Anaplastic Lymphoma Kinase-Negative Anaplastic Large Cell Lymphoma with Colon Involvement

1Department of Gastroenterology and Hepatology; 2Department of Pathology, National Hospital Organization, Osaka National Hospital, Osaka, Japan Correspondence and reprints: Dr Yuko Sakakibara, Department of Gastroenterology and Hepatology, National Hospital Organization, Osaka National Hospital, 2-1-14 Houenzaka, Chuo-ku, Osaka city, Osaka 540-0006, Japan. Telephone 81-6-6942-1331, fax 81-6-6946-3569, e-mail yuko.s@onh.go.jp Received for publication June 3, 2015. Accepted June 5, 2015 CASE PRESENTION A 65-year-old man was referred to the authors’ hospital for examination of a painful hard mass in the left buttock. Magnetic resonance imaging revealed a mass in the left ilium, and 18F-fluoro-2deoxy-glucose positron emission tomography/computed tomography revealed uptake in the left ilium and ascending colon. Colonoscopy revealed a reddish ulcerative lesion with protrusions in the ascending colon (Figure 1A). Endoscopy with dual-focus narrow-band imaging revealed dilated, tortuous microvessels and avascular areas in the protrusions (Figure 1B). Histopathological examination of biopsy specimens revealed infiltration of large lymphoid cells with immunohistological characteristics similar to those of the iliac tumour (Figure 2A). Immunohistochemical staining was positive for CD30 (Figure 2B) and negative for anaplastic lymphoma kinase (ALK). Based on these findings, the patient was diagnosed with ALK-negative anaplastic large cell lymphoma (ALCL) with colon involvement. He received six cycles of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy and achieved complete remission. DISCUSSION ALCL is a CD30-positive T cell neoplasm; systemic-type ALCL represents 2% to 3% of all non-Hodgkin lymphomas and 12% to 14% of T cell non-Hodgkin lymphomas (1,2). The WHO classification system divides ALCLs into ALK-positive and ALK-negative groups. Systemic ALK-negative ALCL patients have a worse prognosis than ALK-positive ALCL patients, with five-year survival rates of 49% and 70%, respectively (1). ALK-negative ALCL involves both lymph nodes and extranodal sites (20% of cases) (2). The most frequent extranodal involvement sites are the skin, lungs, liver and gastrointestinal tract, whereas colon involvement is extremely rare (1,2). To our knowledge, only two previous case reports presented endoscopic findings of ALCL with colon involvement; one case showed multiple elevated lesions with ulceration at the apex, and the other showed ulcerated stricture (3,4). If ulcerative colonic lesions are observed on colonoscopy, colon involvement of ALCL should be considered as a rare differential diagnosis.