To the Editor.—
In the innocuous cutaneous nodule, commonly called dermatofibroma, may be hidden secrets about the influence of mesenchyme upon epithelium. Epidermal hyperplasia of various kinds, including basal cell carcinoma-like proliferation, is a well recognized concomitant of this primary dermal process. Recently, the occurrence of focal keratosis follicularis overlying dermatofibroma was reported.1 We call attention to a second similar case, a solitary lesion on the leg of a 44-year-old white woman who had no other evidence of Darier's disease. This phenomenon, keratosis follicularis overlying dermatofibroma (Fig 1 and 2), may be one clue to the riddle of mesenchymal-epithelial interaction and to the dynamics of Darier's disease.
Ackerman AB, Hyman AB. FOCAL KERATOSIS FOLLICULARIS OVERLYING DERMATOFIBROMA. Arch Dermatol. 1971;104(2):219. doi:10.1001/archderm.1971.04000200107022