c22t3P1 (case 5): The epidermis is hyperplastic. There are focal, poorly developed lentiginous patterns. Near the left margin, blue arrows identify several nests of small, pale epithelioid cells; the nests are loosely spaced in a widened papillary dermis showing laminated patterns. To the right of the center of the field, blue arrows identify a nodular zone of sclerosis, again with laminated collagen bundles.  Atypical, small, epithelioid tumor cells are individually isolated in the fibrous matrix; the patterns are “desmoplastic” but I would prefer to characterize the pattern as sclerosing vertical growth-like. Vessels are ectatic.

GENERAL INDEX

c22t3P2: At one margin, lentiginous and junctional patterns are represented. Atypia is moderate to moderately severe. The cells of the junctional nests are spindle shaped and dendritic in outline; they are loosely attached to their neighbors. The papillary dermis shows lamellar fibrosis. Currently, the basic pattern of this field (without attention to cytologic details) could be accommodated in the category of “junctional Spitz nevus.” There are mild perivascular infiltrates of lymphoid cells in the dermis. The basic patterns could also be accommodated in the category of a premalignant melanocytic dysplasia - as such, the pattern might also be representative of the radial growth component of some type of melanoma (having set aside the dictum that there is “one melanoma”).

c22t3P6: The nests of cells infiltrate the reticular dermis among collagen bundles without inducing a significant stromal response; the pattern qualifies as migrant vertical growth-like; if the observer accepts this lesion as a melanoma, then the pattern is migrant vertical growth. Inflammation is not a feature. Lentiginous and junctional patterns are not a feature; the lesion is dermal in this field, but may be a variation related to the site selected for sampling. There is on “nevus-like” giant cell of the type that some observers characterize as “touton type.” Does the combination of features qualify the lesion as a sclerosing or dermal variant of “Spitz nevus?” There is cytologic atypia of a type seen in several variants of MDM.

c22t3P7: In this field, the nests of tumor cells have induced a reactive stroma. The nests are loosely spaced but, in this restricted field, perhaps it is sufficient to characterize the pattern as variant vertical growth-like. Degree of atypia is moderate. The atypical cells show slight variations in nuclear size and staining; some of the nuclei show central nucleoli. Inflammation is not a feature. The cytologic features are of a type commonly seen in MDM.

c22t3P8: Collagen bundles of the reticular dermis are entrapped among the nests of atypical cells; the nests are uniformly small and rounded; inflammation is not a feature. The pattern is level IV and is migrant vertical growth-like. The cells have “epithelioid” qualities. Nuclear atypia is moderate to moderately severe.