Heterotopic bone formation in a laparotomy scar: A case report

We present the case of heterotopic bone formation in an upper abdominal scar after a cholecystectomy. The patient, a 48-year-old man, had undergone a cholecystectomy due to a gallstone a year before he had noticed a hard mass that had developed at the incisional scar site. Most cases of heterotopic bone formation have been reported to occur in median epigastric laparotomy scar. As to causes for this bone, we discuss the mechanisms of heterotopic bone formation with regard to the osteogenetic potential of the xyphoid and the linea alba and the metaplastic potential of the surrounding soft tissue. Also, the development of myositis ossificans can be considered as having the same etiology. There seems to be more such cases than are being reported, and when encountering an unexplained subcutaneous hard mass, the possibility that it may be a heterotropic bone formation should be considered before initiating treatment.