Digital papular calcific elastosis: A histopathological, histochemical and ultrastructural study of 20 patients
In 1960, 5 patients were reported with a condition termed 'degenerative collagenous plaques of the hands'. Ultraviolet light and chronic pressure seem to be the inciting factors. Clinically, it is characterized by keratotic, translucent papules, in linear array, on the radial border of the hands. Histology shows hyperkeratosis and dermal elastosis. The current study documented the histopathological, histochemical and ultrastructural features of 20 patients with this condition and considered the differential diagnoses. The findings were in accordance with those of previous studies, bu peculiar, basophilic elastotic masses (BEMs), were a prominent finding. Ultrastructurally, elastic tissue appeared in the form of degenerated non-fragmented and fragmented elastic fibres, degenerated fibres showing foci of increased density, with or without a fibrillar component and as amorphous, structureless material. BEMs arose almost exclusively from degenerated elastic tissue and contained calcium. Disintegrated collagen may be incorporated in the amorphous material and, subsequently, form a minor part of BEMs. Solar elastosis, and its variants, show some similarity to degenerative collagenous plaques of the hands, but lack the constant presence of these calcified angular elastotic masses. BEMs show resemblance to elastic globes, and elastotic bodies found in elastotic nodules of the anthelix and cartilage-hair hypoplasia. In the clinical setting of 'degenerative collagenous plaques of the hands', BEMs seem to be unique and due to their extensive presence serve as a non-specific marker for this condition. Digital papular calcific elastosis therefore seems to be more appropriate nomenclature.