Histologic evaluation showed lamellar bone with a fatty marrow that extended from the midreticular dermis into the subcutaneous fat. Haversian canals and numerous osteoblasts were present. Polarization showed birefringence consistent with lamellar ossification. A general physical examination of the patient revealed no abnormalities. The results of laboratory investigations, including circulating levels of calcium, phosphorus, and parathyroid hormone; a complete blood cell count; urinalysis; and serum chemistry studies, were normal.
Dermal Plaques of the Face and Scalp. Arch Dermatol. 2007;143(1):109-114. doi:10.1001/archderm.143.1.109-h