Antiproliferative effect of hyperthermia and ACNU on cultured human malignant melanoma cells

Human malignant melanoma cultured cells were treated either with ACNU (1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chlorethyl)-3-nitro sourea hydrochloride), hyperthermia, or the combination of ACNU and hyperthermia. The combination treatment inhibited the cell growth to a slightly synergistic degree compared to the respective single treatments. The present in vitro experimental results support in part the finding of our previous report that the combination treatment with ACNU and hyperthermia have a significantly synergistic antitumor effect to human melanoma transplanted to nude mice. However, the synergistic effect was much less intense in the present in vitro experiment. The difference may have resulted from the environmental differences between in vitro and in vivo experimental systems.     

Osteosarcomatous changes in malignant melanoma. Immunohistochemical and ultrastructural studies of a case

Immunohistochemical and ultrastructural studies were conducted to elucidate the nature and origin of osteosarcomatous changes in malignant melanoma in a 43-year-old Japanese man. Immunohistochemical studies with the use of antisera against human S-100 protein and neuron-specific enolase demonstrated positive reactions in the tumor cells within the osteosarcomatous area. Ultrastructurally, the neoplastic cells showed marked similarities to those from osteosarcomas. Additionally, occasional neoplastic cells contained round or ellipsoidal osmiophilic organelles, presumably melanosomes. These findings indicate that osteosarcomatous changes in malignant melanoma are produced by the dedifferentiated melanoma cells.     

Atypical Melanosis of the Foot

We present a case of a seemingly malignant pigmented lesion on the foot, arising in a Japanese female. Clinically, the lesion was characterized by irregular borders and variegated pigmentation closely mimicking those of acral lentiginous melanoma in situ. However, the histologic findings revealed only focal, slight, melanocytic hyperplasia with minimal cytologic atypia along the basal layer. Despite the malignant clinical features, thorough histologic examination failed to disclose any area with significant melanocytic atypia or evidence of malignancy. To the best of our knowledge, no similar lesions with the clinical appearance of melanoma in situ and completely lacking histologic evidence of malignancy have been reported. We, therefore, prefer to designate this lesion as atypical melanosis of the foot, to highlight the clinically atypical findings and to distinguish this from malignant melanoma in situ of the foot (1).     

The Coexistence of Psoriasis Vulgaris,Sjögren's Syndrome,and Hashimoto's Thyroiditis

A 52-year-old woman presented with psoriasis vulgaris, Sjögren's syndrome, and Hashimoto's thyroiditis with a 5-year history. She had a number of immunological abnormalities and typical psoriatic plaques over her entire body. The relationship between psoriasis, Sjögren's syndrome, and Hashimoto's thyroiditis is discussed from the viewpoint of immunology, and similar cases in the literature are reviewed. This is the first report of a coexistence of psoriasis vulgaris, Sjögren's syndrome, and Hashimoto's thyroiditis.     

Desmoplastic malignant melanoma--an electron microscopic and immunohistochemical study of a case

A 86-year-old Japanese woman presented with an amelanotic tumor that had arisen on an antecedent pigmented lesion (acral lentiginous melanoma) on the lateral side of her right foot. The bulk of the tumor was composed of atypical spidle cells in a fibrous or myxoid matrix, pathognomonic of desmoplastic malignant melanoma. Immunohistochemically, neoplastic cells were positive for S-100 protein and neuron specific enolase. Ultrastructurally, the majority of spindle cells showed Schwannian features and contained no melanosomes. Occasional atypical cells, however, contained ellipsoidal organelles with subtle cross internal striations but did not show Schwannian features. Our findings lend further support to the hypothesis that the desmoplasia in desmoplastic malignant melanoma is the result of acquired fibrogenetic capacities of dedifferentiated melanoma cells.     

A Case of Giant Cell Tumor of the Tendon Sheath Developing on the Palm

A 22-year-old Japanese woman with a giant cell tumor of the tendon sheath on the palm is described. The location of the tumor is rare. Light microscopically, the tumor consisted of round or polygonal cells, giant cells, and foam cells. Electron microscopically, histiocyte-like cells and fibroblast-like cells were mainly observed, suggesting that the tumor may have originated from the synovial membrane.