F1Ch27 (G5357): This is a classic configuration for a tricholemmoma; the vertical dimension is equal to, or greater than, the horizontal dimensions. There is prominent papillomatosis with hyperkeratosis. If we accept the crevices between the epithelial papillae as the equivalent of the ostia of hair follicles, there is a confluence of the epithelial components just beneath the papillae. There is a broad columnar extension that forms the terminus of the lesion. The pallor of the squamous epithelium, in part, is evidence that the section has faded; in addition, pallor is contributed by cytoplasmic vacuolization of many of the cells. There is a striking hyperplasia of sebaceous glands beneath the hair sheath component. It is difficult to dismiss an association between the sebaceous glands and the hair sheath component.
|