Abstract
Primary malignant melanoma of the vagina occurred in 4 patients who were under our care. The cytological and histological findings in these lesions are described. Papanicolaou smears were studied at 200 and 400 magnifications. In the latest case, malignant melanoma cells were examined consecutively with a light microscope (LM), a scanning electron microscope (SEM), and a transmission electron microscope (TEM).
1) No intranuclear vacuolation was found in any case. Mutual inclusion and intrahistiocytoplasmic melanin granules were demonstrated in only one case.
2) The cell arrangements were generally sporadic with occasional loose clusters.
3) The nuclei were horse-shoe shaped cells with irregular margins.
4) Cytometry revealed that the oval or spindle-shaped cells were small, 16.5 and 12.8μ on average in the major and minor diameters, respectively.
5) TEM examination of the malignant melanoma cells demonstrated the presence of melanosomes having diameters of 0.2-0.3μ.
From these findings, it was concluded that in the case of a tumor containing either oval or spindle-shaped cells which are small and arranged in such a way as to be intermediate between sarcoma and epithelial tumors, melanoma should be suspected even if no melanin granules are demonstrated. In addition, the LM-SEM-TEM technique used for exfoliative cytology seems to be a useful diagnostic method which can effectively demonstrate melanosomes in a place of a biopsy.
