PMC5312190_01
A) Nodule with dark blue homogeneous pigmentation,
symmetrical and regular borders, measuring 2.5 cm in diameter on
gluteus; B) Dermoscopy exhibited a homogeneous and
structureless pigment pattern of grayish-brown color, more evident in
the follicular ostia
abd-92-01-0110-gf01.jpg
PMC5312190_01_abd-92-01-0110-gf01.jpg
f1
Physical examination revealed a dark blue nodule with homogeneous pigmentation, symmetrical and regular borders, with 2.5 cm in diameter on the left gluteus, with no palpable lymph nodes (Figure 1A). Dermoscopy revealed a homogeneous and structureless pigment pattern of grayish-brown color, and a slightly irregular surface (Figure 1B).
Melanocyte proliferation occupying papillar and reticular dermis, and
forming nests; no alteration in the epidermis was observed (Hematoxylin
& eosin x40)
abd-92-01-0110-gf02.jpg
PMC5312190_01_abd-92-01-0110-gf02.jpg
f2
Histological examination revealed a solid melanocytic lesion, composed by hypercellular nests affecting the entire dermis and part of subcutaneous tissue (Figure 2).
Nests compose of heavily pigmented and dendritic melanocytes in the
periphery; pale and ovoid melanocytes of intermediate size in the center
were consistent with cellular blue nevus (Hematoxylin & eosin
x100)
abd-92-01-0110-gf03.jpg
PMC5312190_01_abd-92-01-0110-gf03.jpg
f3
In the nest extremity, there were dendritic pigmented cells; in the center, ovoid and pale cells, with intermediate size; and focally, pleomorphic and vesicular nuclei, evident nucleoli, and occasional mitosis <2/mm2, which was compatible with ACBN (Figures 3 and 4).
Pleomorphic and vesicular nuclei, evident nucleoli, and occasional
mitosis (<2/mm2) were compatible with atypical cellular
blue nevus (Hematoxylin & eosin x400)
abd-92-01-0110-gf04.jpg
PMC5312190_01_abd-92-01-0110-gf04.jpg
f4
In the nest extremity, there were dendritic pigmented cells; in the center, ovoid and pale cells, with intermediate size; and focally, pleomorphic and vesicular nuclei, evident nucleoli, and occasional mitosis <2/mm2, which was compatible with ACBN (Figures 3 and 4).