Calcification of a preexisting epidermal inclusion cyst (EIC) or pilar cyst.
Calcification of dermal connective tissue in the absence of a cyst (idiopathic).
Clinical: usually young men with a long history of multiple firm or hard nodules measuring up to 3 cm in diameter; overlying skin is generally intact although it may ulcerate and extrude cheesy material (like an EIC).
Histologic features: dermis contains globules of bluish calcific material with or without granulomatous inflammation.
Treatment: surgery as needed.