Cutaneous soft tissue tumours: an update on tumours with perivascular and myoid differentiation

Cutaneous tumours showing pericytic features show a wide morphological spectrum with differentiation towards glomus cells, haemangiopericytomatous areas and outright myoid differentiation. This tumour group includes glomus tumour and its variants, myofibroma, myofibromatosis, myopericytoma and angioleiomyoma. The majority of these tumours are benign but criteria for malignancy are only poorly established. In the skin, malignant examples are particularly rare. Familiarity with these tumours and their wide histological range is important to avoid misdiagnosis as other mesenchymal neoplasms with more aggressive behaviour. This article emphasizes the clinical and histological features of the cutaneous tumours with pericytic differentiation. It also includes a discussion of cutaneous myoid tumours for which they may readily be mistaken.