bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiorgan Sarcoidosis-Like Reaction Mimicking Metastatic Disease in Microsatellite Instability-High Melanoma Patient Treated With Checkpoint Inhibitor Nivolumab
Authors: Jagannathan Geetha , Bernabeu Belen Quereda , Tuluc Madalina 
Published: September 2019

Abstract

Introduction
Melanomas and tumors with high microsatellite instability (MSI-H) carry heavy tumor mutation burden. The resulting neo-antigens elicit a host immune response in an attempt to contain the tumor. Immune checkpoint pathways (PD-1/PD-L1 and CTLA-4) downregulate T-cell activation, limiting damage to healthy tissue during physiologic immune response. Tumors take advantage of these pathways as a mechanism of immune escape. Checkpoint inhibitors (CPIs) such as Nivolumab (PD-1 inhibitor) and others inhibit these pathways, allowing immune-mediated destruction of tumor cells. Unsurprisingly, these drugs are associated with a spectrum of immune-related adverse effects (irAEs). We report a case of a patient with MSI-H metastatic melanoma who developed an unusual irAE during nivolumab immunotherapy.

Case Report
A 35-year-old man with a history of ocular melanoma presented with omental metastasis. The metastatic focus was MSI-H by NGS with deficient MSH1/PMS2 by immunohistochemistry. Nivolumab therapy was initiated. Initial follow-up imaging showed complete response. At 7 months, clinical exam and PET imaging showed new skin nodules, hypermetabolic mediastinal lymphadenopathy, and a hypermetabolic vertebral (L3) lesion concerning for disease progression. Biopsies from all three sites revealed sarcoidosis-like granulomatous inflammation. Special stains for fungus and mycobacteria and microbial cultures were negative. The patient was asymptomatic and did not require antisarcoid treatment. He remains in remission for melanoma.

Conclusion
Sarcoidosis-like reaction is a rare irAE of CPIs that can clinically/radiologically mimic metastatic disease. Bone involvement as seen in our patient is extremely rare. Importantly, biopsy/histopathological examination is required to rule out disease progression. Infectious causes for granulomas should be excluded as these patients are immunocompromised. Evidence suggests that irAE with CPIs may be associated with better outcomes. MSI-H status is infrequent in melanomas but is hypothesized to be a predictive biomarker for CPI response. Our patient is predicted to do well.
Adequacy of Tissue Sampling in Breast Specimen
Authors: Khawar Sidrah , Hamza Ameer , Alrajjal Ahmed , Salehi Sajad , Qu Hong 
Published: September 2019

Abstract

Objectives
Due to inadequate sampling concerns, pathologists frequently request additional tissue sections (ie, more tissue sections in addition to initial representative sections) in breast specimens. This study explores the effectiveness of the additional tissue sections in the breast specimens.

Methods
Breast specimens received in our institution on which additional tissue sections were requested were included in the study. Pathology reports and glass slides for these specimens were reviewed. Additional tissue sections were considered effective if they changed the final diagnosis altogether, changed a benign entity to borderline or malignant category, changed pathologic tumor stage, changed margin status, changed tumor focality, or if lymphovascular invasion was identified.

Results
A total of 325 specimens were identified. Of these, 98 (30.1%) were benign while 224 (68.9%) were malignant. Among malignant cases, 53 (23.7%) had neoadjuvant therapy. Overall mean initial representative sections submitted were 15.1 ± 8.7 while additional tissue sections were 10.7 ± 8.0. There was no difference in additional sections submitted for benign versus malignant cases (9.8 ± 7.7 vs 11.2 ± 8.0; P = .96). Also there was no difference in additional sections submitted for cases with neoadjuvant therapy versus those without any therapy (10.4 ± 6.9 vs 11.6 ± 8.4; P = .36). Twenty-five (7.7%) specimens benefited from submission of additional tissue sections. All 25 cases were malignant; 7 had neoadjuvant therapy while 18 did not. No tumor was identified in initial representative sections in 6 cases, pathologic tumor stage was changed in 12 cases, margin status changed in 2 cases, tumor focality changed in 4 cases, and an extra positive lymph node was identified in 1 case.

Conclusion
Additional tissue sections contributed to final diagnosis in 7.7% cases. Surgical pathology breast specimens require specialized handling and thorough sampling for accurate diagnosis and staging.
Maxillary Ameloblastoma With Pulmonary Metastasis: Management Challenges in Resource-Limited Setting—A Case Report
Authors: Mlaga Salvatory , Brown Tupokigwe , Malango Atuganile , Sohal Karpal , Vuhahula Edda 
Published: September 2019

Abstract
Introduction: Ameloblastoma is a benign odontogenic tumor that may exhibit aggressive biological behavior with local recurrence. It more commonly occurs in the mandible than the maxilla. Rarely, ameloblastoma may metastasize to local regional lymph nodes and/or distant organs, notably lungs, brain, and skin, hence the term metastasizing (malignant) ameloblastoma (MA), in keeping with the WHO definition of MA in its recent classification of odontogenic tumors (2017). Here, we report a rare case of maxillary ameloblastoma that metastasized to the lungs in a 22-year-old African male. Radiological evaluation revealed a massive maxillary tumor that had a local extension to the brain. Chest x-ray and CT scan pointed out metastatic mass to the lungs. Histology of the tumor mass revealed it to be follicular ameloblastoma with aggressive behavior shown by abnormal mitoses and further characterization by immunohistochemical reactivity to Ki-67. CT-guided fine-needle aspiration cytology of the lung mass showed microscopic features of ameloblastoma bearing resemblance to the primary jaw tumor. Socioeconomic constraints on the patient’s side and limited medical resources necessitated planning that served the purpose of proper diagnosis and treatment options. In this paper, we discuss the clinical behavior, differential diagnosis, and challenges faced by clinicians in managing metastatic ameloblastoma in a resource-limited setting. Conclusively, reporting this rare case and first of its kind in our locality raises awareness, hence reducing misdiagnosis of primary tumor in sites other than the jaw, while also sharing our experience of managing metastasizing ameloblastoma in a resource-limited setting to the larger medical community.
Uterine Tumors Resembling Sex Cord Stromal Tumors: A Distinctive Entity to Consider in Evaluating the Adenosarcoma
Authors: Sameeta Fnu , Haque Monira , Haleema Sadia , Roveda Kelly , Mneimneh Wadad 
Published: September 2019

Abstract

Objectives
Uterine tumors resembling ovarian sex cord tumors (UTROSCTs) are rare neoplasms. Approximately 60 cases of UTROSCT are reported in the literature.

Methods
A 53-year-old female was referred to our institution for definitive surgery following an endometrial biopsy diagnosed as adenosarcoma of the uterus. Her history and physical examination were unremarkable. CT scan showed no evidence of metastatic disease. She underwent a staging hysterectomy with bilateral salpingo-oophorectomy. Grossly, a polypoid mass was seen in the uterine cavity with extension into the myometrium.

Results
Histologic examination of the mass revealed anastomosing cords and nests of epithelioid cells with bland ovoid nuclei, inconspicuous nucleoli, and scant eosinophilic cytoplasm, embedded within a fibromuscular stroma, resembling sex cord stromal tumors of the ovary. Cellular atypia, necrosis, or mitotic activity were not noted. Immunohistochemically, the neoplastic cells expressed cytokeratin AE1/AE3, WT1, CD99, calretinin, inhibin, melan A, and estrogen receptor. These features were consistent with the diagnosis of UTROSCT.

Conclusion
UTROSCT accounts for less than 0.5% of all uterine malignancies. These tumors arise in perimenopausal females and historically follow a benign course. Although their histomorphologic and polyphenotypic immunoprofile such as sex cord, epithelial, and myoid seems to be unique among uterine mesenchymal neoplasms and can be diagnostically useful, their diagnosis can be confused with more common tumors such as low-grade stromal sarcomas, carcinosarcoma, and adenosarcoma, especially in superficial endometrial biopsies. As in our case, the initial endometrial biopsy, being superficial, revealed endometrial polyp with rare component of sex cord stromal elements, misleading to the diagnosis of adenosarcoma. However, microscopic examination of the hysterectomy specimen revealed the bulk of the sex cord tumor elements within the myometrium, which was not accessible to biopsy. This case, apart from being rare, also highlights the importance of considering this tumor in the differential diagnosis in superficial endometrial biopsies.
Ameloblastic Fibroma: A Rare Entity of the Mandible
Authors: Sakshi Sakshi , Kuklani Riya 
Published: September 2019

Abstract
Ameloblastic fibroma (AF) is an uncommon benign odontogenic true mixed tumor comprising neoplastic epithelial and mesenchymal tissues. It constitutes only approximately 2% of odontogenic tumors and is defined by the World Health Organization (WHO) as “neoplasm composed of proliferating odontogenic epithelium embedded in cellular ectomesenchymal tissue that resembles the dental papilla and epithelial strands and varying degrees of inductive changes and dental hard tissue formation.” The tumor is most common in the first and second decades of life with a slight male predilection. The most common site is the posterior mandible and 75% of the cases are associated with an unerupted tooth. Radiologically, it may present as a unilocular or multilocular lesion. The treatment of choice could range from aggressive curettage for a small unilocular lesion to wide local excision for a large multilocular lesion. The prognosis is usually good, with a recurrence rate of approximately 20%.
Here we present a case of a 13-year-old male with a multilocular expansile cystic lesion associated with nonvital tooth 20 and tooth 21 since 2016. An incisional biopsy was performed and the microscopic examination revealed small masses of cellular fibrous and myxoid connective tissue containing long narrow cords of odontogenic epithelium. The odontogenic islands were basophilic with peripheral nuclear palisading of the basal cell layer, consistent with an ameloblastic fibroma. Complete curettage was performed and the patient is being followed up with no recurrence since 2 months.
We reviewed the literature with regard to clinical, histopathological, and radiological findings and reached the conclusion that malignant transformation of ameloblastic fibroma into ameloblastic fibrosarcoma is uncommon but well documented. AF needs to be distinguished from ameloblastoma and ameloblastic fibrosarcoma, since these two tumors can be locally invasive and have greater potential for recurrence than ameloblastic fibroma.
Rare Case of Metastatic Ovarian Clear Cell Carcinoma With an In Vitro Fertilization Pregnancy
Authors: Inamdar Arati , Loo Abraham 
Published: September 2019

Abstract
The risk of ovarian malignancy is rare in pregnancy with a reported incidence of approximately 1 in 50,000. Ovarian clear cell carcinoma (OCCC) accounts for 5% to 10% of all ovarian carcinomas with mean age of 50 to 55 years and is often associated with endometriosis. We present a case of 38-year-old G2P1 Asian female with an in vitro fertilization pregnancy and history of endometriosis who presented with the right adnexal mass. The transvaginal ultrasound performed during the early pregnancy was suggestive of endometrioma or desmoid tumor. At 32 weeks, the patient presented to the emergency department with preeclampsia and severe headache. An emergency cesarean section was performed due to worsening of the patient’s condition. An ovarian mass arising from the right ovary and with a friable and hemorrhagic internal surface was excised, which weighed 63 g and measured 14.0 × 10.5 × 3.0 cm. Its external surface was smooth, hemorrhagic, but without any excrescences. The serial sectioning revealed multiple cystic lesions filled with necrotic material overall occupying 80% of the mass. Microscopically, the viable ovarian tissue demonstrated tubulocystic/papillary architecture lined by hyperchromatic hobnail cells along with focal areas of solid sheets of tumor cells displaying clear cytoplasm. Immunohistochemical stains for Wilm’s tumor 1 and p53 were negative while positive for PAX8. These findings were indicative of OCCC without overexpression of wild-type p53. The PET scan performed few weeks after delivery showed widespread metastasis. We present a unique case of metastatic OCCC removed at the time of cesarean section in the late-preterm period. Our case not only emphasizes the need for definitive treatment option for endometriosis but also a close imaging surveillance of all masses diagnosed during pregnancy in women with risk factors such as endometriosis and Asian ethnicity. Furthermore, our study advocates the need for possible guidelines for management of such rare cases.
Ovarian Endometrioid Borderline Tumor With Massive Squamous Differentiation: A Case Report
Authors: Khedr Maha , Chen Adam , Liu Weiguo 
Published: September 2019

Abstract

Introduction
Ovarian endometrioid borderline tumor is uncommon and constitutes only 0.2% of all epithelial ovarian tumors. Many patients have associated endometriosis, and coexisting endometrial hyperplasia and/or carcinoma is commonly present.

Methods
Here we report an ovarian endometrioid borderline tumor with massive squamous differentiation. The peculiar histologic features made the diagnosis of this uncommon entity even more challenging. The patient was a 43-year-old female with a history of chronic pelvic pain. A pelvic ultrasound showed a 7.9-cm complex solid and cystic right ovarian mass and a hypoechoic left ovarian mass. Patient underwent a hysterectomy with bilateral salpingo-oophorectomy. Grossly, the right ovary showed a 2.5-cm solid and cystic lesion with focal papillary inner surface. Microscopic examination showed uterine adenomyosis with serosal endometriosis. The left ovary showed endometriosis with atypical hyperplasia. Initial representative sections from the right ovary demonstrated extensive squamous cell proliferation with papillary architecture. The squamous cells had pink or clear cytoplasm, intracellular bridging, irregular nuclei, and prominent nucleoli. Immunostains confirmed the squamous differentiation. Based on the histologic features and immunophenotype, a well-differentiated squamous cell carcinoma was considered one of the differential diagnoses. However, further examination of additional sections from entirely submitted lesion showed some areas with classic morphologic features of endometriosis with atypical hyperplasia. With the consideration of clinical-pathological correlations, a diagnosis of endometrioid papillary cystic borderline tumor with massive squamous differentiation was rendered and close follow-up was recommended. The patient was doing well at 4-month postoperative follow-up.

Conclusion
We present this case to emphasize (1) extensive squamous metaplasia arising in endometriosis can make the rendering of a definitive diagnosis challenging. (2) Primary squamous cell carcinoma of ovary is very rare. (3) Careful sampling is very important for achieving a precise pathologic diagnosis.
Low-Grade Fibromyxoid Sarcoma: A Rare Case in an Unusual Location
Authors: Perez Diandra , El-Zammar Ola , Naous Rana 
Published: September 2019

Abstract

Introduction
Low-grade fibromyxoid sarcoma, also known as Evans tumor, is a low-grade sarcoma that most commonly arises in the deep soft tissue of the proximal extremities or trunk in young adults. It is very rare in the viscera as a primary site with only a few cases reported in the literature. Here we present a case of Evans tumor occurring in an unusual and rarely reported location: the mediastinum.

Method
A 32-year-old male presented with history of persistent cough, and subsequent imaging revealed a left diaphragmatic tumor measuring around 11 cm with associated chest wall implants. Grossly, the tumor was well circumscribed, arising from the parietal pleura with attachment to both lung and diaphragm and focally involving visceral pleura with no extension into the underlying lung parenchyma. Histologically, the tumor was composed of uniform and bland-appearing spindle cells interspersed among large areas of hyalinized rosettes, so-called giant rosettes. By immunohistochemistry, the tumor was positive for EMA, bcl-2, TLE-1, and MUC-4 and negative for STAT-6, ruling out solitary fibrous tumor. FISH for SYT gene rearrangement was performed and was negative, ruling out synovial sarcoma. Given the overall morphology and the phenotype, the final diagnosis was low-grade fibromyxoid sarcoma with giant collagen rosettes (also known as hyalinizing spindle cell tumor with giant rosettes).

Conclusion
Mediastinal low-grade fibromyxoid sarcoma is a rare entity that should be considered in the differential diagnosis of visceral soft tissue tumors. Pathologic examination and a thorough immunohistochemical and molecular workup play a vital role in establishing this rare and challenging diagnosis.
Clinicopathologic Characterization of Early Onset Endoscopically Unresectable Adenomas (EOEUAs)
Authors: Saade Rayan , Fu Zhiyan , Lee Hwajeong 
Published: September 2019

Abstract

Objectives
Early onset colorectal carcinoma (CRC), defined as CRC detected in patients ≤50 years old, are frequently located in the distal colorectum and are associated with risk factors that are common to adenoma. We examined the risk factors, pathologic features, and clinical implications associated with EOEUA.

Methods
A retrospective cohort of 154 patients with EOEUA was retrieved. Clinical data were obtained from electronic medical records. A minimum of 12 months follow-up was considered valid follow-up data. Archived pathology slides were evaluated for the presence of high-grade dysplasia (HGD) and Paneth cells (PCs) in adenomatous crypts. Additional pathologic data were retrieved from pathology reports. The patients were stratified into age >50 vs ≤50 years. Fisher’s exact test and Student t test were performed when indicated (P < .05 was considered statistically significant).

Results
In the ≤50-year group, EOEUAs were common in the rectosigmoid colon compared to >50-year group (41.2% vs 16.8%; P = .025). The association with diabetes, obesity, and alcohol consumption was similar in the two groups, whereas the incidences of hypertension, hyperlipidemia, and smoking were significantly lower in the ≤50-year group. No significant differences in gender distribution, adenoma size, HGD, PC presence, and future adenoma burden were observed between the two groups.

Conclusion
The association with established risk factors of adenoma to include diabetes, obesity, and alcohol consumption in EOEUA is comparable to that of older patients. In contrast, hypertension, hyperlipidemia, and smoking do not appear to be associated with an increased risk of endoscopically unresectable adenoma in this age group. Similar to early onset CRC, EOEUAs are common in the rectosigmoid, supporting the premise that flexible sigmoidoscopy may be a viable screening alternative in this age group, especially for patients with diabetes, obesity, or alcohol history.
Two Cases of Plexiform Angiomyxoid Myofibroblastic Tumor (PAMT) of Gastrointestinal (GI) Tract: One With 8-Year Follow-up, One in Distal Jejunum
Authors: Arslan Mustafa Erdem , Jennings Timothy , Li Hua , Lee Edward , Nigam Ankesh , Lee Hwajeong 
Published: September 2019

Abstract

Objectives
PAMT is an exceedingly rare mesenchymal tumor of the gastric antrum that was first described in 2007. Although likely benign, long-term follow-up is limited due to its recent description and rarity. In small bowel, only four cases of PAMT have been reported, two in duodenum and two in proximal jejunum.

Methods
(A) A 16-year-old female presented with GI bleeding and gastric outlet obstruction. Imaging studies suggested a gastrointestinal stromal tumor (GIST) arising in duodenum. An open biopsy revealed a bland spindle cell neoplasm. Resection of the tumor was performed. (B) A 68-year-old male presented with an incidental mesenteric mass on imaging during hematuria workup. He underwent surgical resection of the mass to exclude a GIST.

Results
Case A was a 15.0-cm mass arising in gastric antrum, and case B was an 8.0-cm mass arising in antimesenteric side of distal jejunum. Both tumors showed multinodular plexiform growth pattern and foci of cystic changes, with a proliferation of bland spindle cells in a prominent myxoid matrix. Numerous vascular structures were noted without tumor necrosis, nuclear atypia, or mitotic activity. The lesional cells were positive for actin and negative for desmin. The lesional cells were negative for other markers including cytokeratin, CD34, CD117, DOG-1, S-100, and PDGFRA (case B). Both masses were based in the subserosa with focal extension to the muscularis propria in case A. Patient A was followed up for 8 years with no evidence of disease. Patient B was lost to follow-up.

Conclusion
While clinical presentation and imaging finding of PAMT overlap with GIST, PAMT appears to be more indolent. PAMT of distal jejunum has not been previously reported. Small bowel PAMT is much less common than gastric PAMT but can involve variable segments. PAMT may be underdiagnosed.
Refractory Duodenal Ulcer and Upper Gastrointestinal Bleeding Following Yttrium-90 Transarterial Radioembolization
Authors: Dong Yimin , Sun Belinda , Bhattacharyya Achyut 
Published: September 2019

Abstract
Transarterial radioembolization (TARE) with Yttrium-90 (Y90) is widely used for management of primary or secondary liver malignancies that are not amenable to surgery. Nevertheless, complications of Y90 treatment, including rare events of gastric and duodenal ulceration and cirrhosis, may be critical. Here we report a case of a 79-year-old man who received Y90 TARE for metastatic neuroendocrine tumor to liver from bronchial primary and developed multiple iatrogenic GI complications. Following TARE, a gastroduodenal artery (GDA) coil was instituted to prevent migration of Y90 beads. One year following TARE, the patient presented with cirrhosis of unknown etiology, thrombocytopenia, and multiple episodes of upper gastrointestinal bleeding (UGB). Endoscopy demonstrated GDA coil eroding into duodenum through mucosal ulcer base. Three years following TARE, an emergent esophagogastroduodenoscopy was performed due to upper GI bleeding. The histopathologic examination of stomach and duodenum revealed mucosal hemorrhage, submucosal and serosal fibrosis, and chronic inflammation associated with Y90 intravascular beads. A cholecystectomy was performed for fibrotic gallbladder that showed chronic cholecystitis with cholelithiasis and intravascular Y90 beads. GDA coil was removed, which showed attached food material, bacterial colonies, and Candida spp. A subsequent liver biopsy showed previously treated area with Y90 beads, inflammation, and fibrosis in adjacent parenchyma.
Due to rich vascularity, TARE is considered an ideal treatment choice for neuroendocrine tumor. GI ulceration is the most common complication, which occurs in less than 4% patients, and usually can be managed with proton pump inhibitor. A surgery should be performed upon failure of medical treatment. Radiation-associated fibrosis has been reported mainly in hepatocellular carcinoma patients, who often have cirrhosis before the procedure. To conclude, this is the first case report of Y90 TARE complications in multiple GI organs in a metastatic NET patient.