Monomorphic Epitheliotropic Intestinal T-Cell Lymphoma Concomitant with Nontuberculous Mycobacteria Infection: A Case Report.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare non-Hodgkin lymphoma originating from mature T lymphocytes within the intestinal epithelium. It is a distinctly heterogeneous malignant tumor with a highly aggressive nature and poor prognosis. Nontuberculous mycobacteria (NTM) are ubiquitous and can infect immunocompromised hosts. NTM infections pose an increased risk of morbidity and mortality in patients with hematological malignancies, with a reported prevalence of 1.4% in those with lymphoma. Here we present a case of a 47-year-old patient, who experienced diarrhea for 8 months. Initially, the condition was misdiagnosed as intestinal tuberculosis. However, it was later correctly diagnosed as MEITL combined with NTM infection through intestinal histopathological biopsy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of the sputum. To our knowledge, it is the first documented instance of MEITL combined with NTM infection. This case serves as a reminder that NTM infection is one of the potential infectious complications in patients with MEITL.