Heterotopic ossification in upper midline abdominal scars.

Heterotopic ossificaton of the upper midline abdominal incision scar is reported in seven patients. This disorder may follow abdominal operations via vertical incisions. The cause is unknown. All patients were men in their fifties. The calcification resembled a "rib" and occurred in upper midline incisions between the peritoneum and fascia, fixed more to the fascia. Excision of the mass was performed in six cases. Excision is recommended only in symptomatic cases, and should be wide enough to avoid recurrence. In the differential diagnosis several other wound complications as well as intra-abdominal malignancy should be considered.