PET/CT of fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP) is an exceedingly rare genetic disorder of connective tissue characterized by extensive and irreversible heterotopic ossification of soft-tissue masses that develop in response to inflammation or trauma. Successful management relies on preventative measures and avoidance of invasive procedures such as intramuscular injections and biopsies. Early diagnosis can prevent extensive heterotopic ossification and is possible with recognition of the classic clinical findings in the feet in association with rapidly evolving soft-tissue masses of the trunk and extremities. Unfortunately, in 87% of the 269 previously reported cases, the diagnosis was not considered initially. Patients are often subjected to biopsy of the soft-tissue masses. The pathology of the fibrodysplasia ossificans progressiva is often confused with sarcoma. These patients might be imaged with PET as part of a standard oncological work-up. We present the first reported PET/CT images of a patient with FOP in order to alert radiologists to this diagnostic pathway. Awareness of the disorder might prevent further unnecessary interventions that can lead to extensive deformity and suffering.