Myopericytoma around the knee: mimicking a neurogenic tumour.

Myopericytoma is a rare, usually benign soft tissue tumour that arises most commonly in the dermis and subcutaneous soft tissue of the lower extremities. In this article, we present an unusual case of myopericytoma occurring in the deep soft tissue around the knee that mimicked a neurogenic tumour. Myopericytoma can be confused with neurogenic tumour when located in deep soft tissue and adjacent to nerve bundles. Preoperative MRI and colour Doppler ultrasound may help differentiate myopericytoma from neurogenic tumour by revealing the hypervascular nature of the tumour.