MRI of soft tissue masses of the hand and wrist.

The vast majority of soft tissue mass lesions of the wrist and hand are benign [1, 2]. In practice, the most common lesions encountered are ganglia. The most frequently seen solid masses include giant cell tumours of tendon sheath (GCTTS), lipomas, Dupuytrens contractures, nerve sheath tumours, glomus tumours, haemangioma/vascular malformations and synovial pathology. In general MRI is unable to differentiate between benignity and malignancy, but in many circumstances a specific diagnosis may be achieved by taking into account the location of the lesion within the hand or wrist and its signal characteristics [2–4]. Plain films and CT may detect calcification and allow assessment of adjacent bony structures but unlike MRI do not offer much in the way of tissue characterization. Ultrasound has an extremely useful role in localizing lesions and determining if the lesion is cystic or solid [5, 6], but further tissue characterization is limited. This pictorial review covers the MRI appearances of the most commonly encountered soft tissue masses of the wrist and hand, and describes the main features, specifically the signal characteristics and location, that help differentiate them.