Multifocal variant of heterotopic ossification

In this case report, we present a 25 year follow-up of a single patient with a previously undescribed multifocal variant of heterotopic ossification. The patient presented with multiple occurrences of lesions similar to myositis ossificans atraumatica as well as some lesions resembling exostoses/osteochondromas. Several images and histological sections show the range of appearances and locations of her somewhat disparate lesions, including an exostosis with intraspinal extension. Until additional similar cases are brought forward, we consider this a unique variant of heterotopic ossification. The precise aetiology of this patient's condition is unknown.