[Solitary liver tumor as a manifestation of polyarteritis nodosa]

A 65-year-old female was admitted with fever of unknown origin.

Abdominal computed tomography showed a solid mass (7.5 cm in diameter) with central fluid, located in the right lobe of the liver. Fine-needle aspiration cytology was unremarkable. Further work-up procedures for suspected liver abscess included colonoscopy, which surprisingly revealed adenocarcinoma at 13 cm from the anal orifice.

Both lesions in the rectum and liver were resected. While a moderately differentiated (G2) adenocarcinoma of the rectosigmoid junction (stage T3/ N0) was confirmed, histology of the hepatic mass showed liver infarction due to polyarteritis nodosa of the medium-sized arteries. Treatment with 20 mg/d prednisolone was initiated and tapered off over the next three months. The clinical course after discontinuation of corticosteroids was unremarkable over a 6-month follow-up.

It is suggested that polyarteritis nodosa of the liver occurred in this patient as a paraneoplastic phenomenon and subsided after resection of colorectal cancer and short-term immunosuppression with prednisolone.