A rare cause of intestinal obstruction: jejunal ALK positive anaplastic large-cell lymphoma.

A 32-year-old man had recurrent abdominal pain and vomiting for 2 weeks. Physical examination revealed a 4×2-cm abdominal tough mass with unclear boundaries. Palpation caused mild tenderness without rebound pain. Computed tomography (CT) showed a proximal jejunal mass with incomplete small-bowel obstruction , and double-balloon enteroscopy showed a large protruding proximal jejunal mass covered with dirt and a narrow lumen ; an enteroscope would not pass through. Pathological diagnosis by insufficiently deep endoscopic biopsy is difficult. After multidisciplinary discussion, surgical resection was performed. Histopathology revealed a malignant tumor . Immunohistochemical results: CD30 (+), ALK (+), EMA (+), GrB (+), CD2 (+), CD43 (+), TIA-1 (+), and silver staining (+). Sarcoma 86 fusion-gene detection showed NPM1-ALK gene rearrangement. The patient was diagnosed with anaplastic large-cell lymphoma (ALCL) and underwent chemotherapy.