Recently, microvascular channels, as detected by PAS histochemistry, were positively correlated with poor prognosis in uveal malignant melanoma. Since uveal melanomas are not penetrated by lymphatic vessels, while cutaneous melanomas are, the question arises as to whether these loops and networks are also of prognostic relevance in cutaneous melanoma. Histochemically and immunohistochemically detected loops and networks in 100 cases of cutaneous malignant melanoma were correlated with the occurrence of metastasis in a 10-year follow-up study. To detect these patterns, the significance of various methods (PAS reaction with/without nuclear counterstain, anti-laminin immunohistochemistry) was investigated. The presence of loops and networks was a highly significant prognostic marker (p
