Blue naevi of lymph node capsule.

Blue naevi are reported for what is believed to be the first time in the capsule and fibrous trabeculae of lymph nodes. In one of the two cases that nodal blue naevus was accompanied by an ordinary blue naevus in the regional skin. These blue naevi are compared with the 'naevus-cell aggregates' in nodal capsule, the histogenesis of which is currently disputed. A developmental migratory arrest of melanocytes is thought to be the histogenetic mechanism involved in the production of these blue naevi in lymph nodes.