MAST-CELLS IN MELANOCYTIC TUMORS

The importance of mast cells in local homeostasis, inflammation and tu mour surveillance is supported by many studies, and the association of mast cells with various neoplasms has been known for a long time. The functional significance of mast cells surrounding tumours is currentl y unclear. In the present histopathological study, 16 naevi and 44 pri mary malignant melanomas were analysed. The follow-up time after prima ry surgery of malignant melanoma patients was almost 10 years, during which time half of the tumours had metastasized. The numbers of mast c ells surrounding pigmented lesions were determined. The mast cells wer e visualized using a modified toluidine blue staining (pH 0.5; 24 h). Significantly different numbers of mast cells were found in naevi comp ared to melanomas (P = 0.0013), but no significant correlation could b e identified regarding prognostic parameters including tumour thicknes s and clinical outcome.