Deeply Pigmented Macules on Cheek and Neck
Junctional melanocytic nevus is a type of benign acquired melanocytic nevi whose aetiopathogenesis is attributed to mutation in B-rapidly accelerated fibrosarcoma oncogene with a triggering role of ultraviolet rays. It shows melanocytic proliferation occurs at the dermoepidermal junction and clinically presents as brown/black, non-hairy macules mostly on arms, lower limbs, chest and back. Mature nevus become smaller and paler and form nests or cords. Dermoscopy may show globular, reticular or mixed pattern but mixed central pattern is more common in young individuals. On histopathology, junctional nevi demonstrate the presence of theques of melanocytes at dermoepidermal junction. It should always be differentiated from compound and dermal melanocytic nevus. Surgical excision is the best treatment. A 12-year-old boy had an asymptomatic brownish-black macule on his neck. Diagnosis of junctional melanocytic nevus was made by dermoscopy and histopathology which demonstrated mixed central pattern and melanocytic nests at the dermoepidermal junction, respectively.
KeywordsJunctional Melanocytic nevi Theques
- 1.Newton-Bishop JA. Melanocytic naevi and melanoma. In: Hoeger PH, Yan AC, editors. Harper’s textbook of pediatric dermatology. 3rd ed. Oxford: Wiley-Blackwell; 2011. p. 1242–3.Google Scholar