Rare Case of Epitheloid Angiosarcoma Posing a Diagnostic Challenge in Duodenal Biopsy

Abstract

Introduction/Objective Angiosarcoma (AS) is an aggressive tumor usually arising in the skin and soft tissue. We report a unique case of AS presenting as multiple nodules in duodenum with epithelioid histomorphology without prior diagnosis. Methods/Case Report An 80-year-old man presented with dyspnea on exertion, fatigue and severe anemia. Initial work up showed bilateral pleural effusions; a wedge biopsy of the left lung was done, but results were inconclusive. The patient required repeated blood transfusions over the next three months due to persistent anemia, and gastroenterology was consulted to further investigate the cause of anemia. Occult blood was found on rectal examination. Endoscopy revealed multiple mucosal nodules and polyps in the duodenum. Biopsy showed sheets of markedly atypical, lamina propria infiltrating large epithelioid cells with vesicular nuclei, prominent nucleoli, and eosinophilic cytoplasm undermining an adenoma. The atypical cells showed strong positivity for vimentin, CD31 and ERG, patchy positivity for MNF 116; and negative for HHV-8, S-100, CK20, and various other markers. Ki-67 index was approximately 30%. The diagnosis of duodenal angiosarcoma was made and referred for expert consultation, who concurred with the diagnosis. The patient’s previous lung wedge biopsy was reviewed, and determined to represent small foci of metastatic epithelioid angiosarcoma. The patient received radiotherapy but remained dependent on frequent transfusions, and died 7 weeks after the duodenal biopsy. Results (if a Case Study enter NA) NA. Conclusion Angiosarcoma occurring in the GI tract is rare and has a poor prognosis. In our case, the patient presented with an occult GI bleed and was found to have metastatic disease on presentation. AS presenting with epithelioid morphology in the GI tract can cause significant diagnostic challenges; therefore, pathologist should be aware and may benefit from including vascular immunohistochemical markers in work up to rule out this clinically aggressive vascular malignancy.