Isolated hepatic tuberculoma after orthotopic liver transplantation: a case report.

Tuberculosis (TB) is an unusual infection in liver transplant recipients, its incidence ranges from 0.9-2.3% in developed countries1. In these patients, TB is frequently seen as disseminated disease or as pulmonary disease, and liver involvement has been described only in cases of disseminated disease. Here we describe the uncommon case of a liver transplanted patient who developed an isolated liver abscess due to Mycobacterium tuberculosis (BK). A 58-year-old man was referred to our unit 8 months after orthotopic liver transplantation (OLT) for cryptogenic cirrhosis. He complained of episodes of high fever and night sweats for over 1 month. On admission he had intermittent fevers up to 39°C, and no clear focus of infection determined by a physical examination. He did not complain of any other symptoms. The patient was on chronic immunosuppressive treatment with tacrolimus (1.5 mg bid) and steroids (prednisone 10 mg/day) due to the presence of lupus anticoagulant phenomenon. Results of blood analyses were as follows: white blood cell count 6.95 103 cells/l with 84% neutrophils, 9.1% lymphocytes, 4.6% monocytes; platelets 151 109 cells/l; haemoglobin 13.7 g/dl; erythrocyte sedimentation rate 36 mm/h (normal value < 15 mm/h); C-reactive protein 132 mg/l (normal value < 80 mg/l); fibrinogen 6190 mg/l (normal value 2000-4000 mg/l); gamma-glutamyl transferase was 2.1 times the upper normal values, alkaline phosphatase was 1.2 times the upper normal value. Serum transaminase, bilirubine, creatinine, lactate dehydrogenase and serum electrolytes were normal. Serology for parvovirus, cytomegalovirus and Epstein-Barr virus was negative. Blood cultures excluded bacterial infection. Radiological examination of the chest was normal. An abdominal ultrasonograpy revealed a 35 mm solid hypoechoic mass with poorly defined walls in the fourth segment (Fig. 1) without dilatation of the biliary tree. The mass was not seen on a previous ultrasound examination done by the same operator 3 months before. A Doppler study did not show arterial or venous blood flow inside the mass, whereas the hepatic artery flow was normal. A contrast-enhanced computed tomography of the thorax and abdomen was then performed, showing a normal pattern of lungs, and confirming a 50 mm lesion in the fourth hepatic segment, with the pattern of a partly solid and only in small part liquefied abscess. No enlarged lymph nodes were detected. During this procedure, by inserting a 20G needle in the liquid part of the mass, an aspiration biopsy was obtained. The small quantity of collected material presented as a dense, purulent, slightly haematic fluid. The microbiological examination of the specimen showed a large amount of acid-fast bacilli. The patient was treated on an empirical basis with clarithromycin (500 mg bid), ethambutol (400 mg tid) and levofloxacin (500 mg bid), and rapidly improved, with fever resolution on the second day of treatment. The erythrocyte sedimentation rate and C-reactive protein normalised 8 days later. Blood levels of tacrolimus progressively increased, and its dosage was reduced to 0.5 mg every 3 days. The patient was discharged from the hospital on clarithromycin, ethambutol and levofloxacin. After 1 month, the bacterial strain was identified as Mycobacterium tuberculosis (sensitive to all tested drugs).