient is a 45-year-old woman. She presented with shortness of breath on exertionand melena from a week ago, and visited our emergency room. Blood tests revealed
iron deﬁciency anemia, and contrast-enhanced computed tomography (CT) showed no
obvious extravasation, but a ruptured gastric submucosal tumor (SMT) was suspected.
Endoscopy exhibited a snowman-shaped SMT over 50 mm in size extending fromgastric angle to greater curvature of antrum. Endoscopic ultrasonography (EUS)
showed a homogenous hyperechoic tumor contiguous with the submucosa. Contrastenhanced magnetic resonance imaging (MRI) revealed a tumor composed of fatty
components, with no internal enhancing components, and was considered to be alipoma clinically. An endoscopic biopsy specimen from the tumor showed a fatty
stromal component, with some cells that appeared atypical histopathologically. The
tumor was considered to have adipose differentiation, but it was diﬃcult to determine
whether it was benign or malignant. A pyloric gastrectomy was performed for
diagnostic and therapeutic purposes. The surgical specimen microscopically showed atumor composed mainly of mature adipose tissue, accompanied by an intervening
component of spindle-shaped stromal cells proliferating with collagen ﬁbers. The
adipocytes of variable size and atypical-looking nuclear enlargement of adipocytes andstromal cells were identiﬁed. Inﬂammatory cell inﬁltration was also seen in someareas. Immunohistochemically, MDM2 focal weakly-positive, CDK4 focal weaklypositive, p16 focal positive, CD34 positive (stromal cells), and Rb positive (retained
expression). No signiﬁcant increase in Ki-67 (MIB-1) labeling index was observed. In
addition, FISH performed at that facility showed no ampliﬁcation of the MDM gene.
Based on these ﬁngdings, a diagnosis of lipoma (atypical) was made, with a welldifferentiated liposarcoma being ruled out. The postoperative course is uneventful, andno recurrence. Although gastric lipomas are rare benign tumor (accounting for only 5%of all gastrointestinal primary lipomas and less than 1% of gastric tumors), the32histological diagnosis is usually straight forward. We report the case of lipoma withatypia in which we had diﬃculty in differentiating from well differentiated liposarcoma.

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Poster 5 (P-5)
An autopsy case of a patient with myotonic dystrophy
古味和晃 Kazuhiro Komi, Hirotake Nishimura, Yukari Nagasaki, Takayuki Konishi and
Takuya Moriya
Kawasaki Medical School
Here we present an autopsy case of a 60-year-old woman with a history of myotonic
dystrophy (DM1) lasting approximately 45 years. Clinically, she presented with gait
disturbance, hachet face, and grip myotonia, while genetic testing revealed prolonged
CTG repeats (1000 repeats). At autopsy, the patient’s ﬁxed brain weight was 1090 g.
Atrophy of the gross frontal lobe and parahippocampal gyrus was observed, while
neuroﬁbrillary tangles were histologically observed in the parahippocampal gyrus.
Immunostaining for anti-phosphorylated tau (AT8) revealed positive ﬁndings from thelimbic system to the lower temporal lobe (AT8 stage III), with no positive ﬁndings foramyloid beta. Although the pathological ﬁndings were consistent with primary agerelated tauopathy, tau pathology was observed not only in the limbic system, but also
extensively in the brainstem and spinal cord. Plaque-like structures were observed in
the midbrain tegmentum. Furthermore, positive ﬁndings were observed in gray matterneurons and neurites in the spinal cord. No alpha-synuclein pathology or positiveﬁndings for pTDP-43 were observed. Nuclei in the skeletal muscle were arranged in achain-like pattern. Other organs exhibited mild pneumonia, fatty degeneration ofhepatocytes, pancreatic cysts, and adenomatous goiters. However, no signiﬁcantmorphological changes were observed in the endocrine organs.
DM1 is a systemic disease well-known among medical students in Japan. However,autopsy pathology can pose a challenge for pathologists as it requires deep knowledgeof central nervous system and muscle pathology.

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Poster 6 (P-6)
Conventional spindly malignant peripheral nerve sheath tumor
arising from a schwannoma with SH3PXD2A::HTRA1 fusion
李致豪 Chih-Hao Li, Hsuan-Ying Huang
Department of Anatomic Pathology, Kaohsiung Chang Gung Memorial Hospital,
Kaohsiung, Taiwan
Schwannomas are common benign peripheral nerve sheath tumors, consisting nearlypurely of neoplastic schwannian cells. At the molecular level, NF2 inactivating mutation
represents the crucial genetic alteration in up to 75% of sporadic schwannomas.
Recently, a fusion between the SH3PXD2A and HTRA1 genes is proposed as analternative tumorigenic mechanism, present in approximately 10% of cases, andsigniﬁcantly associated with a “serpentine palisading” histological pattern. Malignant
transformation of schwannomas is scarce and, once occurring, mostly takes the formof epithelioid malignant peripheral nerve sheath tumor (MPNST), with the occurrenceof conventional spindly MPNST being ultrarare in schwannomas. Herein, we describe aspindly MPNST associated with a schwannoma harboring SH3PXD2A::HTRA1 fusion,
manifesting as a pre-sacral mass in a 56-year-old female. The patient had a left breast
cancer (invasive carcinoma of no special type) post treatment in 2019. She presented
with soreness over lower back in October 2021. Computerized tomography (CT) scansrevealed a 9 cm tumor at pre-sacral region, for which surgical excision was performed.
Histologically, there were juxtaposed hypercellular and hypocellular components, withcompact fascicles of hyperchromatic spindle cells with frequent mitoses in the former.
The hypocellular component showed plump to oval cells arranged in a distinctive“serpentine palisading” pattern with bland-appearing cytology without mitosis.
Immunohistochemically, SOX10 reactivity is focal and patchy in the MPNST area but
diffuse in the schwannomatous component, while the expression of both H3K27me3
and INI1 is retained in both components. Furthermore, a fusion between SH3PXD2A(exon 6) and HTRA1 (exon 2) was detected in both components by RT-PCR with
conﬁrmatory Sanger sequencing and BaseScope RNA in situ hybridization, hence
arriving at the diagnosis of spindly MPNST arising from a fusion-positive schwannoma.
The patient received adjuvant radiotherapy (60 Gy in 30 fractions) because of positive
surgical margins, while local recurrence was noted in May 2022. According to follow-up
35

imaging studies, this patient developed widespread metastases to the lung, liver, andbone and expired in January 2023. Spindly MPNST arising in a schwannoma is
ultrarare. Recognizing the “serpentine palisading” histological pattern in the
schwannomatous component is helpful to guide the potential cases for molecular
detection of the SH3PXD2A::HTRA1 fusion.

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Poster 7 (P-7)
Cytoplasmic lipid droplets and adipophilin expression correlate withpoor prognosis in diffuse large B-cell lymphoma
王淑嫻 Shu-Hsien Wang, MD, and Kung-Chao Chang, MD, PhD*
Department of Pathology, National Cheng Kung University Hospital, College ofMedicine, National Cheng Kung University, Tainan, Taiwan* Correspondence:
Kung-Chao Chang, MD, PhD, Department of Pathology, National Cheng Kung University
Hospital, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road,
Tainan, 704 Taiwan. Tel.: +886-6-235-3535 ext. 2636; Fax: +886-6-276-6195; E-mail:changkc@mail.ncku.edu.tw
Burkitt lymphoma, a neoplasm with the highly rapid turnover, is characterized bycytoplasmic vacuoles, which are best revealed by vital staining smears. The
cytoplasmic vacuoles have been demonstrated to be lipid droplets (LDs), which aredecorated by perilipin 2 (adipophilin). The phenomenon of cytoplasmic vacuoles (LDs)is universal and thus plays no role in prognosis of patients with Burkitt lymphoma. In
contrast, cytoplasmic vacuoles (LDs) seem not to be a ubiquitous feature in diffuse
large B-cell lymphoma (DLBCL) and their role in clinicopathologic characters of DLBCL
patients would be intriguing. DLBCL is the most common type of malignant lymphoma
and its molecular classiﬁcation carries prognostic signiﬁcance and therapeutic
implication, including one type characterized by metabolic reprogramming withenhanced lipogenesis, which is reﬂected by cytoplasmic LDs and represented bycytoplasmic vacuoles in cytology smears. We, thus, aimed to test the role of lipid
biogenesis in clinicopathologic features of DLBCL patients. The study cohorts werecomposed of three groups: 1) DLBCL patients with lymphomatous effusional cytology
smears available (n=52); 2) DLBCL cases with imprint cytology smear available onfrozen sections during intraoperative consultation (n=32); and 3) DLBCL cases withsolid lymphoma tissues for adipophilin immunostaining (n=85). The cytology smears
were reviewed by two pathologists and percentage of tumor cells among all nucleatedcells and percentage of tumor cells with LDs were evaluated by oil immersion at 10
ﬁelds. For selected cases, ﬂow cytometry and/or cell blocks with37

immunohistochemical staining were performed to validate tumor involvement. We ﬁrst
validated cytoplasmic vacuoles to be lipid droplets by Oil-red-O stain, ﬂuorescent
Bodipy stain and electron microscopy examination. Then, we found that thephenomenon of cytoplasmic vacuoles in DLBCL cells was present more frequently ineffusion specimens than in solid tumor imprinting specimens (32.7% [17/52] vs. 9.4%
[3/32], p=0.015, Fisher exact test). Since DLBCL with lymphomatous effusion was apoor prognosticator than those without, even worse than stage IV disease (Am J Clin
Pathol 2015;143(5):707-15), it indicates that lymphoma cells in effusions may
represent a more aggressive biology behavior than those in solid tumors, as presented
with many cytoplasmic LDs, that is, enhanced lipogenesis. In addition, DLBCL patients(n=52) with LDs in effusional lymphoma cells carried a worse prognosis (p=0.029, logrank test), had a higher International Prognostic Index (IPI) score (94% vs. 66%,
p=0.026), and showed a trend for higher LDH serum levels (>225 IU/L, 100% vs. 82%,
p=0.065) and high-stage disease (stages III-IV; 100% vs. 80%, p=0.060) than those
without LDs in effusional lymphoma cells. Moreover, using adipophilin as a surrogate
marker for the presence of LDs, we found that in another cohort of DLBCL (n=85),
expression of adipophilin in solid tumor cells predicted a poorer prognosis than those
without adipophilin expression (p=0.007, log-rank test), correlated with a higher IPI
score (63% vs. 30%, p=0.005), and showed a trend for higher LDH levels (79% vs. 58%,
p=0.073). To the best of our knowledge, we are the ﬁrst to show that presence of LDs
predict poorer prognosis in DLBCL patients with lymphomatous effusions andexpression of adipophilin predicts poorer prognosis in patients with solid DLBCL. Ourﬁndings, therefore, highlight the role of LDs and adipophilin expression in prognostic
prediction in patients with DLBCL and suggest that cytologic examination oflymphomatous effusions with LDs should be routinely performed for prognostic andtherapeutic stratiﬁcation.

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Poster 8 (P-8)
A case of pulmonary metastasis with interstitial spread of sinonasal
adenoid cystic carcinoma
松野岳志 Takeshi Matsuno, Takae Inayoshi, Hironori Miyake, Takashi Matsutani,
Hirotake Nishimura, Tatsushi Shiomi, Takuya Moriya
Kawasaki medical school
A 64-year-old woman was diagnosed with sinonasal adenoid cystic carcinoma(cT4N0M0, cStage IVB) and underwent induction chemotherapy and proton beam
therapy. 4 years later, the ﬁrst local recurrence was detected. At the same time,
Computerized tomography (CT) revealed a partial solid ground glass nodule (24mm insize) in the right upper lobe. As this lesion was suspected to be primary lungadenocarcinoma, a wedge resection of the right upper lobe was performed.
Grossly, a grey-white solid mass was observed in the surgical specimen. Histologically,
the mass was composed of atypical cells proliferating with tubular, cribriform and solid
structures. At the margins of the lesion, tumor cells inﬁltrated into the alveolar septa(so-called interstitial spread), and overlying pneumocytes exhibited hyperplasticchange and nuclear atypia.
Immunohistochemically, two types of cells were recognized. One was a distribution ofepithelial cells showing cytokeratin (CK) AE1/AE3, CK 5/6 positivity. The other was aproliferation of cells with positive of myoepithelial markers, such as p40, p63, and α
SMA. C-Myb was also partially positive in myoepithelial cells of the lesion. TTF-1 andNapsin A were positive for overlying pneumocytes, but negative for tumor cells.
On the basis of the above ﬁndings, we have made a diagnosis of pulmonary metastasisof sinonasal adenoid cystic carcinoma. When metastatic tumor cells spread within thealveolar septa and accompanied by hyperplastic change and nuclear atypia of
pneumocytes, it may be diﬃcult to distinguish from primary lung adenocarcinoma
histologically. In order to diagnose correctly the tumor exhibiting interstitial spread, it isimportant to consider the clinical course and immunostaining ﬁndings together.

39

Poster 9 (P-9)
A case of adult granulosa cell tumor with sex cord tumor withannular tubules-like morphology, both of which have a common
mutation of FOXL2 p.C134W.
喜多村恭平 Kyohei Kitamura, Yuki Teramoto, Naoki Goda, Hiroaki Ito, Sachiko
Minamiguchi, Hironori Haga
Department of Diagnostic Pathology, Kyoto University Hospital
Adult granulosa cell tumor (AGCT) is a tumor composed of granulosa cells growing in avariety of patterns. FOXL2 C134W mutation is a characteristic mutation of AGCT1.
Sex cord tumor with annular tubules (SCTAT) is a rare tumor, accounting for <1% of allsex cord tumors. It shows characteristic ring-like tubules with basement membrane-likematerials (annular tubules). Few reports show the relationship of AGCT with SCTAT.
Herein, we report a case of AGCT with SCTAT-like morphology, which has a common
mutation of FOXL2 p.C134W.
The patient is a postmenopausal woman in her 60s. In a previous hospital, a 9.0 cm left
ovarian tumor was found, and the patient was followed up. Six months later, she felt
abdominal distention and pain. Abdominal ultrasound showed ascites and the tumor
had increased to 12 cm in size. Then she was referred to Kyoto University Hospital.
Blood tests showed low FSH and high estrogen (E2) levels. Based on these ﬁndings
and MRI, AGCT was suspected. Total hysterectomy, bilateral salpingo-oophorectomy,
partial omentectomy, and peritoneal biopsy were performed.
Grossly, the left ovarian tumor was 15.0 x 13.0 x 3.0 cm in size with a ruptured capsule.
The contents were yellow to tan solid tumor with hemorrhage.
Microscopically, the tumor exhibited various growth patterns. A diffuse pattern ofsheet-like growth with dilated vessels was predominant, while a trabecular pattern,
microfollicular pattern, and “watered silk pattern” were observed. Tumor cells had scantcytoplasm, oval nuclei, prominent nucleoli, and coffee bean-like nuclear grooves. CallExner bodies were found. These ﬁndings were compatible with AGCT.
In addition, ring-like tubules with basement membrane-like materials were observed at
the periphery. This was a SCTAT-like pattern. Immunohistochemically, both AGCT and
SCTAT-like components were positive for FOXL2. For further investigation, we
performed Sanger sequencing in both components. The result revealed both had the40same FOXL2 C134W mutation, indicating that AGCT showed SCTAT-like morphology.
This is the second case of AGCT with SCTAT-like morphology, which showed theiridentical mutation proﬁle2.
1. Jamieson S, et al. The FOXL2 C134W mutation is characteristic of adult granulosa
cell tumors of the ovary. Mod Pathol. 2010;23:1477-1485.
2. Chang RJ, et al. Sex Cord Tumor With Annular Tubules-Like Histologic Pattern in
Adult Granulosa Cell Tumor: Case Report of a Hitherto Unreported Morphologic
Variant. Int J Surg Pathol. 2021;29:433-437.

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The 8th Japan-Taiwan Conjoint Slide Conference Secretariat☆ Yuki Teramoto (web designer & booklet editor)☆ Kaoru Ijiri (progress manager & tour coordinator)☆ Yukako Nakajima (venue setting up & registration)☆ All staff of the Department of Diagnostic Pathology, Kyoto University Hospital

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