Extramedullary Plasmacytoma of the Small Intestine: A Case Report

Extramedullary plasmacytoma (EMP) of the gastrointestinal tract is an uncommon-type of neoplasms. This report describes a case of EMP in the small intestine. A 78-year-old male, with abdominal discomfort and vomiting, was found to have a 7-cm sized tumor of the small intestine and swollen lymph nodes. He underwent resection of the bowel and lymph nodes. Histological examination of the resected specimens revealed compact tumor cells from mucosa to subserosa and infiltrate into the fat tissue of the mesentery and the lymph nodes. Pathological examination of the resected specimen revealed plasma cell-like round cells, Dutcher bodies, and Russell bodies. Immunohistochemical examination showed that the cytoplasm of the tumor cells were positive for CD138 and the nuclei were positive for cyclin D1. Four months after surgical resection, the patient had recurrence of tumor cells in the para-aortic lymph nodes and lumbar vertebrae. Chemotherapy treatment was ineffective. Surgical resection followed by chemotherapy is thought to be effective in the case of intestinal obstruction, although there is a possibility of devastation which is resistant to chemotherapy. We propose that tumor cells positive for cyclin D1 may play a key role in devastation and could be a useful indicator of prognosis.