Recurrent melanocytic nevi: Clinical and histologic review of 175 cases

Recurrent nevus phenomenon: a clinicopathologic study of 357 cases and histologic comparison with melanoma with regression

“…The time to recurrence was less than 6 months for over 64% of cases, with only 4% recurring after 24 months following the primary biopsy/excision. These findings are similar to those reported by Park et al, 6 with the exception of fewer head and neck cases seen in our series (28 versus 6%).…”

“…Dermal nests of melanocytes occurred in a significant number of cases (151 biopsies, 42%), similar to that seen in the study by Park et al 6 In their study, they observed what they term 'dropping off' of epidermal nevus cells into the dermis in 36% of their cases. Interestingly, in their study, nine of their recurrent nevi cases were purely intradermal, a finding not seen in our study.…”

“…The majority of our cases (85%) showed epidermal effacement with either a junctional or compound melanocytic proliferation, a pattern most commonly illustrated in prior publications, [1][2][3][4][6][7][8][9][10][11] and often showing pagetoid upward migration of melanocytes. In our series, it was this histologic pattern that showed pagetoid spread in 13% of cases (as opposed to 1% of cases of recurrent nevi with retiform epidermis).…”

“…This may become an increasingly important issue in view of the fragmentation of the health care system and the shipping of specimens to laboratories around the country. Various theories have been proposed regarding the origin of recurrent nevi, and these include melanocytes repopulating from the adjacent epidermis, 2,8 repopulation from adnexal structures 6,9 and regrowth from residual dermal nevus. 12 In 80 cases in our series, the primary lesion appeared to be completely excised, which would suggest that the regrowth from residual nevus was unlikely.…”

The essence of senescence: Figure 1.

“…Indeed, activation of senescence-abrogating pathways can be seen in melanomas clonally emerging from melanocytic nevi, which carry the same driver mutation (LCW Vredeveld and DS Peeper, unpubl.). Notably, wound healing can create a microenvironment that induces regrowth in nevi (Schoenfeld and Pinkus 1958;Park et al 1987). It will be of interest to identify the signaling pathways that apparently relax the cytostatic constraints.…”