Isolated gastrointestinal posttransplant lymphoproliferative disorder in a child

Abstract

We report a 12-year-old male renal allograft recipient, 10 months following the transplant surgery, who presented with diffuse abdominal pain, constipation, vomiting, and weight loss of 5 kg in 2 months. He was on standard maintenance immunosuppression (tacrolimus/mycophenolate mofetil/prednisolone) and had not received induction agents. Upper gastrointestinal (GI) endoscopy showed nodularity in the body of the stomach, and colonoscopy showed deep ulcers in the sigmoid colon and descending colon. Biopsy from the lesions showed dense infiltration of atypical lymphoid cells (B-cell markers, CD20, CD30, and BCL2 being positive), with immunohistochemistry showing strong positivity for Epstein–Barr virus (EBV). EBV DNA polymerase chain reaction in the blood was strongly positive (2200 copies/mL), confirming EBV-positive posttransplant lymphoproliferative disorder (PTLD). Positron emission tomography–computed tomography and bone marrow biopsy confirmed that the disease was confined to the GI tract. It is a rare complication seen after solid organ transplantation occurring usually in the 1st year after transplant. The most important risk factor is a higher degree of immunosuppression; tacrolimus levels remained high in spite of repeated revisions of the drug dose in our case. The patient was treated with injection rituximab (dose: 375 mg/m2), weekly injections of four doses, and his immunosuppressive medications were reduced by 50%. He had a good symptomatic relief. PTLD confined to GI tract is rare; constipation as a presenting manifestation is very rare. A high index of suspicion is essential to make an early diagnosis.