[Basal lamina with a garland-like pattern in a case of sclero-atrophic lichen. Ultrastructural study].

The basal lamina stands at the heart of dermal-epidermal interactions. Its formation and pathology are more or less directly related to the basal keratinocytes, so that any lesion of these cells, such as vacuolar alterations of the interface, results in pathological changes in the basal lamina. Images of rupture, discontinuities, multiplications, festooning and budding of the basal lamina have been reported in psoriasis, lichen planus, lupus erythematosus and lichen sclerosus and atrophicus. We present a case of lichen sclerosus and atrophicus of the glans penis. Histopathological examination was performed, using the routine technique, the semi-thin large area sections technique and electron microscopy. Histological changes in the basal lamina were particularly pronounced, with garlands penetrating deeply into the dermis. Electron microscopy showed that the basal lamina contained immature collagen fibres, but no anchoring fibres. This garland-like pattern undoubtedly represents an extreme degree of the festooning and budding classically described in the diseases listed above. A pathogenic theory is offered to explain the formation of that pattern.