Lymphatic invasion of nevus cells observed in intradermal nevus.

A pigmented nevus was observed on the medial aspect of the left scapula of a 30-year-old woman. Histologically, the lesion showed the pattern of a typical intradermal nevus, consisting of type A, B and C cells. However, the most characteristic feature of this intradermal nevus was the projection of polypoid masses of nevus cells containing melanin into the lumen of a lymphatic vessel in the upper dermis. To our knowledge, lymphatic invasion in pigmented nevi is rare; this finding is interesting, if we consider the relationship between nevus cells and lymph nodes.