Vascular structures |
Diagnostic significance |
Comma vessels |
Mainly in melanocytic nevi, especially in dermal nevi; rarely in melanomas |
Wreath vessels |
Exclusively in sebaceous hyperplasias |
Arborizing vessels |
Commonly in basal cell carcinomas; rarely in nevi and melanomas and also in seborrheic keratoses |
Hairpin vessels |
Commonly in melanomas and seborrheic keratoses; sometimes also in basal cell carcinomas, keratoacanthomas and in melanocytic nevi |
Dotted vessels |
More or less common in all types of melanocytic tumors; sometimes also in seborrheic keratoses; rarely in basal-cell carcinomas |
Linear irregular vessels |
Relatively common in melanomas, especially when thicker than 0.75 mm; rare in melanocytic nevi |
Vessels within regression structures |
Frequently within white areas of regressive melanomas |