c23t3P3 (case 6): The epidermis is hyperplastic with elongation of rete ridges. Lentiginous and junctional patterns are represented. Some of the atypical cells individually have migrated upward; the degree of atypia is moderately severe. In the junctional nests, cells are spindle shaped and have dendritic processes; they are variably pigmented. Thin, short fascicles of cells rain down into the dermis. They extend through a widened papillary dermis into the reticular dermis among collagen bundles. In the reticular dermis, some of the cells individually infiltrate among the collagen bundles. In the nests near the dermal-epidermal interface, the cells are loosely attached to their neighbors. Inflammation is not a prominent feature. The tumor does not induce a specific stroma in the reticular dermis. The patterns are Spitz nevus-like but the cytologic features are not. There is evidence of maturation. Would the observer accept this lesion as a variant of a “Spitz nevus?” Might it be better characterized as “spitzoid melanoma” (whatever that might be)? Is it MDM of Spitz-like type? Is it simply a “nevoid melanoma?” Is it MDM of pigmented spindle cell type (i.e., non-Spitz type; pigmented epithelioid melanocytoma type)? Good luck. If you err in the diagnosis of such a lesion, you may find yourself the recipient of a claim of malpractice from the state.

c23t3P4: Thin fascicles of atypical cells with minor “epithelioid” qualities from the epidermis into the altered papillary dermis. The cells of the nests are loosely attached to their neighbors. Nuclear chromatin is dense. Inflammation and classic lamellar fibrosis are not features.

c23t3P5: Are these atypical cells acceptable in the observer’s collection of virtual images as representative of a Spitz nevus. Are the features, in toto, representative of a common melanoma or even a variant melanoma such as nevoid melanoma?

c23t3P6: This is a migrant vertical growth-like pattern; it shares features with the migrant vertical growth-like features of the component in the reticular dermis in many “classic Spitz nevi.” The nuclei show dense chromatin patterns. In this field, the cells have induced a mucinous stroma among the collagen bundles of the reticular dermis. There is nuclear pleomorphism.