An unusual finding: Heterotopic ossification located in the subcutis of the iliac region – A case report in the context of current literature

Abstract

Background: Heterotopic ossification (HO) is an ectopic formation of the lamellar bone in the soft tissue. According to the underlying cause, HO can be subdivided into hereditary and acquired forms. We report on an unusual post-mortal finding of a HO in the subcutis at the border of the lower abdomen to the pelvis in a 94-year-old woman. Methods: X-ray analysis as well as histological examination was performed to analyze the structure. Results: Bone structure was confirmed. There were no signs of an acute or chronic inflammation in the surrounding tissue, neither upon macroscopic nor on microscopic examination. The retrospective research of the medical findings did not reveal any indications of an acute event. However, an almost thirty-year-old x-ray image of the lumbar spine showed a radiopaque structure in the region of this HO. To the daughter's knowledge, the body donor had been in a serious car accident in the 1940s, which could be a possible trigger for the observed HO. Conclusions: Literature research revealed this to be the first report of a subcutaneously located HO of this size and shape. Even though the condition and mechanism leading to the development of HO in our case remains unclear, it is still a remarkable finding and reminds the medical practitioner to be always aware of an unusual finding.

Keywords

• Ectopic bone
• Cadaveric specimen
• Dissection
• Gross anatomy
• Heterotopic ossification