Aggressive myxoinflammatory fibroblastic sarcoma with multiple site metastases.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare soft tissue sarcoma which was initially observed in acral sites and characterised by spindle cells, pleomorphic bizarre cells and distinctive large Reed-Sternberg-like cells admixed with an intense inflammatory cell infiltrates. MIFS manifests as a slow growing often superficial lesion which can be mistaken as infectious or chronic inflammatory process or benign tumours such as nodular fasciitis, giant cell tumour of tendon sheath or synovial pseudocyst. We report a rare presentation of a MIFS in a 38-year-old man with extensive local spread from subcutaneous tissue to the ankle joint and bones as well as multiple synchronous metastases to lung, sixth rib and vertebra. Our case is peculiar for its aggressive clinical behaviour with short duration, fast growth and extensive metastases, a feature infrequent in MIFS. © BMJ Publishing Group Limited 2018. No commercial re-use. See rights and permissions. Published by BMJ.