PMC9289571_01
Polymorphous plaque, with flatter depigmented area and slightly raised pigmented area on the left side of the neck, suggesting melanoma or collision lesion.
CCID-15-1325-g0001.jpg
PMC9289571_01_CCID-15-1325-g0001.jpg
f0001
Closer examination revealed a black, approximately 1 cm x 1cm, triangular-shaped plaque, which was macular and hypopigmented on one half and nodular as well as pigmented on the other (Figure 1).
(A) Dermoscopy showing abrupt cut-off between areas of stronger and milder pigmentation. Blue-whitish veil, peppering, multicomponent pattern, suggesting melanoma, with milia-like cysts and pseudofollicular openings suggesting seborrheic keratosis. (B) containing marked up photo.
CCID-15-1325-g0002.jpg
PMC9289571_01_CCID-15-1325-g0002.jpg
f0002
On the right side, blue-white veil, milia like cysts (circle), comedo-like openings as in seborrheic keratosis (rectangle), at 6 O' clock thick pigmented lines around appendageal openings (arrows), which are sometimes called rhomboidal structures similar to those of lentigo maligna (Figure 2).
Histopathology, (HE x 40) with features of regression and absence of junctional activity (left side of image) and nests of elongated tumour cells at the dermoepidermal junction (right side of image).
CCID-15-1325-g0003.jpg
PMC9289571_01_CCID-15-1325-g0003.jpg
f0003
Histopathology (HE, 10x, Figure 3) shows an area of regression in the left part of the image (inflammatory infiltrate, which is predominantly lymphocytic and perivascular, encompassing also melanophages; some capillaries are newly formed; no "junctional activity" tumour cells can be identified, ie no residual tumor epidermal component is present).