Case 49 Female, 61 years. Papule, skin of abdomen.Show diagnosis & comments
This exceptional case shows a basal, neurofibroma-like nodule, showing partial Melan-A positivity (not shown), arguing against fortuitous collision of neurofibroma and melanocytic naevus. Cases like this pose intriguing questions (but precious little answers) about the possible interrelationship between melanocytic and neural lesions. Note also the naevus cell nest bulging into the lumen of a lymph vessel within the upper part of the naevus (not an uncommon finding, and probably of relevance viz-à-viz the presence of naevus cell groups in some lymph nodes draining the skin).
Chen Y, Klonowski PW, Lind AC, Lu D. Differentiating neurotized melanocytic nevi from neurofibromas using Melan-A (MART-1) immunohistochemical stain. Arch Pathol Lab Med. 2012 Jul;136(7):810-5.