Masahiko Ishihara

Distribution Density of Intraepidermal Nerve Fibers in Normal Human Skin

A total of 74 specimens was obtained from the normal human skin of patients from 3 to 90 years old. The specimens were roughly classified into 5 groups: 15 for the face group from the face; 15 for the abdomen group from the abdomen; 13 for the back group from the back; 14 for the arm group from the upper arm and forearm; and 17 for the leg group from the thigh and lower leg. They were all fixed in 4% paraformaldehyde and 14% saturated picric acid. Cryostat sections were examined by the immunoperoxidase method and indirect immunofluorescence (IF). Primary antibodies against neurofilament, neuron‐specific enolase, protein gene product 9.5 (PGP 9.5) and S‐100 protein were used. The most effective method was found to be the combination of IF with PGP 9.5; it visualized the intraepidermal nerve fibers easily and clearly. Of the 74 specimens, 32 (43%) had intraepidermal PGP 9.5‐immunoreactive (or nerve) fibers (IPIF), and 42 (57%) did not have any. With reference to the different skin locations, the maximal rate of specimens having IPIF was 57% in the arm group, and the minimum was 23% in the back group. IPIF positive specimens had approximate surface lengths of 6 mm, in which the existence number of the IPIF was 1 to 75. Their distribution density per 1000 epidermal basal cells was highest at 9.63 in the arm group and lowest at 2.89 in the back group. Their thickness was 2.94 ± 0.83 μm with no significant differences among the five groups. We concluded that intraepidermal nerve fibers may not be distributed evenly in the hairy portions of normal human skin, but they may be present focally. Physiologically, two‐point discrimination of itch may be explained by the distribution mode of intraepidermal nerve fibers.

Centrifugal lipodystrophy of the face mimicking progressive lipodystrophy

Summary We report a Japanese boy with centrifugal lipodystrophy. The initial lesion developed on the forehead as an area of erythema which showed centrifugal spread and central fading to leave a residual depression. Three years later, similar erythematous lesions appeared on the cheeks, and he developed a cadaverous appearance. A central depression on the upper trunk was surrounded by an erythematous border and there was right cervical lymphadenopathy. Histological examination revealed inflammatory changes in the subcutaneous fat. Although this patient showed the characteristics of both centrifugal and progressive lipodystrophy (partial lipodystrophy), we consider that he has centrifugal lipodystrophy of the face because of the overall features of the lesions.

A case of non-selective phagocytosis of hemosiderin and melanin of dermal histiocytes in stasis dermatitis.

A case study was undertaken to determine whether or not the same dermal histiocytes could phagocytose both melanin and hemosiderin simultaneously. A biopsy specimen was taken from a pigmented lesion of the lower leg of a 57-year-old woman with stasis dermatitis. The specimen was processed for histology, conventional transmission electron microscopy and electron-probe X-ray microanalysis. Histologically, numerous histiocytes with their cytoplasm packed with either Prussian blue-positive granules or Fontana-Masson-positive granules were distributed almost equally in the dermis. Electron microscopically, the dermis had many histiocytes with their cytoplasm containing solitary or compound electron-dense substances. The electron-dense substances were classified into three types according to their degree of electron density. By electron-probe X-ray microanalysis, these electron-dense substances were classified into iron-containing and non-iron-containing substances. Both substances were seen in the cytoplasm of the same histiocytes and even in the same compound electron-dense substance. The former were siderosomes and the latter were probably melanosomes. These results show that the same dermal histiocytes probably phagocytose non-selectively both hemosiderin and melanin granules.

Genital Paget's Disease: A Transmission‐, Scanning‐, and Immuno‐electron Microscopic Study

A case of genital Pagets disease examined by a transmission‐, scanning‐, and immuno‐electron microscopy was reported. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observations indicated that Paget cells had the characteristic features of glandular cells. In immunoelectron microscopy, carcinoembryonic antigen was found on the entire plasma membrane of Paget cells. Therefore, these observations may support the viewpoint that Paget cells are neoplasmic glandular cells.

Malignant melanoma. A case of malignant melanoma as genesis of nevocellular nevus.

A 39-year-old female presented with a rapidly enlarging and easily bleeding tumor on her right thigh. On physical examination, there was a 3×2.5cm, parallelogramatic, black and dark red tumor on the lateral portion of the right thigh. The tumor was radically excised with regional lymph nodes dissection, followed by receiving chemotherapy with DAV etc. Up to the present time, she has remained disease-free. Gross pathologically, the lesion consisted of a nodule and a flat-elevated part. Histopatho-logically, the nodule had central and bilateral portions. The former consisted of A-type-like cells similar to A-type of nevus cell nevus and B-type cells of the nevus cell nevus. There was gradual transition between them. The bilateral portions composed of highly atypical tumor cells showed expansive growth. The flat-elevated part consisted of A-type-like cells and spindle-shaped cells in the epidermis and the papillary dermis. Tumor cells of the regional lymph node metastasis had almost the same characteristics as those of A-type like cells. The tumor cells in local recurrence were mainly spindle-shaped.Immunohistochemistry showed common reactivity between A-type-like cells and tumor cells in the flat-elevated part, but the tumor cells in bilateral portion of the nodule had the characteristics different from those of A-type-like cells. These findings suggest that in this patient malignant melanoma arose from nevocytic cells in the dermis.