T-cell lymphomas diffusely involving the intestine: report of two rare cases.

Two adult cases of extranodal malignant lymphoma diffusely involving the intestinal wall are reported. Lymphoblastic lymphoma in case 1 (68-year-old male) and small lymphocytic lymphoma in case 2 (48-year-old male) were initially manifested as protein-losing enteropathy or malabsorption syndrome. In case 1, the patient died of massive ascites and intestinal bleeding 10 months after presentation. Autopsy revealed diffuse and extensive lymphomatous involvement of the small and large intestine, peritoneum and liver. The patient in case 2, showing low-grade diffuse lymphomatous invasion throughout the small bowel mucosa without involving other organs, is currently being followed up. Surface marker studies revealed previously undescribed phenotypes, such as CD4/CD8 double-positive blastoid T cells in case 1, and CD8-positive suppressor/killer T cells in case 2. T-cell receptor alpha/beta was expressed on the lymphoma cells in both cases. Epstein-Barr virus infection was not evident. The gut-associated nature of the T-lymphoma cells, possibly of extrathymic origin, is discussed.