BACKGROUND: Fibrodysplasia ossificans progressiva (FOP), also known as Myositis ossificans progressiva or Munchmeyer's disease, is an extremely rare and disabling genetic condition of congenital skeletal malformations and progressive heterotopic ossification (HO). The disease is characterized by congenital skeletal anomalies and progressive ectopic bone formation in connective tissues suchas ligaments, muscles and tendons. The disease has an incidence of about 1 in 2 million population.CASE DETAILS: We report a case of a 2-year and 8-month old male childwith an initial diagnosis of soft tissue sarcoma based on fine needle aspiration (FNAC) of neck swelling.CONCLUSION: Fibroplasia ossificans progressive (FOP) characteristically manifests with bilateral malformation of the great toe and progressive heterotopic ossification (HO). Clinicians and radiologists should be aware of these to prevent permanent disability.KEYWORDS: Fibroplasia ossificans progressive, myositis ossificans