No abstract

We observed age‐related changes in Meissner's corpuscles, one type of cutaneous sensory receptor, in subjects ranging from their 20s to their 70s. Nerve fibers in Meissner's corpuscles were observed by the silver impregnation technique. They changed morphologically with aging. Meissner's corpuscles are supplied by one to four myelinated nerve fibers, most frequently one or two, from the lower portion, and, most densely, from the basal portion. By morphometric analyses, the size of Meissner's corpuscles was found to increase with aging, but to decrease during the 70s. Furthermore, this size change depends upon the size of the lamellar cells in the direction of the long axis, and, among subjects in their 60s, in the direction of the short axis as well. The shape of Meissner's corpuscles becomes more complicated with age due to twisted alterations. This change occurs markedly during the 60s.

We studied the conversion of T. rubrum from hyphae to spherical cells using the agar‐implantation method. Thirteen cultures of T. rubrum were isolated from tinea superficialis and granuloma trichophyticum and they were implanted into the peritoneal cavities of ddY male mice. The cultures were divided into three groups according to their parasitic forms. The first group consisting of two cultures were isolated from tinea unguium and tinea pedis (hyperkeratotic type); they were destroyed in the peritoneal cavities of mice by the sixth week. The eight cultures in the second group were isolated from tinea cruris, tinea circinata and tinea pedis (vesicular type); they converted to spherical cells and survived for 16 weeks. The three cultures of the third group were isolated from granuloma trichophyticum; they survived and grew as hyphal forms in the peritoneal cavities of mice for over 26 weeks without spherical cell conversion. In conclusion, the parasitic forms of the three cultures isolated from granuloma trichophyticum differed from the cultures isolated from tinea superficialis.

A 59-year-old man visited our hospital. The patient had suffered from generalized tinea superficialis for thirty years, had been treated with several topical antifungal preparations and was administered griseofulvin at another hospital. Clinical manifestations were as follows: There were large pigmentations on the chest, abdomen, and lower extremities. He had several irregular shaped ulcers on the back, left forearm, and right axilla, and glossy granular lesions on the dorsum of the left foot. Generalized eruptions consisting of indurative pustules, red papules, scars, atrophies and depigmentations were also visible. The biopsy specimens taken from the ulcers, the indurative pustules and granular lesions of the dorsum of the left foot were cultured and Trichophyton rubrum was isolated. Laboratory studies showed slight eosinophilia, Mantoux reaction 56 X 40 mm, Trichophytin reaction 5 X 5 mm, IgE 4000 IU/dl. Histological findings were as follows: Fungal elements were observed in the horny layer, in the spindle cell layer, and in the dermis. Histologic features were both abscesses and granulomas with giant cells. According to the pathologic features of the lesions, the parasitic forms of the fungus changed. Abscesses and granulation tissues containing histiocytes and many multinucleated giant cells were observed in the dermis. Various sizes of arthrospores and various shapes of hyphae were stained by PAS. Most of these fungal elements dissolved in the abscesses and granulomas. However, a few survived.

A case of basal cell epithelioma (BCE) with multiple large nuclei on the right buttock of a 69-year-old woman is reported, and the skin was studied by light and electron microscopy. This represented the only case (0.85%) of giant tumor cells with multiple nuclei among 117 patients with BCE. Ultrastructural studies revealed that giant tumor cells were not different from ordinary tumor cells of BCE, except for large convoluted nuclei. In the cytoplasms of giant tumor cells, we observed autophagic vacuoles which were derived from autophagocytosis. Scattered among the giant tumor cells, there were many degenerate tumor cells, some of which were phagocytized by giant tumor cells with multiple nuclei (referred to as macrophagocytosis). It is indicated that tumor cells have considerable phagocytic activities, and degrade the autophagic vacuoles or the degenerate tumor cells with the lysosomes. These findings suggest that the presence of the giant tumor cells with multiple nuclei does not indicate a increased malignant potential or anaplasia of the tumor, and that autophagocytosis or macrophagocytosis is a factor in initiating giant tumor cell formation.