Lesional biopsies revealed that the patient had osteoma cutis, a skin condition in which bone ossification occurs within the dermis. It has an incidence of 1.2 to 1.7 cases per 1000 skin lesion biopsies. Sixty-eight percent of osteoma cutis cases are benign.
The primary form of osteoma cutis is associated with certain genetic disorders, such as Gardner’s syndrome and Albright’s hereditary osteodystrophy. It arises without a preexisting lesion.
The secondary form of osteoma cutis, which this patient had, often arises within a cancerous lesion or chronic inflammation. Given this patient’s history of trauma followed by recurrent ulceration (which may not have completely resolved), her physicians suspected that chronic inflammation was the cause of the osteoma cutis.
The differential diagnosis includes calcinosis cutis, or deposition of insoluble calcium compounds in the skin without true bone formation. Other diagnoses to consider for non-healing or treatment-resistant ulcers include infection, vasculopathy, pyoderma gangrenosum, and malnutrition. Since the diagnosis of osteoma cutis is made primarily by pathology, suspicious lesions should be biopsied.
In this case, the patient was prescribed minocycline 100 mg BID for 14 days for the superficial wound infection, with plans to extend treatment as needed based on wound healing. She also received care at a local wound clinic for incomplete resolution of the ulceration and biopsy sites.
Adapted from: Sanchez AT, Weaver SP, Glass DA. Photo Rounds: painful toe ulcers. J Fam Pract. 2013;62:37-38.