Osteoma Cutis

Osteoma cutis, more simply called cutaneous ossification, is an uncommon condition. It can be classified as primary and secondary forms.

Primary Osteoma Cutis

Primary osteoma cutis is further divided into two subclasses based on whether or not it is associated with Albright hereditary osteodystrophy.

Albright hereditary osteodystrophy has a poor long-term prognosis. Cases of primary osteoma cutis associated with Albright hereditary osteodystrophy can either have pseudohypoparathyroidism or pseudopseudohypoparathyroidism. Patients are generally obese and have short stature, developmental disabilities, round facies, and basal ganglia calcifications.

Cases of primary osteoma cutis not associated with Albright hereditary osteodystrophy can be further divided as multiple miliary osteoma of the face (usually women), isolated osteoma (single site), widespread osteoma (occurs in the neonatal period), and congenital plaque-like osteoma.

Secondary Osteoma Cutis

Secondary osteoma cutis is relatively more common than primary osteoma cutis and occurs in association with prior skin inflammation (e.g., syphilis, pyogenic granuloma, folliculitis), injury, or tumor. Tumors associated with secondary osteoma cutis include metastatic bronchogenic carcinoma, basal cell carcinoma, hemangioma, and pilomatricoma, among others.

References

Fazeli P, Harvell J, Jacobs MB. Osteoma cutis (cutaneous ossification). West J Med. 1999 Oct;171(4):243-5.