Ultrastructural studies on two cases of porokeratosis of Mibelli

Abstract

SUMMARY The ultrastructural features of two cases of porokeratosis of Mibelli are described. They demonstrate that the basophilic granular material in the cornoid lamella consists of whole degenerate cells with pyknotic nuclei. The dermis contains clumps of a finely fibrillar material and some collagen, and many fibroblasts show degenerative changes.

Disseminated Porokeratosis Mibelli Treated with RO 10-9359

“…10th day biopsies showed the picture already described by other authors [5,15,16]: the basal lamina showed numerous replications with branching projections; many prickle cells and granular cells showed large autophagosomes and vacuoles containing cellular debris and small dense granules; sometimes vacuolization was so serious that only few thin cytoplasm strands connected the nucleus with the cell membrane. Dyskeratotic (fibrous) cells were also commonly observed.…”

Hyperkeratotic Form of Porokeratosis Mibelli

“…Between the fine structures of this case with a hyperkeratotic form, and those of classic porokeratosis Mibelli and DSAP [17,21] there are some differences. In the latter group, although fibrillar bodies were present, type 1 fibrous cells were very rarely present and mitotic figures appeared normal.…”

Generalized Eruptive Porokeratosis of Mibelli with Associated Psoriasis

“…This limited involvement of the column of cells consisting of perinuelear poekets of eytoplasmie debris was verified by ultrastructural studies (Mann et al 1974). This limited involvement of the column of cells consisting of perinuelear poekets of eytoplasmie debris was verified by ultrastructural studies (Mann et al 1974).…”

“…It is of interest that Mikhail & Wertheimer (1968) noted the histologic similarity between the eells of the eornoid lamellae seen in porokeratosis with the eorps ronds and grains seen in Darier's disease. The sharply limited degenerative ehanges of both the epidermis and the dermis seen by electron microseopy (Mann et al 1974) perhaps ex-press an underlying enzymatie or biochemical defect allowing lytic changes to occur. The sharply limited degenerative ehanges of both the epidermis and the dermis seen by electron microseopy (Mann et al 1974) perhaps ex-press an underlying enzymatie or biochemical defect allowing lytic changes to occur.…”