Scrape cytology of myositis ossificans: report of a case and analysis of the cytologic findings described previously.

Myositis ossificans is a reactive, ossifying process within soft tissues, which by its clinical and histological features is considered a pseudosarcomatous lesion. There are few reports that describe the cytologic findings in myositis ossificans, and each of these mentions different cellular composition. We describe the cytology of a case of myositis ossificans in a 14-year-old boy with clinical diagnosis of soft tissue sarcoma, and analyze the most common cytologic findings reported previously of this entity. We conclude that the different cellular composition reported, reflects the different histologic components of this lesion according to the area (zonation phenomenon), and that clinico-radiologic correlation is essential for the cytological diagnosis.