Multiple hepatic masses in a 38-year-old male 10 years after renal transplantation

Abstract

The patient is a 38-year-old male, diagnosed with IgA nephropathy at age 24, who underwent renal allograft transplantation 10 years ago. He presented with complaints of fever and non-productive cough. Clinical examination was notable for a low grade temperature (99.5 F), bibasilar crackles and a distended abdomen with overlying varices. Laboratory studies showed anaemia of chronic disease and normal liver function tests, except for a mildly depressed serum albumin level. Serum creatinine was elevated from his baseline of 2.5mg/dl to 4.2mg/dl. Additional past medical history includes former heavy use of alcohol, with none following his transplant. A right sided pulmonary infiltrate was detected on chest X-ray. Following antibiotic therapy for presumed pneumonia, his clinical symptoms resolved and his creatinine reverted to baseline level. An out-patient computed tomography (CT) scan was performed to evaluate the abdominal findings. Massive liver nodules in the lobes were present, replacing the hepatic parenchyma. The largest measured 13.5 cm in the left lobe, with a separate 12.5 cm mass in the right lobe (Figure 1). Radiologically, the lesions were perplexing, with a broad differential diagnosis including abscesses, haemangiomas, benign cystic lesions, metastases or hepatocellular carcinoma. Percutaneous core needle biopsy yielded a moderately cellular spindle cell neoplasm with minimal cellular pleomorphism and no mitotic activity (Figure 2). The spindle cells contained elongated, blunt-ended nuclei with finely stippled chromatin. Immunohistochemistry by the standard avidin–biotin–peroxidase complex method demonstrated myogenic differentiation of the tumour cells, which were immunoreactive to smooth muscle actin. In situ hybridization for EBV virus was strongly positive in >90% of the spindle cell nuclei (Figure 3). These findings are indicative of an EBV-associated myogenic tumour. A reduction of the immunosuppressive agents was recommended to the patient, who declined for fear of impending rejection. Currently he is being followed, with slow expansion in the size of the liver nodules. Six months following diagnosis of the liver lesions, a palpable 4 cm nodule in the right gluteal region developed. Additional smaller nodules in the same region were noted by imaging studies. Percutaneous needle core biopsy illustrated a histologically identical EBV-associated myogenic tumour.