c21t3P1 (case 4, continued): This is a continuation of the case represented on Chapter 19. The deep margin is represented. Thin fascicles infiltrate the reticular dermis on the right. Inflammation is not a feature; the lesion has organoid qualities. A column of nests of tumor cells extend along a widened perifollicular sheath into the dermis to the deep margin of the field; this type of perifollicular extension is a common feature of some “nevi,” particularly Spitz variants. It is also a feature of some pigmented spindle cell lesions.

c21t3P2: The interface with the reticular dermis is quiescent; there is no evidence of tumor stroma or inflammation.

c21t3P3: Pigmentation is variable from nest to nest near the dermal-epidermal interface. There is mild to moderate nuclear atypia; chromatin is dense.

c21t3P4: Nuclear atypia is moderate; nuclear characteristics are fairly uniform. Some of the nuclei show stippled chromatin and a small central nucleolus. There is a mitotic figure in the center of the field. Cells are loosely attached to their neighbors. The cells have prominent dendrites. Are the cytologic features those of a Spitz variant or a pigmented spindle cell (non-Spitz) variant?

c21t3P5: Atypia is more pronounced in this field. Nuclei are enlarged and have stippled chromatin. Nucleoli are variable. There are two mitotic figures.

c21t3P6: If comparisons are made with ocular melanomas, the degree of atypia in this field is beyond the Type A category. Nuclear membranes are uniform in thickness.

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