A Rare Case of Plasmablastic Myeloma After Renal Transplant.

Posttransplant lymphoproliferative disorders are a serious complication after solid-organ transplant, with a reported incidence from 2% to 20%. Plasma cell neoplasms in solid-organ transplants represent a rare but increasingly serious complication after solid-organ transplant. We report a case of plasmablastic myeloma, a very rare variant of multiple myeloma with aggressive course and poor prognosis. Few such cases have been reported in the literature in patients after solid-organ transplant. A 41-year-old male patient received a renal transplant from a living unrelated donor (wife) in 2019. After transplant, he was given triple immunosuppression therapy (mycophenolic acid, tacrolimus, prednisolone). In September 2024, 56 months after transplant, the patient presented to our nephrology department due to confusion, weight loss, loss of appetite, and gastric discomfort. Laboratory results showed hypercalcemia, elevated serum creatinine, and thrombocytopenia with anemia, without apparent blood loss. As a result of persistent hypercalcemia and elevated serum creatinine levels, treatment with hemodialysis was initiated. Polymerase chain reaction results were negative for Epstein-Barr virus. After preliminary preparation, bone marrow biopsy was performed, which revealed infiltration by cells with blastic morphology. Immunohistochemical analysis confirmed the finding with more than 80% of cells positive for CD138; the remaining marker tests were mostly negative. The day after the bone marrow biopsy, the patient had progressive deterioration in his health, with severe malaise and disorientation; he developed acute heart failure and pulmonary edema. An urgent hemodialysis was initiated, but it was unsuccessful. The patient died on day 10 of hospitalization. Posttransplant lymphoproliferative disorders and other malignant neoplasms pose a serious posttransplant complication in patients with challenging diagnoses due to overlapping features with other posttransplant complications; such patients most often experience a rapid and atypical course, due to high doses of immunosuppressants.