Shin-Ichi Masu

Pigmentary incontinence in fixed drug eruptions: Histologic and electron microscopic findings

Pigmentary incontinence is a phenomenon observed in some inflammatory skin disorders. Clinically it may be seen as a slate-colored pigmentation. Histologically it is seen as an accumulation of melanin in the upper dermis. The possible mechanism for development of pigmentary incontinence is discussed based on a review of the literature and electron microscopic studies of fixed drug eruption.

A case of lichen amyloidosus with Riehl's melanosis-like lesion on the face: a histological and electron microscopic study of Civatte body and amyloid.

Ultrastructural studies were carried out on the patient who developed lichen amyloidosus and Riehls melanosis‐like lesion on the legs and face, respectively. In the skin specimens from the face, there were many masses of aggregations of wavy or net‐like filaments which appeared to correspond to Civatte bodies as recognized under the light microscope at the dermo‐epidermal junction. Sometimes, an other kind of filament mass was present in the papilla. These were aggregations of straight and non‐branching filaments and were very similar to so‐called amyloid masses. These amyloid‐like masses, which seemed to be in a developmental stage, consisted of net‐like filaments as well as straight and non‐branching filaments. Therefore, the net‐like filament masses or Civatte bodies seemed to serve a particular role in the formation of these amyloid‐like filament masses. On the other hand, in the skin specimens from the leg, there were many amyloid masses in the papillae and few Civatte bodies in the dermo‐epidermal junction, but no features suggesting that Civatte bodies may serve a role in the formation of amyloid. From these observations, it may be concluded that Civatte bodies will contribute to the formation of amyloid under certain conditions like Riehls melanosis; however, it is still uncertain whether Civatte bodies also contribute to the formation of amyloid filaments of lichen amyloidosus.

Electron microscopic studies of porokeratosis Mibelli --Civatte bodies and amyloid deposits in the dermis.

Electron microscopic investigations of lesions from 5 cases of porokeratosis Mibelli clarified that the cornoid lamella was composed of two types of abnormal horny cells, the precursors of which were detected as dyskeratotic cells and autolytic cells in the epidermis directly beneath the cornoid lamella. Therefore, it was concluded that the cornoid lamella might be caused by a disturbance of keratinization of genetically fragile keratinocytes. On the other hand, some sort of repair mechanism might be present in the epidermis of the lesion by which degenerated epidermal cells (Civatte bodies) are transferred from the epidermis into the cutis. In the cutis of the lesion, Civatte bodies were found in one case and amyloid in three cases. However, neither the coexistence of both nor an intermediate form was detected. These findings strongly suggest a possible conversion of Civatte bodies into amyloid.

CLINICAL FEATURES AND AN ULTRASTRUCTURAL STUDY OF EHLERS‐DANLOS SYNDROME TYPE II

Histopathological and ultrastructural studies were carried out on a case of a 4‐year‐old boy with type II Ehlers‐Danlos Syndrome. The patient showed velvety skin, hyperelasticity of the skin, and mild hypermobility of the joints. Histopathologically, numerous very fine collagen fibers were observed in the dermis, and no recognisable group substance was found. Ultrastructurally, abnormal collagen fibrils with irregular profiles were interspersed in the reticular dermis. However, their periodic band pattern was that of normal skin collagen. It is supposed that these abnormalities of fibrils are due to abnormalities of collagen fibrillogenesis.

IMMUNOFLUORESCENCE CHARACTERISTICS AND SOME BIOCHEMICAL PROPERTIES OF LARGE MOLECULAR WEIGHT KERATIN FROM HUMAN PLANTAR STRATUM CORNEUM

Keratin subunits of 64K, 53K, and 43K M.W. from human plantar stratum corneum fibrous proteins were isolated by SDS polyacrylamide gel electrophoresis (PAGE), and the antiserum against each keratin was prepared from rabbits. During indirect immunofluorescence studies of the normal skin, the whole epidermis stained positively with anti‐64K keratin antiserum (64K antiserum), but the positive staining of the basal layer diminished with the dilution of the antiserum. A similar staining pattern was observed with 53K antiserum, although the diminished staining of the basal layer was much less obvious than that with 64K antiserum. In contrast, 43K keratin was distributed throughout the whole epidermis including the basal layer, and no diminished staining with dilution of the antiserum was observed. These results suggest that an immunofluorescence technique using anti‐large M.W. keratin antisera, especially 64K antiserum with a certain degree of dilution, could be used to study the differentiated cells of the epidermis.