SIGNET-RING CELL CARCINOMA OF UNKNOWN PRIMARY: A CASE REPORT AND REVIEW OF RELATED LITERATURE OF A RARE TYPE OF CANCER WITH A RARE PRESENTATION

Abstract

PURPOSE: We report a case of metastatic signet-ring cell carcinoma (SRRC) of unknown primary presenting with superior vena cava syndrome and discuss our approach to diagnosis and management. METHODS: Case report and review of literature. RESULTS: A 53-year-old man, non-smoker, presented with a three-month history of worsening non-productive cough, upper back pain and facial and bilateral upper extremity swelling. On admission, he had a blood pressure of 180/100 mmHg, facial puffiness, neck vein engorgement, absent breath sounds with decreased vocal fremitus over the right lower lung and swelling of bilateral upper extremities. Work-up done revealed the following: (a) chest CT scan:right para-tracheal and hilar mass compressing the superior vena cava and bilateral pleural effusion; (b) fiberoptic bronchoscopy:extrinsic compression of the right lower lobe - superior lung segment; (c) pleural fluid and bronchoalveolar lavage histopathology:consistent with metastatic adenocarcinoma (SRCC subtype – positive for CK7, negative for CK 20, TTF-1, and calretinin), favoring a gastric or pancreaticobiliary primary; (d) abdominopelvic CT scan:slight fundic wall thickening and normal pancreas and bile duct; multiple scattered metastatic foci were noted. CONCLUSIONS: He gradually improved with radiotherapy and intravenous steroids. Out-patient chemotherapy was then planned. CLINICAL IMPLICATIONS: SRCC is an aggressive type of poorly differentiated adenocarcinoma with superior vena cava syndrome as a rare initial manifestation. Determining the primary site remains priority and is paramount in guiding further management. However, current evidences have mainly focused on palliative chemotherapy as treatment of choice in most cases.