Rare Case of Inflammatory Myofibroblastic Tumour with Atypical Clinical and Pathological Features

Inflammatory myofibroblastic tumour (IMT), typically found in the abdomen, lungs, and mediastinum, is rare in the thigh. The tumour presented with symptoms of pain, a large soft tissue mass, and sinus discharge, which led to a differential diagnosis, including soft tissue sarcoma or atypical lipoma. Histopathological examination revealed a lesion characterised by extensive fibrinous material with myofibroblastic proliferation and eosinophilic material with a surrounding giant cell reaction. Immunohistochemistry (IHC) confirmed the diagnosis of IMT, with additional findings of an organising hematoma and pseudogout. This case highlights the diagnostic challenges IMTs pose when they occur in atypical locations.