CD5-negative mantle cell lymphoma resembling extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue : a case report.

A 71-year-old male underwent an upper gastrointestinal endoscopy ; as a result of a biopsy, extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) was suspected. Abdominal computed tomography scan disclosed an approximately 4-cm-large mass in the ileocecal region. After ileocecal resection, the patient was diagnosed with MALT lymphoma (CD79a(+), CD20(+), CD3(-), CD5(-), CD10(-), and cyclin D1(-)).