Anaplastic large T-cell lymphoma (ALCL) is a rare form of Non-Hodgkin's lymphoma with an annual incidence of 0.25 cases per 100,000 people. Patient typically present with rapidly progressive adenopathy with usual extra nodal site involving the skin, liver, lungs and bone. Colon involvement is extremely rare and there have been only a few cases described in literature. We present a rare case of ALCL, ALK (anaplastic lymphoma kinase) negative tumor with initial presentation as a sigmoid colon mass.
62 year old male referred to the Gastroenterology clinic with abdominal pain, diarrhea associated with 30 lbs. weight loss over 3 months. Patient admits to a 50 pack year smoking history and no prior colon cancer screening. Initial work up including basic blood work and stools studies did not reveal any significant abnormality. CT abdomen revealed thickening of the sigmoid colon. Colonoscopy revealed a large polypoid, partially obstructing mass at 32 cm from the anal verge in the sigmoid colon (Image1). Biopsies obtained revealed colorectal mucosa with dense atypical lymphoid aggregate, positive for CD3, CD5, and BCL-2; negative for CD20, BCL-1, and BCL-1. Ki-67 highlighted more than 90% of the atypical lymphoid cells. Immunostains were positive for CD30, CD2, CD3, CD4, and BF-1; negative for ALK, CD20, CD7, CD8, CD56 and CD57 (Image 2,3). Molecular testing for ALK gene rearrangements by FISH were negative, favoring a diagnosis of anaplastic large cell lymphoma, ALK-negative. Patient was evaluated by oncology and was promptly started on chemotherapy. Unfortunately due to the aggressive nature of the lymphoma and poor response to chemotherapy, patient developed CNS involvement and later died from cardiorespiratory arrest. Anaplastic Large cell lymphoma (ALCL) is a rare peripheral T-cell lymphoma with classic findings of large lymphocytes with horseshoe-shaped nuclei with homogenous expression of CD 30+ on the membrane. There are 2 distinct subtypes identified based on the presence or absence of genetic abnormality associated with translocation involving ALK. ALCL, ALK negative typically have a clinically aggressive course and poor prognosis. Systemic ALK-negative ALCL patients have a worse prognosis than ALK-positive ALCL patients, with five-year survival rates of 49% and 70%, respectively. Gastrointestinal involvement with ALCL, ALK negative is extremely rare and to our knowledge only a few cases have been reported in literature.