Pseudoglandular-type melanoma: a rare melanoma variant. 
We describe a 64-year-old man with a primary nodular melanoma showing unusual histologic features.  It consisted entirely of markedly atypical melanocytes arranged in a well-structured glandular pattern.  These atypical melanocytes were positive for S-100.  This is only the second report of such histology in melanoma, and to our knowledge, the first such case consisting entirely of these features.  We review the literature on this rare variant of melanoma.