A soft-tissue calcification: differential diagnosis and pathogenesis

An autopsy of a 72-year-old white male revealed a 30.5 x 5.1 cm vertically aligned heterotopic ossification just deep to a 30.5 cm midline abdominal scar. The ossified mass was determined to be a heterotopic ossification or myostitis ossificans (MO) traumatica resulting from an abdominal surgical incision during life. While, MO traumatica is relatively common accounting for roughly 60-75% of patients with soft-tissue ossification, heterotopic ossification of abdominal incisions are relatively rare and thus infrequently reported. This article details the manifestation of this relatively large heterotopic bone and provides a comprehensive review of the literature and pathogenesis of this unusual ossification. A review of the English literature from 1920 to the present produced only a handful of articles for a total of 185 reported cases. All had bone formed within vertical incisions, usually within 1 year of surgery, and 89% were males. Knowledge of this phenomenon and the variable size at presentation is useful to both the autopsy pathologist and the anthropologist in generating a diagnosis for abnormal calcifications.