Sclerosing Nevus with Pseudomelanomatous Features (Nevus with Regression-Like Fibrosis): Clinical and Dermoscopic Features of a Recently Characterized Histopathologic Entity

Abstract

Background: Sclerosing nevi with pseudomelanomatous features or, else, nevi with regression-like fibrosis (NRLF) are histopathologic simulators of regressing melanoma. Objective: We aimed at evaluating the clinical features in a series of NRLF. Methods: Dermoscopic images of NRLF were re-evaluated according to the amount of regression, the presence of white/blue areas and the 7-point checklist. Results: Forty-six lesions from 44 patients (M:F = 3.4:1; mean age: 42 years) were evaluated. Thirty-seven lesions were excised from the back, mostly from the scapular area. All the lesions were dermoscopically atypical, with large amounts of regression (>10% in 43 cases) and with coexistence of white and blue areas (41 cases). According to the 7-point checklist, 25 lesions were labeled as benign, probably because regression obscured other dermoscopic features of atypia. Conclusion: NRLF are mostly found in the convex area of the back. A better recognition of their clinicopathologic features can allow a more conservative management.

“Clark/dysplastic” nevi with florid fibroplasia associated with pseudomelanomatous features

“…Recurrent nevi were originally described as ''pseudomelanoma'' because of the striking histopathologic resemblance of some examples to melanoma. [9][10][11] In recurrent nevi, the regenerated epidermis, with a poorly developed rete pattern and (sometimes) poor adherence to the dermis, may be a major factor in the pathogenesis of this architectural pattern. 12 It seems likely that the presence of single melanocytes associated with a distorted or flattened rete ridge pattern in our cases is also due in large part to the underlying fibrosis and fibrosis-induced changes in melanocyte phenotype.…”

Dermoscopy of Pigmented Poromas

“…Generally, the dermoscopic findings of regression structures and blue-whitish veil remind dermoscopists of malignant melanoma or other malignant skin tumors, while it was reported that nevus with regression-like fibrosis showed regression structures and some coexisted with blue-whitish veil [10]. Regression structures and blue-whitish veil are not always associated with malignant skin tumors.…”

Abundance of the benign melanocytic universe: Dermoscopic–histopathological correlation in nevi

“…Sclerosing nevi with pseudomelanomatous features or nevi with regression‐like fibrosis present a recently classified entity simulating regressing melanoma induced by minor trauma on pre‐existing nevi . These nevi are typically found on the convex area of the back of young to middle‐aged men .…”

“…A typical trizonal pattern can be observed in histopathology: (i) atypical junctional proliferation and pagetoid spreading; (ii) atypical melanocytic nests within dermal sclerosis; and (iii) residual nevus tissue surrounding and within the cicatricial tissue. In contrast with regressing melanoma, sclerosing nevi with pseudomelanomatous features lack cytological atypia, dermal mitosis, necrosis, tumoral melanosis and nodules of atypical melanocytes . Dermoscopically, sclerosing nevi with pseudomelanomatous features present as atypical pigmented lesions showing often centrally located diffuse gray or white areas covering 10–50% of the lesion's surface (Fig.…”