Diagnostic Challenges in Diffuse Large B-Cell Lymphoma in a Young Liver Transplant Patient with Ulcerative Colitis: A Case Report.

BACKGROUND Diffuse large B-cell lymphoma (DLBCL) is the most common form of malignant lymphoma. The hypothesis that age-related immune decline plays a role in the development of lymphoma is well established and exemplified by the association between Epstein-Barr virus (EBV) and DLBCL. This report describes a 22-year-old liver transplant patient with ulcerative colitis (UC) presenting with ileus and diffuse large B-cell lymphoma (DLBCL). Because of the symptoms, an exacerbation of UC was initially suggested, which contributed to a delay in definitive diagnosis. CASE REPORT A 22-year-old patient with a medical history of ulcerative colitis, liver transplantation, and use of immunosuppressive drugs presented gradually progressive abdominal pain, bloating, and, eventually, lack of bowel movements. Initially, abdominal X-ray revealed the presence of radiological features consistent with sub-ileus/ileus. Then, the serological tests for EBV in the IgG class yielded positive results. Subsequently, the contrast-enhanced abdominal and pelvic computed tomography (CT) scans revealed the presence of enlarged lymph nodes forming a conglomerate. A percutaneous thick-needle biopsy of a conglomerate of lymph nodes in the abdominal cavity was performed, which revealed DLBCL. After diagnosis, the patient underwent 6 cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy, achieving remission. CONCLUSIONS This case report emphasizes that clinicians need to consider the risk of oncogenesis associated with the prolonged use of immunosuppressive agents and EBV-seropositive infection status. Screening for EBV before initiating immunosuppressive therapy should be compulsory. EBV-negative patients on immunosuppression must especially avoid EBV infection, while EBV-positive patients must be monitored more closely due to higher oncological risk.