Longitudinal Melanonychia—Quiz Case

Nail Unit Blue Nevi: A 11-Case Series and Review of the Literature

“…Nevertheless, blue nevi are presumably linked to a failure of embryonic migration that could explain this unusual location. In the literature, 5 cases of nail unit blue nevi were reported with LM [10, 19-22]. Except for the case of Causeret et al [10] who described typical multiple ethnic melanonychia striata, the other authors did not offer any explanation concerning these melanonychia.…”

Longitudinal melanonychia of the toenails with presence of Medlar bodies on biopsy

“…Causes of longitudinal melanonychia are myriad (Table 1). 9–27 There is a racial predilection, with multiple pigmented nail streaks being commonly seen in darker pigmented races. In children, a review of 40 cases of longitudinal melanonychia revealed that 48% were caused by a matrical nevus (most often junctional), 30% were secondary to melanocytic hyperplasia, and 22% were a result of increased melanocytic activity 28 .…”

Subungual blue nevus

“…Of the 12 case reports of subungual blue nevi found in the English literature with well-described pathologic characterization from 1985 to present, ten were from patients under the age of 60, with four of those patients reported having the lesions since childhood or birth. [5][6][7][8][9][10][11][12][13][14][15][16][17] Of the two cases in patients over the age of 60, the lesions had been present for three years or less, highlighting that nevi may be acquired later in life infrequently. Nine of the 12 cases occurred in women.…”

“…Based upon our assessment of the clinical images in each report, all of the patients ranged on the Fitzpatrick scale from I to IV. Nine of the cases were associated with pigmentary changes, which included longitudinal melanonychia and scattered pigmented streaks 5,9,13,14,16 and structural changes such as dystrophy, erosion, brittleness or pseudo-clubbing. 6,7,11,12,17 Common blue nevi were the most frequently described subtypes, followed by the cellular and combined variants ( Table 1).…”