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* Context.--Molecular analysis of poorly differentiated/ undifferentiated sinonasal neoplasms has resulted in identification of a growing number of genetically defined tumors. SMARCA4-deficient sinonasal carcinoma is one such recently described entity that emerged from within sinonasal undifferentiated carcinoma (SNUC), neuroendocrine carcinoma (NEC), and teratocarcinosarcoma (TCS). Objective.--To identify SMARCA4-deficient sinonasal carcinomas from a large institutional cohort of poorly differentiated/undifferentiated carcinomas and evaluate their clinicopathologic features. Design.--SMARCA4/BRG1 immunohistochemistry was performed on all tumors diagnosed as SNUC, poorly differentiated carcinoma, NEC, and TCS during a 12-year period. SMARCA2/BRM and INSM1 immunostaining was performed in SMARCA4-deficient cases. Results.--Twelve SMARCA4-deficient sinonasal carcinomas were identified among 299 cases. Morphologically, 5 cases were large cell NEC, 2 cases were small cell NEC, and 5 were TCS. SMARCA4 loss was diffuse and complete in 10 cases, while 2 cases showed focal retention. Most cases showed diffuse cytokeratin staining accompanied by weak, usually focal staining for chromogranin and synaptophysin. INSM-1 showed negativity in most cases. All cases showed retained SMARCA2 expression. IDH1/2 mutation was absent in all cases analyzed. Four of 7 patients died of disease, and aggressive multimodality treatment provided better outcome. Conclusions.--SMARCA4-deficient sinonasal carcinomas are morphologically akin to sinonasal poorly differentiated NECs and TCS, display cytokeratin positivity and only focal staining for neuroendocrine markers, and have aggressive biological behavior. Inclusion of SMARCA4 in the immunohistochemical panel for diagnostic workup of all sinonasal NEC and TCS phenotypes will facilitate their early recognition. Comprehensive germline and somatic mutational analyses of these tumors are necessary for further insights into their molecular pathogenesis. (Arch Pathol Lab Med. 2022;146:1122-1130; doi: 10.5858/arpa.2021-0001-OA), The sinonasal tract harbors a diverse spectrum of high-grade neoplasms, many of which have considerable overlapping morphologic features owing to their poorly differentiated or undifferentiated appearance. (1,2) Some of these [...]

Carotid body tumors are slow growing neck masses that arise from the neural crest cells at the carotid bifurcation. Majority are asymptomatic and are diagnosed incidentally. Surgical excision is accepted as the treatment of choice to reduce complications. In the present series, we report 10 cases of carotid body tumors and our institutional experience. All patients underwent radiological evaluation with an ultrasonography with Doppler, contrast enhanced computed tomography and MR angiography. 6 cases were operated by a transcervical excision. The tumor was excised in tototranscervically. One of the cases required saphenous vein graft intraoperatively due to vascular injury and also had postoperative vocal cord palsy. The rest had an uneventful recovery. Carotid body tumors although rare and seemingly indolent can cause substantial symptoms if left untreated. A prompt multi modality approach is needed for both diagnosis and treatment to avoid major complications. [ABSTRACT FROM AUTHOR]

Introduction: Acinar cystic transformation (ACT) of the pancreas is characterized by multiple cysts lined by dual ductal and acinar-type of epithelium. ACT is typically a disease of adulthood and has not been described in a neonate. Case report: Autopsy of this term 3-day old male demonstrated cystic transformation of the entire pancreas measuring 42 mm in its largest dimension. The main pancreatic duct was patent. The numerous variable-sized cysts were lined by both ductal (CK7-positive) and acinar (trypsin-positive) epithelium. Congenital hemochromatosis of the liver, complete proximal jejunal atresia, gangrene of the post-atretic jejunum, and subglottic stenosis were associated features. Discussion/Conclusion: ACT may occur in the neonate in association with other abnormalities. [ABSTRACT FROM AUTHOR]

Myocardial perfusion imaging (MPI) is primarily done to look for stress induced perfusion defects in patients suspected of coronary artery disease. However, the rotating raw images can provide a significant information regarding surrounding structures. The lungs lie in close proximity to heart and any abnormality showing increased uptake can be seen on MPI. We report a case of 52-year-old man, with history of diabates for last 5 years, who presented to cardiac outpatient department (OPD) for occasional chest pain and dyspnea. Electrocardiogram (ECG) and echocardiography showed no significant abnormality. Patient was referred to nuclear medicine department for stress induced myocardial perfusion scintigraphy. The raw 99m-Tc sestamibi images were showing abnormal uptake in right lung hilar region which on subsequent investigations was diagnosed as a case of atypical bronchial carcinoid tumor. [ABSTRACT FROM AUTHOR]

Malignant gastrointestinal (GI) neuroectodermal tumor is an extremely rare entity that was first described by Zambrano et al. in 2003 as "clear cell sarcoma (CCS)-like tumor of the GI tract." It shares some of the histopathological features of CCS but lacks the immunohistochemical (IHC) reactivity for melanocytic markers. Most mesenchymal neoplasms of the GI tract belong to the category of GI stromal tumors and are characterized by the IHC expression of c-KIT. In cases, without detectable KIT receptor expression, several differential diagnoses have to be taken into consideration. In this article, we describe such a case and present a review of all the reported cases till date. We also present the current available knowledge on its pathology and molecular genetics along with the limitations in its diagnosis. Here, we report a case of a 32-year-old man with a tumor of the small bowel composed of polygonal tumor cells arranged in solid nests, alveolar pattern, and pseudopapillary and admixed with numerous osteoclast-like multinucleated giant cells. Immunohistochemically, the tumor cells strongly expressed S-100 protein only. HMB-45, melan-A, CD117, cytokeratin, desmin, smooth muscle actin, and CD-34 were absent. Ki-67 index was 15%. The diagnosis was further confirmed by fluorescence in situ hybridization (FISH) demonstrating the presence of EWSR1 (22q12) translocation. A final diagnosis of malignant gastroneuroectodermal tumor was rendered. The patient is disease-free for 20 months of postsurgery. The diagnosis of this entity should be considered in the presence of S-100-positivity and multinucleated osteoclastic giant cells and the absence of melanocytic differentiation in a tumor arising from GI tract. Further confirmation can be done by performing FISH analysis. [ABSTRACT FROM AUTHOR]

A case of signet ring cell lymphoma of presacral lymph node is reported. The patient was diagnosed as follicular lymphoma on the basis of clinical and laboratory features, including immunohistochemistry (IHC) and gene rearrangement studies. Light microscopy examination showed neoplastic atypical cells with signet ring cell morphology in core biopsy of lymph node that stained for B-cell markers by IHC. In addition, the neoplastic cells expressed CD20, CD10, BCL-2, and BCL-6, indicating follicular center origin. Fluorescence in situ hybridization study demonstrated BCL2 gene arrangement. Especially in the case of deep-seated intra-abdominal lymph nodes with atypical presentation, the differential diagnosis arises with nonhemopoietic tumors, and this needs to be distinguished by specific immunostaining and gene arrangement studies. [ABSTRACT FROM AUTHOR]

Diagnosis of a high grade neuroendocrine carcinoma may be difficult in fluid cytology. Although, based on its nuclear atypia, it is easy to identify the cells as malignant, it is difficult to classify them beyond malignancy. Immunohistochemistry on cell blocks can help in making the proper diagnosis. [ABSTRACT FROM AUTHOR]