Benign Miliary Osteoma Cutis of the Face: A Common Incidental CT Finding

D. Kim, G.A. Franco, H. Shigehara, J. Asaumi, P. Hildenbrand

Osteoma cutis of the face represents a primary or secondary formation of ossific foci in the facial skin. Its primary form has been sparsely described in the plastic surgery and dermatology literature. As radiologists, we routinely encounter incidental, very small facial calcified nodules on CT studies performed for a variety of unrelated reasons. We hypothesized that this routinely encountered facial calcification represents primary miliary osteoma cutis and is a common, benign, age-related finding. We retrospectively reviewed 1315 consecutive sinus CTs obtained during an 8-month period and their associated demographics. The number of dermal radiopaque lesions with Hounsfield units of >150 was counted, and we analyzed the association between the prevalence of these lesions and patients' demographics with logistic regression methods. Five hundred ninety-nine males and 716 females from 4 to 90 years of age were included in the study (mean, 52 versus 51 years; P = .259). Among these, 252 males and 301 females had small facial calcified nodules (42.1% versus 42.0%, P = .971). The patient's age was a statistically significant predictor for having facial calcified nodules (odds ratio = 1.02, P < .001), while the patient's sex was not (P = .826). Facial calcified nodules, observed in routine head and face CT imaging, are common, benign, age-related findings, which have been largely overlooked in the radiology literature. It is a manifestation of primary miliary osteoma cutis.