Signet-ring cell adenocarcinoma of unknown primary presenting with superior vena cava (SVC) syndrome: rare type of cancer.

A 53-year-old man presented with a 3-month history of progressive, non-productive cough followed by occasional swelling of the face and upper extremities. Physical examination on admission revealed prominent superficial vessels at the neck and upper extremity swelling. Bronchoscopy revealed the superior segment of the right lower lobe was narrow but without visible mass; cell block and biopsy done revealed signet-ring cell carcinoma with an immunohistochemistry pattern favouring the primary site of malignancy as either gastric or of the pancreaticobiliary tree. However, CT scan of the abdomen and pelvis with triple contrast revealed only slight gastric wall thickening; the pancreas was unremarkable. The patient underwent radiotherapy with noted improvement of symptoms. He was then discharged with plans for further work-up on an outpatient basis. This work highlights the importance of a comprehensive histopathological and immunohistochemical work-up which can help predict a site of origin to be able to provide the appropriate management.
Competing Interests: Competing interests: None declared.
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