The so-called Borst-Jadassohn intraepidermal epithelioma is a rare superficial cutaneous lesion, consisting of scaling or verrucous plaques which remain fixed in size or grow very slowly over a period of years. Histologically, it shows cellular changes limited to the epidermis, consisting of nests of darkly staining cells resembling basal cells as well as nearby derangement of squamous cells. It has, therefore, been thought to be an intraepidermal basosquamous-cell carcinoma.
This entity was first emphasized by Montgomery in 1929.1 The eponymic title was derived from cases presented by Borst in 19042 and Jadassohn in 1926.3 Actually, Borst's case was an example of intraepidermal spread of an invasive cancer of the lower lip and represented quite a different lesion from what is commonly included under this title today. Jadassohn's cases included one of intraepidermal basal-cell epithelioma and another which he interpreted to be an
GOLTZ RW, FUSARO RM, SWEITZER SE. Borst-Jadassohn EpitheliomaA Reevaluation. AMA Arch Derm. 1957;75(1):117–122. doi:10.1001/archderm.1957.01550130119014