Transformation of jejunoileal follicular lymphoma into diffuse large B-cell lymphoma detected using double-balloon enteroscopy.

Jejunoileal follicular lymphomas (FLs) are rare and have been reported to undergo histological transformation (HT). We report a case of jejunoileal FL transformation into diffuse large B-cell lymphoma (DLBCL). An 82-year-old woman presented with a 5.5 cm ulcerated jejunal mass, identified through double-balloon enteroscopy. The histopathology report revealed diffuse atypical lymphoid cells, which confirmed the presence of DLBCL. Neoplastic follicles confirmed the presence of FL. Genetic analysis revealed a match between the FL and DLBCL. Following a segmentectomy and chemotherapy, the patient is in remission. Based on this case, we should consider the possibility of jejunoileal FLs transforming into DLBCL.