Disseminated bilateral hyperkeratotic variant of porokeratosis Mibelli

Abstract

Clinical, histopathological, and ultrastructural features of a new clinical variant of porokeratosis Mibelli (PM) are presented. We report a solitary case of a patient, male aged 62, who developed disseminated verrucous nodules on the buttocks and the lower extremities 3 years before diagnosis. Histopathologically, all specific signs of the keratinization disorder of PM were demonstrable; in addition, however, multiple cornoid lamellae were found at the margin as well as in the center of the lesions, which only in part showed relationships to the epidermal appendages. In the papillary dermis, numerous ectatic capillaries were conspicuous. Using electron microscopy the same specific abnormalities of the keratinization process as known from classical cases of PM could be demonstrated: autophagocytic cells that revealed perinuclear edematization and vacuolization, accumulation of autophagic vacuoles and heterolysosomes, and dyskeratotic corps ronds-like cells that become transformed to fibrillar or Civatte bodies. Problems of the classification, differential diagnosis, and pathomorphogenesis are discussed.

The Hyperkeratotic Variant of Porokeratosis Mibelli Is a Distinct Entity: Clinical and Ultrastructural Evidence

“…However, histopathological sections reveal only one cornoid lamella located at the mar gin of each hyperkeratotic lesion. Our ultrastructural investigations also demonstrate the two typical alterations of the keratinocytes, which were described before by Sato et al [ 12] and Marghescu et al [13]. The ultrastructural morphology of the dyskeratotic cell type is comparable to aberrant kera tinocytes typically found in Darier's disease.…”

“…The clinical aspect of our patient is simi lar to the one presented by Marghescu et al [13] and Jacyk and Esplin [14]. Also in our histopathological studies multiple dilated vessels in the upper dermis are obvious.…”

“…The third solitary case was described by Marghescu et al [13] in 1987. Their patient, a man aged 62 years, had developed dissemi nated verrucous nodules on the buttocks and the lower extremities 3 years before diagno sis.…”

“…On the ultrastructural level two different types of aberrant keratinocytes were demonstrated similar to the two 'fibrous cell' types of Sato et al [12]: an autophagocy totic cell type which seems to be highly spe cific for porokeratosis and a more unspecific dyskeratotic cell type. Marghescu et al [13] distinguished their observation from the pre viously reported cases of classical PM and of other variants of porokeratosis by the clini cal, histopathological and ultrastructural pe culiarities. Their patient showed a symme trical bilateral dissemination of verrucous nodules mainly on the lower extremities, a late manifestation of the disease and no rele vant family history.…”

Familial disseminated plaque type porokeratosis with multiple horns and squamous cell carcinoma involving anal skin

“…[1,5] The concomitant presence of different clinical patterns in a single case has been found repeatedly.…”