Histopathologic examination showed a well-circumscribed area located within the reticular dermis and composed of monomorphic spindle cells in intersecting fascicles that were aligned parallel to the epidermis. The spindle-shaped cells had plump nuclei and prominent nucleoli. Occasional mitoses were seen. Elastic fibers were absent. There was a patchy chronic inflammatory cell infiltrate in a perivascular distribution in the deep dermis. The lesion extended to the epidermis, which appeared atrophic but showed no specific features.
Nodule on the Shoulder of a Young Woman. Arch Dermatol. 2002;138(11):1509. doi:10.1001/archderm.138.11.1509