Abstract
Background: Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is an extremely rare and highly aggressive subtype of peripheral T-cell lymphoma that primarily arises in the intestine. MEITL exhibits a high resistance to conventional chemotherapy and a strong tendency for relapse, resulting in a dismal prognosis. The median overall survival is only about seven months, with most patients succumbing to gastrointestinal complications such as perforation, obstruction, or bleeding. In recent years, advances in molecular biology have highlighted the increasingly important role of genetic testing in the diagnosis and treatment of MEITL. This approach not only facilitates the identification of molecular characteristics of the tumor but also supports the development of individualized treatment strategies. To further elucidate the clinical and genetic features of this disease, we conducted a retrospective analysis of 11 MEITL patients treated at our center.
Methods: Patients diagnosed with MEITL between July 16, 2023 and December 15, 2024 were enrolled in the analysis. Cut-off date for follow-up was July 24, 2025. Clinical data were collected using the electronic medical record system, including age, sex, disease stage, presenting symptoms, and laboratory findings. Heatmaps were drawn to visualize the results of genetic testing, treatment modalities, and patient outcomes. Survival outcomes between different subtypes were compared using Kaplan-Meier curves.
Results: The mean age of the patients was 56.6 years (SD = 12.6), and 9 patients (81.8%) were male. Eight patients (72.7%) were classified as Ann Arbor stage IV and Lugano stage IV. The most frequently involved site was the ileum (n = 6). Most cases expressed CD3 (100%), TIA1 (100%), CD56 (81.8%), and CD7 (72.7%), but were negative for CD30, CD20, CD103, and EBER (all 0%). The most frequently mutated genes were STAT5B (72.7%), SETD2 (63.6%), and JAK3 (45.5%). The median overall survival was 3.0 months (95 % CI 2.0–4.0); Seven patients (63.6%) underwent surgery, and nine (81.8%) received chemotherapy. The complete response (CR) rate was 18.1%. Although the optimal management of MEITL remains unclear, surgery combined with chemotherapy may help improve patient prognosis. Two patients underwent CHOP combined with histone deacetylase (HDAC) or PI3Kδ inhibitors as their frontline regimen, and both of them were survival until follow-up cutoff date.
Conclusion: Based on present data, the most frequently mutated pathways in MEITL patients was JAK-STAT pathway. Surgery combined with chemotherapy may prolong their overall survival. And CHOP combined with HDAC or PI3Kδ inhibitors may decrease risk of mortality of them. However, the relationship between patient prognosis and gene mutations in MEITL should be further investigated.
