Hypocellular Plaque-Like CD34-Positive Dermal Fibroma (Medallion-Like Dermal Dendrocyte Hamartoma) Presenting as a Skin-Colored Dermal Nodule.

Plaque-like CD34-positive dermal fibromas, also known as medallion-like dermal dendrocyte hamartomas (MDDHs), are a recently recognized group of congenital and acquired spindle cell neoplasms that may appear histologically similar to dermatofibrosarcoma protuberans. Recognizing the clinical heterogeneity of this neoplasm and the subtle pathologic differences are crucial to making the correct diagnosis and avoiding the aggressive surgical intervention required to treat a dermatofibrosarcoma protuberans. We present the case of a 9-year-old girl with an acquired variant of a plaque-like CD34-positive dermal fibroma without clinical epidermal change. Our case expands the clinical spectrum to include an acquired variant of a plaque-like CD34-positive dermal fibroma without clinical epidermal change. Examination of more cases is needed to determine whether all clinical variants are truly subtypes of the same neoplasm or represent distinct CD34-positive spindle cell proliferations.