Solitary fibrous tumour of the lower leg: an uncommon site with atypical histopathological features.

A 40-year-old man of low socioeconomic status presented with a slowly growing painless mass for 1 year at the antero-medial aspect of the right leg. On local examination, the overlying skin was normal and the mass was soft to firm in consistency, non-tender and freely mobile with no fixity to underlying structures. MRI revealed a lobulated mass with central areas of necrosis and no involvement of underlying muscles and neurovascular bundles suggesting a benign soft tissue tumour. The tumour was totally excised and submitted for histopathological examination, which, along with immunopositivity for CD34, CD99 and focally for Bcl2, led to a confirmatory diagnosis of solitary fibrous tumour with atypical histopathological features of increased mitosis and necrosis. After 4 months of follow-up, the patient was disease free without any recurrence or metastasis.