CLINICAL HISTORYThis is a case of a 64-year-old man, kidney transplant (KTx) recipient, who presented 3 years ago, complaining for fatigue, headaches, dizziness, and a 7% weight loss during the past few months. His medical history was significant for end-stage renal disease, 18 months of dialysis, and KTx from a deceased donor 23 years ago. Both patient and donor were positive for cytomegalovirus (CMV). He was maintained on mycophenolate mofetil and cyclosporine (C2, 502 IU/mL) and renal function was stable (estimated glomerular filtration rate, 55 mL/min per 1.73 m 2 ). Physical examination and imaging studies (ear nose throat, nerves, cervical vessels) were unrevealing. The laboratory work-up was significant for anemia and iron deficiency. Endoscopy discovered a large exophytic mass of the anion colon (Figure 1), proximal to the ileum, causing stenosis. Histopathology showed an infectious granulomatous pseudotumor, with dense infiltrations of plasma cells and well-recognized nuclear inclusions of CMV ( Figure 2) among endothelial cells and macrophages. Serum polymerase chain reaction for CMV was constantly negative while C-reactive protein and cancer markers were normal. As the diagnosis of CMV pseudotumor, in the absence of viremia was established, intravenous ganciclovir was administered (2.5 mg/kg per day) for 3 weeks, followed by oral val-ganciclovir for a total of 3 months. Close monitoring and sequential endoscopies were performed subsequently. Colonoscopy 3 months after diagnosis showed that the pseudotumor remained stable in size, whereas the immune-fluorescent stain for CMV became negative. Six months after diagnosis, a clear decrease of the mass size, was evident, with negative specimens for CMV by pathology. To date, after 3 years, the patient is in good health. FIGURE 1. A large exophytic mass, revealed by endoscopy, in the colon of a KTx recipient.FIGURE 2. Immunohistopathology revealed nuclear inclusion with positive nuclear immune expression of CMV antigen (in the center of the image).
