Table 1. Classification of Osteoma Cutis

Primary Osteoma Cutis	Secondary Osteoma Cutis
Albright’s hereditary osteodystrophy	Inflammatory processes*
Fibrodysplasia ossificans progressive	Traumatic processes†
Progressive osseous heteroplasia	Neoplastic processes‡
Congenital plate-like osteoma cutis
Idiopathic solitary or multiple osteomas, including military osteomas

*Inflammatory processes – infections, acne, chronic venous insufficiency, scleroderma, dermatomyositis

†Traumatic processes – scars, injection sites, hematomas

‡Neoplastic processes – nevi, basal cell carcinomas, pilomatricomas, trichoepitheliomas, hemangiomas,
pyogenic granulomas, schwannomas, lipomas, chondroid syringomas, organoid nevi, epidermal cysts,
dermoid cysts, dermatofibromas, desmoplastic melanomas, cutaneous metastases, sebaceous hyperplasia,
fibro-osseous pseudotumor of the digits