Keloid : Differential Diagnosis
Differential Diagnosis (continued from the previous image): Acne Keloidalis: It is the commonest form of scarring alopecia, usually seen in the nape of the neck in African-American males (shown here). The term is a misnomer since it is not associated with acne nor is there keloidal collagen microscopically, although it clinically resembles keloid. Histologically, there is follicular destruction, lymphoplasmacytic infiltrate, and fibrosis.Sclerotic Fibroma: It is a solitary dermal nodule composed of thick, glassy bundles of collagen with a storiform pattern. Microscopically, it is similar to fibrous nodules seen in multiple hamartoma syndrome (Cowden syndrome). Keloidal Dermatofibroma: Clinically, this variant appears like usual dermatofibroma (benign fibrous histiocytoma) with no resemblance to keloids; however, the histologic features include the presence of thick, keloid-like collagen bundles.