Osamu Takeuchi

Primary isolated extramedullary plasmacytoma of the colon.

Dear Editor, Plasmacytoma is an immunoproliferative monoclonal disease of the B-cell line that originates from malignant transformed plasma cells. Plasmacytoma, or plasmoma, was originally mentioned by Unna in 1891 and first described by Schridde in 1905. It is a tumor composed almost exclusively of plasma cells that are arranged in clusters or sheets with a scant, delicate, supportive, connective tissue stroma. Four different types of plasma cell tumors were described by Dolin as follows: (1) myelomatosis or multiple myeloma (MM); (2) solitary myeloma of bone; (3) plasma cell leukemia; and (4) extramedullary plasmacytoma (EMP). EMPs account for only 3–5% of all plasma cell diseases. Although they occur in the upper air passage, nasal cavity, and paranasal sinuses in 75% of cases, a small percentage is found in the gastrointestinal tract, especially in the stomach and small intestine. A solitary tumor or primary localization in the colon is extremely rare. Here, we report a rare case of a primary isolated extramedullary plasmacytoma of the ascending colon and its clinical course after surgery and also present a review of the literature. A 64-year-old man was brought to our hospital by ambulance with a 1-month history of the aggravated pain in the right lower abdomen. Physical examination revealed a palpable mass of 10 cm in diameter at the right upper quadrant and tenderness in the same location, but there was no sign of peritonitis. None of the lymph nodes were palpable from the body surface. An abdominal X-ray showed ileus and he was taken to the hospital for examination and treatment. Laboratory data on admission revealed that white blood cell count was 9600/μl, hemoglobin was 12.6 g/ml, lactate dehydrogenase was 425 IU/L, and C-reactive protein was 9.12 mg/dl. Serum carcinoembryonic antigen and CA19-9 were within their normal limits. Total protein was 7.1 g/dl and albumin was 2.7 g/dl, but serum protein electrophoresis was not performed. A barium enema and colonoscopy demonstrated a severe stricture due to an irregular circular tumor with ulceration of the ascending colon where the fiberscope was unable to pass through. The histological diagnosis of a biopsy specimen was group III, ulcer with degenerative atypical cells. An abdominal computed tomography (CT) scan revealed a tumor of 9 cm in diameter in the ascending colon which seemed infiltrating into the posterior portion of the right lobe of the liver. In addition, the spread of inflammation was seen in the right retroperitoneal space next to the tumor. Under a diagnosis of ascending colon carcinoma or lymphoma, a semi-emergency operation was performed because the colon was nearly obstructed. At laparotomy, there was a small amount of slightly bloody ascites, and the cytological diagnosis of these ascites was class II. No dissemination was observed. A large mass involving the ascending colon and infiltrating into the liver was found, and right hemicolectomy, lymph node dissection, excision of Gerota’s fascia, and partial resection of the posterior portion of the liver were performed. MacroscopiInt J Colorectal Dis (2008) 23:719–720 DOI 10.1007/s00384-008-0439-7