A rare primary malignant solitary fibrous tumour of the liver

Abstract

Solitary fibrous tumour (SFT) usually occurs in the pleura but can rarely present as a primary liver tumour. Although SFT is usually slow growing and has a favourable prognosis, few malignant SFTs have been reported in the literature. We present a malignant SFT in a 78-year-old male who presented with acute epigastric pain. CT of the abdomen showed a large mass in left lobe of liver. A fine needle aspiration after embolisation and CT guided core biopsy were reported as solitary fibrous tumour. He underwent a left hemi hepatectomy showing a 17×13cm encapsulated tumour attached to the liver capsule. Microscopically the tumour was composed of spindle cells amongst wavy collagen fibres. The stroma showed both myxoid and hyalinised areas as well as areas of necrosis with stag horn like dilated vessels (hae-mangiopericytoma like appearance). Focally there was marked cellular pleomorphism with more than 4 mitosis per 10 high power fields. Tumour cells showed positivity for CD99, CD34, BCL-2 and vimentin. These features are suggestive of a high grade malignant SFT of the liver. The patient remains free of recurrence on follow-up. Most of the extra pleural SFTs behave in a benign fashion, but 10–15% tend to be aggressive. There is no strict correlation between morphology and behaviour in these tumours. This case is presented for its rarity.