[Histologic criteria for the diagnosis of superficially spreading melanoma in patients with proven metastases].

The majority of authors agree that the prognosis of malignant melanoma depends on the depth of extension of malignant melanocytes into the dermis. A number of studies were performed to determine histologic characteristics of primary malignant melanoma that already metastasized. Their goal was to predict the biological behaviour of malignant melanoma by the histological picture. The study was designed to establish histological characteristics of superficial spreading melanoma. To prove the malignant biological behaviour, only superficial spreading melanomas with metastases in lymph nodes were analysed. The aim of the study was to see whether the melanoma's biological behaviour could be predicted on the basis of its histological picture. A total of 39 cases of superficially spreading malignant melanoma from the Department of Pathology, University Hospital Center Rebro, Zagreb, were analysed. The sections were taken from 5 different places, fixed in 10% purified formalin, paraffin embedded and stained with hematoxylin-eosin. In some cases the sections were additionally stained with Fontana to prove melanin. The sections were analysed by light microscopy. The following histological characteristics were analysed: 1. poor circumscription of the intraepidermal melanocytes; 2. individual melanocytes extending laterally; 3. number of atypical melanocytes above the basal membrane; 4. marked variation in the size and shape of melanocytic nests; 5. tendency of melanocytic nests towards confluence; 6. presence of melanocytes with nuclear atypia; 7. absence of maturation of melanocytes with descent into the dermis; 8. intradermal necrosis and degeneration of melanocytes; 9. lymphocytic infiltrate; 10. desmoplasia and ulceration. There were 22 male (56.4%) and 17 female (43.6%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)