Myositis ossificans with hoffa’s disease (Lipoma Arborescens): Usual mimicker of soft tissue sarcoma

Abstract

Myositis Ossificans is a benign heterotopic ossification mainly occurs in muscles and soft tissue. Hoffa’s disease (Lipoma Arborescens) is a rare benign lesion characterized by villous lipomatous proliferation of synovial membrane. Due to its unusual property of abnormal ossification in muscles and soft tissue, myositis ossificans presents a diagnostic and therapeutic problem to pathologist and clinician respectively, as it mimics soft tissue sarcoma. We present a case of 14 year male presented with left thigh swelling near knee joint with restricted movements. Clinically it was suspected as synovial sarcoma. Wide local excision of mass and synovial membrane excision was done. Final diagnosis on histopathology was given as Myositis Ossificans with Hoffa’s disease. The aim of this case is to highlight the unusual combination as myositis ossificans with lipoma arborescens together due to its rarity and sarcoma mimics. Such type of combination was reported for the first time in present literature in Indian context. Keywords: Myositis ossificans, Hoffa’s disease, Lipoma arborescens, Synovial sarcoma, Tumor, Mimics.