Indolent peripheral T-cell lymphoma involving the gastrointestinal tract.

We describe an unusual case of indolent peripheral T-cell lymphoma with multifocal involvement of the gastrointestinal tract. The patient, a 42-year-old Asian man, has been followed up for more than 10 years without chemotherapy and multiple gastrointestinal biopsies showing similar findings. Histologically, the neoplasm expanded into the lamina propria and/or focally extended into the submucosa and was composed of small- to medium-sized lymphocytes with slightly irregular nuclear contours and clear cytoplasm and rare large lymphocytes. The tumor cells were positive for CD3, CD8, granzyme B, and TIA-1 (subset) and negative for CD5, CD56, and Epstein-Barr virus-encoded RNA. Molecular studies for T-cell receptor γ and/or β chain gene rearrangement demonstrated the same clone at different sites and times during the course of the disease. Rare cases of indolent peripheral T-cell lymphoma of the gastrointestinal tract have been previously described and need to be further characterized to avoid the use of aggressive chemotherapy.