PMC3125665_01
Dome-shaped tumor mass of the connective tissue separated from the surface epithelium by a band of collagen. The pigmented tumor is poorly circumscribed. H&E stain, 40x magnification
JOMFP-15-88-g001.jpg
PMC3125665_01_JOMFP-15-88-g001.jpg
F0001
Pigment production was most prominent among the superficial tumor cells, with those in the deeper tissues showing reduced intracytoplasmic pigmentation [Figure 1].
a) Coarse melanin granules obscure the epithelioid cell membranes. Intermingling of dense collagen bundles produces a checker board appearance. b) Epithelioid cells shown little pigmentation around the periphery of the cytoplasm. They also show a prominent nucleus and occasional dot-like nucleoli. The cell membranes are indistinct. H&E stain, 200x magnification
JOMFP-15-88-g002.jpg
PMC3125665_01_JOMFP-15-88-g002.jpg
F0002
While the pigment-producing large cells were largely obscured by the intracytoplasmic melanin, their nuclei remained fairly prominent[Figure 2a]. The nuclei showed intranuclear vacuolation with occasional pinpoint nucleoli[Figure 2b].