Peripheral T-cell lymphoma with gastrointestinal involvement and indolent T-lymphoproliferative disorders of the gastrointestinal tract.

The 2017 WHO classification includes a new provisional entity of indolent T-lymphoproliferative disorders of the gastrointestinal tract (ITLPD-GIT). We investigated GI involvement of peripheral T-cell lymphoma (PTCL). Eighty-two patients were diagnosed with PTCL during 2007-2017. Eleven patients (13 %) had histologically-confirmed GI tract involvement {3 monomorphic epitheliotropic intestinal lymphoma (MEITL), 3 extranodal NK-/T-cell lymphoma nasal type (ENKL), 2 PTCL, not otherwise specified, 1 adult T-cell leukemia-lymphoma, 2 ITLPD-GIT}. Three patients each had lesions in the small intestine and multiple lesions, two each in the stomach and colon, and one in the duodenum. Six of the 11 patients remained alive. No perforation/stenosis was observed after chemo-radiotherapy, although one patient with ENKL developed gastric bleeding during chemotherapy. One patient with ITLPD-GIT (CD4-/CD8+/Ki67Low) with a colonic lesion showing diffuse edema and multiple aphtha by endoscope and diarrhea, initially diagnosed with MEITL, had active but stable disease after various chemotherapies for 1 year and no therapy for the next 5 years. Another patient with ITLPD-GIT (CD4+/CD8+/Ki67Low) with a localized gastric lesion and slight epigastralgia was in remission for 1 year after radiation. In conclusion, about 10 % of PTCLs were complicated by GI tract lesions and most had a poor prognosis. ITLPD-GIT should be considered as a differential diagnosis based on histology and clinical course. Local complications after chemo/radiotherapy in PTCL with GI involvement were not frequent.