Gangliocytic Paraganglioma: A Rare Etiology of Obstructive Jaundice.

BACKGROUND Gangliocytic paraganglioma is an extremely rare tumor, with only 263 reported cases. This tumor has heterogeneous clinical presentation, with gastrointestinal bleeding being the most common. However, jaundice is a relatively unusual presentation, seen in less than 5% of all cases. CASE REPORT We report the case of a 32-year-old man who presented with abdominal pain and jaundice. He reported having similar episodes of this pain recently, but they were milder in severity. On examination, there was a tenderness in the right upper quadrant with a positive Murphy sign. Laboratory investigation revealed total bilirubin of 3.6 mg/dL with a direct bilirubin of 3.0 mg/dL, alkaline phosphatase of 323 IU/L, and g-glutamyltransferase level of 1153 IU/L, giving the impression of obstructive jaundice. The abdominal ultrasound examination revealed a normal common bile duct diameter with no thickening or pericholecystic fluid noted. Subsequently, the patient underwent endoscopic retrograde cholangiopancreatography, which revealed a mass in the second part of the duodenum. Histopathological examination of biopsy specimens obtained by fine-needle biopsy revealed an unencapsulated submucosal lesion with epithelioid, spindle, and ganglion cells. The spindle cells expressed positive immunohistochemical staining for S100, synaptophysin, and chromogranin. These findings were consistent with the diagnosis of gangliocytic paraganglioma. Surgical resection of the tumor was advised. However, the patient refused the operation despite the recommendation of the oncology team. CONCLUSIONS Gangliocytic paraganglioma is a very rare tumor that may present with a clinical picture mimicking a biliary disease. Clinicians should have a high index of suspicion for duodenal lesions in patients presenting with obstructive jaundice with no evidence of biliary stones.

Primary paranasal sinus hyalinizing clear cell carcinoma: a case report.

BACKGROUND: Hyalinizing clear cell carcinoma (HCCC) is a rare low-grade tumour of salivary glands that was first described as a distinct entity in 1994 by Milchgrub et al. EWSR1-ATF1 fusion was found to be specific for this tumour. The majority of the reported cases of HCCC arise from minor salivary glands within the oral cavity. Primary HCCC of the paranasal sinus is extremely uncommon. To our knowledge, only three cases have been reported in the English literature. Herein, we present a case of HCCC of the posterior ethmoid/maxillary sinus. CASE PRESENTATION: A 63-year-old lady who presented with a long history of epistaxis. CT scan revealed a destructive mass in the left ethmoid/posterior maxillary sinus extending to the nasal cavity. Surgical excision was done and microscopic evaluation showed a tumour composed mainly of nests of clear epithelial cells separated by fibrocellular and hyalinized septa with extensive bone destruction. The tumour cells expressed CK5/6, EMA and p63 immunohistochemically but were negative for S100 protein, PAX-8, RCC and CK7. Sinonasal renal cell-like adenocarcinomas, myoepithelial carcinoma and metastatic renal cell carcinoma were excluded by radiological and immunohistochemical studies. Fluorescence in situ hybridization analysis revealed an EWSR1 gene rearrangement. Postoperative radiation was administrated and the patient did not show recurrence or distant metastasis 4 months after the surgery. CONCLUSION: Head and neck region have many tumours that demonstrate clear cell changes on histology. Thus, the differential diagnosis for HCCC is wide. Awareness of this rare entity and the possibility of it is arising in unusual location is necessary. EWSR1-AFT1 fusion, a consistent finding in HCCC, can be used to confirm the diagnosis.

Malignant gastrointestinal neuroectodermal tumor: a case report and review of the literature.

BACKGROUND: Malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare entity that was first described by Zambrano et al. in 2003 as "Clear cell sarcoma-like tumor of the gastrointestinal tract". It shares some of the histological features of clear cell sarcoma (CCS) but lacks the immunohistochemical reactivity for melanocytic markers. We report a case of GNET that was initially misdiagnosed as gastrointestinal stromal tumor (GIST). Recognizing this entity is important to avoid misdiagnosis. CASE PRESENTATION: A case of an 18-year-old male presented with a small intestinal tumor. Histologically it was characterized by polygonal cells arranged in pseudoalveolar pattern and situated in the muscularis propria. Scattered osteoclast-like multinucleated giant cells were also noted. The neoplastic cells were positive for S-100 protein and negative for HMB-45, Melan A, smooth muscle actin, desmin and CD117. EWSR1 gene rearrangement was detected by fluorescence in situ hybridization (FISH) analysis. The patient returned with recurrence after 36 months' management by surgical resection and died one year later. CONCLUSIONS: GNET can be mistaken histologically for other non-epithelial gastrointestinal tumors. Awareness of its existence and diagnostic criteria by the pathologist is necessary to avoid misdiagnosis, particularly as GIST, CCS or malignant peripheral nerve sheath tumor (MPNST).