PMC5312189_01
Clinical picture showing the complete feature of NS, involving the
external aspect of the right arm and forearm of the patient. Three foci
of newly formed, irregular dark areas can be seen (lesions A, B, and
C)
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Examination revealed a 27 cm x 10 cm light tan patch with speckled lentiginous pigmentation involving the external aspect of his right arm and forearm (Figure 1).
Closer view of the lesions A, B, C and the irregular patch on the upper
back of the patient (lesion D)
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Three separate areas were observed within this larger lesion with a varied darker pigmentation and irregular borders: two maculopapules measuring 23 x 23 mm (lesion A) and 15 x 22 mm (lesion B), and one macule measuring 20 x 23 mm (lesion C) (Figure 2). D) (Figure 2). Dermatoscopic examination of the four suspicious lesions was highly suggestive of malignant melanoma (Figure 3).
Dermoscopy of the suspected lesions revealed blue-grey veils,
structureless areas, and irregular pigment network with black dots and
globules
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D) (Figure 2). Dermatoscopic examination of the four suspicious lesions was highly suggestive of malignant melanoma (Figure 3).
Histopathologic examination revealed that lesions A and B were invasive
superficial spreading melanomas, forming multiple irregular nests and
sheets in the dermis (A_Hematoxylin & eosin, x100, B_Hematoxylin
& eosin, x40). Histology of lesions C and D showed the
characteristics of in situ malignant melanoma (Hematoxylin & eosin
x100), with marked proliferation of atypical melanocytes along the
dermal-epidermal junction and superficial inflammatory infiltration of
the dermis
abd-92-01-0107-gf04.jpg
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On final pathology, lesions A and B were superficial spreading melanomas, with Breslow thicknesses 2.51 mm and 1.18 mm, respectively; lesions C and D were in situ malignant melanoma (Figure 4).
Histopathology of the nevus spilus showing mild acanthosis, elongation of
rete ridges, and lentiginous proliferation of basal melanocytes at the
dermoepidermal junction with hyperpigmentation of basal keratinocytes
(Hematoxylin & eosin x200)
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The intervening epidermis between the neoplastic foci was consistent with a background NS lesion (Figure 5).