bluuebunny/crossref_metadata_2025_split huggingface dataset:
Malignant Peripheral Nerve Sheath Tumor of the Pancreas with Molecular Confirmation: A Case Report with Comprehensive Histopathologic and Molecular Characterization
Authors: Chitsaz M , Kaufman T , Macaulay R , Henderson-Jackson E , Nakanishi Y 
Published: October 2024

Abstract

Introduction/Objective
Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue sarcomas arising from a peripheral nerve or exhibiting nerve sheath differentiation. They are often associated with neurofibromatosis type 1, and most often arise in the trunk, extremities, or head and neck region. In patients without neurofibromatosis type 1, sporadic de novo or radiotherapy-associated MPNSTs can pose a diagnostic challenge. MPNSTs arising from visceral organs are exceedingly rare. Here we report a case of MPNST arising in the pancreas.

Methods/Case Report
The patient is a 75-year-old female, MUTYH mutation carrier, with prior history of breast and bladder cancers, each treated with respective local excision and radiation therapy. Magnetic resonance imaging (MRI) performed for pancreatic cancer screening showed a 4.7 cm heterogeneous mass in the pancreatic tail suggestive of pancreatic neoplasm. Fine needle aspiration cytology was non-diagnostic. However, due to the radiologic concern for malignancy, the patient proceeded with surgical resection by distal pancreatectomy with splenectomy.
Macroscopically, a 6.5 cm, tan-white, partially necrotic mass was identified in the pancreatic tail. Microscopic examination showed a spindle cell neoplasm arranged in a vague fascicular fashion with moderate nuclear pleomorphism, geographic necrosis, and frequent mitotic figures (15 per 10 high power fields). Fifteen lymph nodes were negative for metastasis. The tumor was confined to the pancreas grossly and microscopically.
Immunohistochemical stains showed the neoplastic spindle cells to be positive for TLE1 (diffuse) and S100 (patchy), while negative for SOX10, CD117, DOG1, desmin, actin, MyoD1, ERG, STAT6, and ALK1. In addition, H3K27me3 showed loss of nuclear expression. Next generation sequencing (NGS) revealed gene mutations in NF1, TP53, PIK3CA, and PTEN, and copy number losses involving CDKN2A and CDKN2B. Genome-wide DNA methylation analysis was performed which revealed copy number losses of CDKN2A/B and gains of PTCH1 and MDM2. However, the Sarcoma DNA Methylation Classifier did not provide any diagnostic matches. Overall, the morphologic features, loss of H3K27me3 expression, presence of NF1 and TP53 mutations, and copy number losses in CDKN2A/B supported a diagnosis of high-grade MPNST. The patient has been followed clinically without adjuvant therapy.

Results (if a Case Study enter NA)
N/A

Conclusion
We report an extremely rare case of MPNST of the pancreas with molecular confirmation.
Congenital Appendiceal Atresia: An Extremely Rare Disorder Presenting with Acute Abdomen
Authors: Asad M , ANAND S , Sieber S C 
Published: October 2024

Abstract

Introduction/Objective
Congenital malformations of the appendix are extremely rare and difficult to diagnose preoperatively. One of those anomalies include congenital appendiceal atresia (CAA) which mimics acute appendicitis and is usually ignored in the differentials of acute abdomen. Herein, we present a case study of congenital appendiceal atresia associated with periappendicitis.

Methods/Case Report
A 62-year-old female with past history of diverticulitis presented with complaints of crampy, diffuse and progressive lower abdominal pain and nausea for two days. She denied fevers, chills or change in bowel movements. Physical examination revealed vitally stable patient with soft, non-distended and tender abdomen in bilateral lower quadrants, worse on the right side and showing positive rebound test. Her complete blood count and chemistry were within normal limits. A computerized tomography arterial portography (CTAP) scan with contrast demonstrated inflammatory stranding around the appendix without abscess, concerning for acute appendicitis. She then underwent laparoscopic appendectomy. Grossly, the appendix consisted of a cylindrical portion of yellow-pink fatty tissue covered by peritoneum measuring 6.2 x 3.3 x 0.5 cm. The peritoneal surface displayed patchy fibrinous exudates. Sectioning revealed yellow adipose tissue with no identifiable appendix. Microscopically, the entire specimen demonstrated a poorly formed, mainly fatty appendix without a discernible lumen or submucosal lymphoid tissue. There were scattered sparsely distributed non-continuous bundles of smooth muscle (muscularis propria) at the periphery, which were highlighted by desmin and trichrome stains. This atretic appendix, mesoappendix and peritoneal covering were acutely inflamed. The final diagnosis was poorly formed, acutely inflamed fatty appendix consistent with congenital appendiceal atresia with accompanying acute periappendicitis.

Results (if a Case Study enter NA)
NA

Conclusion
This case would add to the very limited existing literature for congenital appendiceal anomalies and highlight the importance of thorough surgical intraoperative abdominal exploration and submission of the entire specimen for microscopic examination in order to render a definitive diagnosis.
A 34-year-old woman with mucolipidosis type IV predisposing to a neuroendocrine tumor in the gastric fundus
Authors: Snow M , del Portillo A 
Published: October 2024

Abstract

Introduction/Objective
Mucolipidosis type IV (MLIV) is a lysosomal storage disorder with a gastric phenotype. Patients develop achlorhydia and compensatory hypergastrinemia, with pathology showing vacuolated parietal cells with lysosomal inclusions. MLIV is caused by mutation of TRPML1, a lysosomal membrane calcium channel required for trafficking proton pumps to the apical surface in parietal cells. We report the first case of MLIV predisposing to a neuroendocrine tumor (NET). This novel finding could impact management of patients with this disease, who may require frequent monitoring for NETs. We also show that immunohistochemistry for TRPML1 and H+/K+ ATPase can be used in conjunction to identify gastric MLIV. We hope that our updated immunohistochemical tools can aid in diagnosis of this disease.

Methods/Case Report
34-year-old woman with MLIV requiring endoscopic resection for an incidentally discovered gastric polyp. Pathology showed Grade 2 NET invasion into submucosa (pT1). Background mucosa showed markedly vacuolated parietal cells, ranging from unilocular to multilocular with up to 20 vacuoles per cell. We stained the patient’s and a control stomach with antibodies against the TRPML1 and H+/K+ ATPase proteins. The H+/K+ ATPase antibody highlighted healthy parietal cells in the control stomach with strong cytoplasmic signal, but strikingly outlined lysosomal inclusions in MLIV parietal cells. TRPML-1 antibody showed cytoplasmic staining in parietal cells in the control. However, TRPML-1 staining showed markedly decreased signal in the patient and nuclear staining, possibly representing mislocalization.

Results (if a Case Study enter NA)
NA

Conclusion
We present the first case of MLIV predisposing to a NET in the stomach. NETs have potential for metastatic spread with subsequent mortality risk. Clinicians should maintain suspicion for NET development in this population, and protocols for frequent surveillance should be considered.
This is also the first report using immunohistochemistry for TRPML1 and H+/K+ ATPase in combination to identify affected parietal cells in MLIV. Possibly, these tools can be used in the future by pathologists to diagnose MLIV.
Duodenal Adenocarcinoma Arising from Brunner’s Glands, A Rare Case Report
Authors: Arumugam S 
Published: October 2024

Abstract

Introduction/Objective
Malignancies arising from the Brunner’s glands in duodenum are exceedingly rare with very few cases reported in the literature. Here, we reported a case of duodenal adenocarcinoma of Brunner’s gland origin that obstructed duodenum and extended to involve the pancreatic head.

Methods/Case Report
A 48-year-old woman came to the Emergency Department of our hospital with epigastric and right upper quadrant abdominal pain. CT imaging demonstrated a heterogeneously enhancing 8.4 x 5.4 x 6 cm mass involving the duodenal lumen, wall, and pancreatic head. An endoscopic ultrasound showed a large fungating, infiltrative, and ulcerative mass in the second portion of the duodenum distal to the ampulla but not involving it. The pancreatic and common bile ducts were uninvolved. Her endoscopic ultrasound biopsy was positive for adenocarcinoma. CA19-9 levels were normal. The patient received chemotherapy with subsequent Whipple procedure. Gross examination revealed an exophytic, tan-white mass with the epicenter in the duodenal wall obstructing the duodenal lumen and extending to involve the pancreatic head inferiorly. The mass was predominantly solid with a few small mucus cysts. Light microscopy demonstrated moderately differentiated adenocarcinoma with prominent necrosis and inflammation. There are intestinal-type, gastric-type and indeterminate types of epithelia in the carcinoma. There are areas in the duodenal wall where a continuous transition from benign Brunner’s glands to dysplastic glands and then to adenocarcinoma is present. Neither adenoma in the overlying duodenal mucosa nor abnormalities in the pancreatic parenchyma is observed. Immunohistochemical stains showed that the neoplastic cells are positive for CAM 5.2, AE1/AE3, and CK7, while only patchy positivity with CK20 and CDX2. Taken together, a diagnosis of duodenal adenocarcinoma arising from Brunner’s glands was rendered.

Results (if a Case Study enter NA)
N/A

Conclusion
More cases are needed in order to establish standard treatment guidelines and determine prognostic factors.
Leiomyomas of the Gastrointestinal Tract: A Clinicopathologic Review
Authors: Apdik T , Musharraf S , Gattuso P , Reddy V , Cheng L , Furci F 
Published: October 2024

Abstract

Introduction/Objective
Leiomyomas are benign smooth muscle tumors that can be found anywhere along the gastrointestinal tract (GIT). We undertook a retrospective study to investigate the incidence of GIT leiomyomas and to gain better understanding of their clinicopathologic characteristics.

Methods/Case Report
The surgical pathology files at our institution were searched for GIT leiomyomas encountered between 07/1994 and 12/2023. The clinical and histopathological findings were recorded.

Results (if a Case Study enter NA)
74 leiomyomas were identified in various GIT locations, including esophagus (8), stomach (20), duodenum (3), colon (37) and rectum (6). There were 40 females and 34 males, with an average age of 61.5 years.
Esophageal leiomyomas showed a mean size of 2.2 cm. 5/8 patients had synchronous adenocarcinomas of gastroesophageal junction and 1/8 patient had synchronous squamous cell carcinoma of esophagus.
Gastric leiomyomas showed a mean size of 2.0 cm. 6/20 patients had synchronous and 4/20 patients had metachronous GIT cancers. 2/6 patients who had leiomyomas with synchronous GIT cancers also presented with gastrointestinal stromal tumors (GIST).
Duodenal leiomyomas showed a mean size of 0.7 cm. 1/3 patient had synchronous pancreatic adenocarcinoma. Colonic leiomyomas showed a mean tumor size of 0.6 cm. 2/37 patients had synchronous and 6/37 patients had metachronous GIT cancers.
Rectal leiomyomas showed a mean tumor size of 0.9 cm. 1/6 patient had metachronous non-GIT sarcoma. Adenomatous polyps coexisted with 10/37 colonic leiomyomas, 2/6 rectal leiomyomas and 1/20 gastric leiomyoma. Immunohistochemical stains (αSMA, Desmin, CD117, DOG-1, CD34) were consistently utilized in diagnosis to exclude GIST.

Conclusion
Leiomyomas were most frequently found in the colon (50.0%), followed by the stomach (27.0%). Esophageal and gastric leiomyomas showed larger sizes (averaged 2.2 and 2.0 cm respectively) than duodenal, colonic, and rectal counterparts (averaged 0.7, 0.6, and 1 cm, respectively). This suggests an association between tumor locations and clinical features.
Synchronous malignancies occurred in 20.2% of cases, mainly gastroesophageal/colonic adenocarcinomas. Metachronous malignancies were noted in 14.8% of cases. Given the high incidence of synchronous/metachronous malignancies (35.1%) in the gastrointestinal tract, close clinical surveillance is warranted for these patients.
Mediastinal Teratoma with Angiosarcomatous Overgrowth in a Background of Vasculogenic Mesenchymal Tumor
Authors: Graham S M , Pham J M , Cao T , Hamza A 
Published: October 2024

Abstract

Introduction/Objective
Vasculogenic mesenchymal tumor refers to neoplastic reiteration of embryonic vasculogenesis. It is most commonly associated with nonseminomatous germ cell tumors of the mediastinum, in particular yolk sac tumor. In rare instances these lesions progress to angiosarcoma. Herein, we describe a case of angiosarcoma in a background of vasculogenic mesenchymal tumor in the setting of a mediastinal teratoma.

Methods/Case Report
A 33-year-old male, with a past medical history of anxiety, and right orchiectomy for testicular torsion, presented with shortness of breath, chest pain, and left arm swelling. Imaging studies demonstrated a mediastinal mass. Biopsy of the mass showed a germ cell tumor most compatible with a teratoma in the limited specimen. The patient received two rounds of chemotherapy and additional treatments were discontinued due to poor tolerance. Subsequent imaging showed continued increase in the size along with mass effect causing moderate to severe compression of the superior vena cava. Subsequently, the patient underwent resection of the mass. Grossly the mass was predominantly encapsulated with areas of capsular disruption. Sectioning revealed heterogeneous cut surfaces with fleshy, cystic, and necrotic areas. Morphologically the tumor was composed predominantly of teratomatous elements with areas of anastomosing atypical vascular channels within a hypocellular stroma suggestive of vascular genic mesenchymal as well as areas reminiscent of Masson lesion. Focally within these areas were malignant spindle cell proliferations compatible with angiosarcoma. The patient had an elevated AFP; however, no yolk sac tumor component was identified after thorough sampling. Final diagnosis of teratoma with angiosarcoma in a background of vasculogenic mesenchymal tumor was rendered after expert consultation.

Results (if a Case Study enter NA)
NA

Conclusion
Somatic-type malignancy and sarcomatous overgrowth are known to occur in mediastinal germ cell tumors; however, classification of the sarcomatous overgrowth can be challenging. Vasculogenic mesenchymal tumor is an exceedingly rare sarcomatous overgrowth that can rarely progress to angiosarcoma.
Weakly supervised deep learning for diagnosis of prostate cancer after radical prostatectomy: a population- based, multicenter study
Authors: Xiao Y , Mai Z , Yan W 
Published: October 2024

Abstract

Introduction/Objective
The pathological diagnosis of prostate cancer after radical prostatectomy (RP) is a challenging and time-consuming process. Artificial intelligence has the potential to enhance this situation significantly. Our study aimed to assess the efficacy of weakly supervised deep learning, specifically focusing on practical diagnostic tasks for RP specimens.

Methods/Case Report
We obtained slices from clinical centers across four regions in China. The model was developed based on a multiple instance learning framework. We evaluated the model’s predictive accuracy, covering both slice-level and lesion-level diagnoses. Additionally, we investigated lesion localization using attention visualization. Slice-level diagnosis included prostate cancer detection and Gleason grading, while lesion-level diagnosis involved recognizing index lesions and non-index lesions.

Results (if a Case Study enter NA)
The study involved 13,245 slides from 304 patients. The area under the curve values in four validation sets ranged from 0.921 (95% CI 0.913–0.930) to 0.964 (95% CI 0.959–0.968). Regarding Gleason grading, the model demonstrated quadratic Weighted Kappa values of 0.748 and 0.720 for internal and external validation, respectively. The model predicted 1,683 (35.3%) positive and 3,081 (64.7%) negative slices in all validation sets. The median area of index lesions and non-index lesions was 92.6mm2 (IQR: 54.2–130.0mm2) and 3.5mm2 (IQR: 1.4–10.9mm2) (p&lt;0.001), respectively. The model accurately predicted index lesions in all cases for three validation sets. Furthermore, the model achieved 100% accuracy in predicting slides with the maximum tumor area for index lesions in two validation sets. In visual assessment, 200 randomly selected slices predicted as true positive demonstrated that the model could identify 97.5% (195/200) of the index lesions.

Conclusion
The weakly supervised deep learning model demonstrated remarkably high diagnostic and localization capabilities in identifying index lesions within RP specimens. This targeted approach would effectively alleviate the diagnostic workload associated with pathology assessments for prostate cancer.
Leiomyoma with bizarre nuclei occurring post hysterectomy mimicking malignancy: a rare case report
Authors: Bian F , Feng Y , Angel J 
Published: October 2024

Abstract

Introduction/Objective
Leiomyoma with bizarre nuclei (LBN), also known as symplastic leiomyoma, represents a rare subtype of benign uterine smooth muscle neoplasm. Histologically, it is characterized by significant cytological atypia in a typical leiomyoma background with rare mitoses and without tumor necrosis.

Methods/Case Report
We report a case of a 48-year-old woman, status post hysterectomy for symptomatic fibroids, with imaging showing multiple contiguous pelvic masses extending from the pelvis to the upper abdomen and displacing the colon laterally and small bowel posteriorly. The findings were highly suspicious for ovarian malignancy. A bilateral salpingo-oophorectomy and a partial colectomy were performed with tumor debulking and omentectomy. Grossly, multiple well-circumscribed soft masses ranging in size from 1.5-16 cm, in contiguity with pericolonic mesentery with a smooth fleshy cut surface and cystic changes were found. Bilateral ovaries were unremarkable.
Microscopically the larger masses were composed of spindle cells with bizarre nuclei throughout, while smaller masses showed foci of bizarrely shaped-spindle cells with bizarre nuclei in a background of a typical leiomyoma. Mono- and multinucleated cells with smudged chromatin were also seen. The mitotic index was low confirmed with a low Ki-67 proliferation index (&lt; 5%). Immunohistochemical stainings showed that the neoplastic cells were positive for desmin, SMA, and caldesmon; and negative for CD10, with a wild type p53 expression. Fumarate hydratase immunostain was retained. MDM2 amplification was not detected by FISH. The morphology and immunohistochemical findings were compatible with LBN.

Results (if a Case Study enter NA)
NA

Conclusion
In summary, this is a rare and challenging case of multiple LBN developed years post hysterectomy and clinically mimicking a malignancy.
Rare Presentation of Anaplastic Carcinoma as a Mural Nodule in Mucinous Cystadenoma with Concurrent Benign Brenner Tumor
Authors: Poombal F , Noor R , Pervaiz J , Khalid F , Zaman S 
Published: October 2024

Abstract

Introduction/Objective
Mural nodules in ovarian mucinous tumors, particularly which are anaplastic carcinomas, represent an exceedingly rare and complex diagnostic category. The literature documents only a few such tumors, predominantly sarcoma-like, with favorable prognoses. In contrast, malignant mural nodules, including anaplastic carcinoma and sarcomatous or carcinosarcomatous types, are notably rare, with fewer than ten cases reported. The co-occurrence of an anaplastic carcinoma mural nodule with a benign Brenner tumor presents distinct diagnostic and treatment complexities stemming from mixed tumor pathology and associated genetic mutations like KRAS and p53, critical in the development of these unusual nodules. This report deepens our insight into rare ovarian tumors.

Methods/Case Report
A 60-year-old woman with persistent lower abdominal pain underwent surgery for a suspected benign ovarian cyst based on initial imaging. The removed ovary contained a 10.5 x 10 x 8 cm unilocular cyst lined with benign, mucin-containing columnar epithelium. However, a 2 cm anaplastic carcinoma mural nodule was identified within the cyst, exhibiting cellular pleomorphism, nuclear atypia, and high mitotic activity.
Immunohistochemical staining confirmed the carcinoma with diffuse cytokeratin and EMA positivity. The fallopian tube was free of tumor involvement, and no capsular or lymphovascular invasion was seen. The cancer was staged as PT1a, pNx, pMx.

Results (if a Case Study enter NA)
NA

Conclusion
Anaplastic carcinoma, when present as a mural nodule within a benign-looking mucinous cystadenoma, demands an aggressive treatment strategy due to its poor prognosis and aggressive nature. Such cases require a deviation from standard benign treatment protocols to include extensive surgery, possibly, depending on disease progression, chemotherapy or radiation.
All that is squamoid is not squamous: A rare case of Squamoid Eccrine Ductal Carcinoma presenting as an intranasal mass
Authors: Sakaleshpura Mallikarjuna V , Nani C , Hagen M , Sharma D , Gilday S 
Published: October 2024

Abstract

Introduction/Objective
Squamoid eccrine ductal carcinoma (SEDC) is a rare adnexal tumor that poses diagnostic challenges because of the rarity, variable clinical presentation, and misdiagnosis on superficial biopsy sampling.

Methods/Case Report
We report a 52-year-old immunosuppressed male, status-post kidney and heart transplants who presented with an anterior nasal mass, the biopsy of which was interpreted as squamous cell carcinoma (SCC). Resection revealed a 2.5cm intranasal mass eroding through the hard palate. Histology showed a biphasic tumor arising from nasal vestibular skin with a superficial squamoid component (p40 positive) and a deeply invasive component demonstrating ductal differentiation (CEA positive) consistent with SEDC. SEDC has a predilection towards skin of head and neck region but SEDC presenting as an intranasal mass has not been reported. In our case, the tumor arose from nasal vestibular skin with destructive bony invasion within the nasal cavity. The patient’s long- term immunosuppression likely played a role in the etiopathogenesis and aggressive progression of this tumor.
Interestingly, he also had history of multiple sebaceous carcinomas and cutaneous T-cell lymphoma with no known genetic predisposition, further implicating immunosuppression as the key risk factor for development of his cutaneous malignances.

Results (if a Case Study enter NA)
N/A

Conclusion
This case exemplifies the potential diagnostic pitfalls in squamoid lesions of the head and neck. Given the overwhelming prevalence of conventional SCC, rarer tumors with squamous differentiation often are not considered in the differential diagnosis, especially of an intranasal mass. A superficial biopsy often is misdiagnosed as SCC due to the lack of representation of deep-seated ductal components. A high index of suspicion and adequate examination of deeper aspects of the lesion are imperative for accurate diagnosis.