Abstract
Anaplastic large cell lymphoma (ALCL) is a rare subtype of non-Hodgkin lymphoma (NHL). Primary gastric anaplastic lymphoma kinase (ALK) negative ALCL is extremely rare. Diagnosis of primary gastric ALK-negative ALCL is difficult to establish and prognosis is worse than ALK-positive ALCL. Here, we report a case of an 82-year-old man with a history of cerebrovascular disease presented with weakness and iron deficiency anemia. He denied any abdominal discomforts. The esophagogastroduodenoscopy revealed a large ulcerated, friable mass in the gastric body which encompassed about 80% of entire stomach. Biopsy showed a high grade malignant tumor composed of undifferentiated epithelioid atypical cells, making it difficult to determine the cell of origin. Immunostains for lymphoma, carcinoma, and sarcoma were performed. The tumor cells were positive for CD30, CD4, and CD43, negative for CD20, CD3, ALK-1 and Epstein-Barr virus (EBV)-encoded small RNAs (EBERs) in situ hybridization, establishing the diagnosis of primary gastric ALK-negative ALCL. The patient is currently undergoing chemotherapy with clinical improvement. To the best of our knowledge, this is the first reported case of primary gastric ALK-negative and EBV-negative anaplastic large T-cell lymphoma that presented without gastroenterological symptoms.