Case 59 Female, 56 years. Pigmented papule, skin of backShow diagnosis & comments
Compound naevus with desmoplastic (Melan-A++) basal component
Micrographs to follow.
This naevus shows a basal spindle-cell desmoplastic component that is devoid of nuclear atypia and mitotic activity and is Melan-A positive, arguing against desmoplastic melanoma. Vexingly, some desmoplastic naevi exhibit perivascular lymphocytic aggregates, a feature they have in common with desmoplastic melanoma (reference: see below). This examples shows such lymphocytic aggregates in the desmoplastic component of the lesion.
Kiuru M, Patel RM, Busam KJ. Desmoplastic melanocytic nevi with lymphocytic aggregates. J Cutan Pathol. 2012; 39: 940-4.