c16t3P3: Fascicles of short, plump spindle cells rain down into the widened, edematous papillary dermis. Thin fascicles extend into the reticular dermis among collagen bundles. Some of the cells in junctional nests are pigmented. In the junctional nests, the cells are loosely attached to their neighbors. The patterns are Spitz-like but there is cytologic deviation with atypia; nuclei vary in outlines; chromatin is dense. Is the pattern in the reticular dermis evidence of migrant vertical growth of a MDM or nevoid melanoma, or is it evidence of the dermal component of a “Spitz nevus” showing maturation?

c16t3P4: The neoplastic cells are spindle shaped. They have pale acidophilic cytoplasm; they show variations in nuclear outlines and are hyperchromatic. Cells of the fascicles are loosely spaced. In areas, lymphoid cells intermingle among the tumor cells.

This lesion poses problems in differential diagnosis; along with the taxonomic problems, the observer must entertain questions regarding the biologic potential of a lesion showing these patterns and this degree of atypia. Too little attention has been paid to atypia in the Spitz categories, but don’t be influenced by this caution. I have transferred responsibility to the observer.

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