|LETTER TO EDITOR
|Year : 2014 | Volume
| Issue : 2 | Page : 102-103
Spontaneous regression of a medium sized congenital melanocytic nevus
María Mercedes Otero Rivas, Sonsoles Delgado Vicente, Luis Miguel Valladares Narganes, Elia Samaniego González
Department of Dermatology, Complejo Asistencial Universitario de León, C/Altos de Nava s/n CP: 24071, León, Spain
|Date of Web Publication||27-Aug-2014|
María Mercedes Otero Rivas
Department of Dermatology, Complejo Asistencial Universitario de León, C/Altos de Nava s/n CP: 24071, León
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Rivas MO, Vicente SD, Narganes LV, González ES. Spontaneous regression of a medium sized congenital melanocytic nevus. Indian J Paediatr Dermatol 2014;15:102-3
|How to cite this URL:|
Rivas MO, Vicente SD, Narganes LV, González ES. Spontaneous regression of a medium sized congenital melanocytic nevus. Indian J Paediatr Dermatol [serial online] 2014 [cited 2020 Feb 26];15:102-3. Available from: http://www.ijpd.in/text.asp?2014/15/2/102/139517
An otherwise healthy 15-year-old female patient was regularly followed in our Pediatric Dermatology Clinic since she was only 21 months of age because she presented an 8 × 3 cm. congenital melanocytic nevus (CMN) in her right upper limb. In the last visit, she claimed that the lesion had started to fade some months ago. On skin examination, a subtle peripheral loss of melanocytic pigmentation was observed. No halo or eczema was appreciated and the lesion remained asymptomatic [Figure 1]a]. In the area of pigmentation, dermoscopy showed coarse terminal hair and globules of pigment in a typical CMN fashion [Figure 1]b]. Meanwhile, the areas of regression showed whitish homogeneous areas [Figure 1]c]. On clinical and dermoscopic follow-up, the nevus is still undergoing these changes.
|Figure 1: (a) Congenital melanocytic nevus, note the central zone with pigmentation and the peripheral rim of normal colored skin; (b) Coarse terminal hair and globules of pigment without any atypical findings; (c) Whitish homogeneous regression in the depigmented area|
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We performed a skin biopsy under local anesthesia. The H and E stain showed a predominantly dermal benign melanocytic proliferation admixed with an intense lymphocytic infiltrate. There was no sign of concurrent spongiotic dermatitis in the dermoepidermal junction [Figure 2]a]. Under inmunohistochemical stains, these cells revealed as CD8+ lymphocytes [Figure 2]b].
|Figure 2: (a) H and E, (×4) nests of melanocytic nevus cells extending into the deep dermis around a hair follicle; (b) Admixed infiltrate of predominantly CD8+ lymphocytes|
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Given these findings we concluded that the nevus was undergoing a spontaneous regression which may be related either to an autoimmune process with melanocytic apoptosis or loss of melanin synthesis by the melanocytic cells.
Few cases have been reported of CMN with spontaneous regression without associated halo phenomenon (Sutton nevus) or eczema (Meyerson nevus). 
Sutton's nevus, also known as halo nevus or leukoderma adquisitum centrifugum, is a well-known phenomenon in acquired melanocytic nevus (around 1% in Caucasians), characterized by progressive lightening in a rounded, symmetric pattern. However, its occurrence in CMN is exceptional.  A dense infiltrate of predominantly CD8+ lymphocytes can be seen around the rests of a regressed melanocytic lesion.
Meyerson nevus is characterized by the presence of an eczematous dermatitis, with scaling and inflammation, around a melanocytic nevus. Histopathology shows a melanocytic lesion (congenital or acquired) with associated spongiotic dermatitis, without the involution of the former seen in halo nevus. Lymphocytic infiltrate is mainly composed of CD4+ lymphocytes.
Spontaneous regression of CMN is believed to express an autoimmune process that can be related to the destruction of melanocytic nevus cells or cessation of pigment production.  Melanocytic nevus cells express major histocompatibility complex class I antigens which allows recognition as a target for cytotoxic T cells. 
To conclude with, we present a case of spontaneous incomplete regression of a medium sized CMN. The differential diagnoses include halo nevus and Meyerson's phenomenon. Once excluded any atypical findings, no intervention is advised.
| References|| |
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|2.||Tokura Y, Yamanaka K, Wakita H, Kurokawa S, Horiguchi D, Usui A, et al. Halo congenital nevus undergoing spontaneous regression. Involvement of T-cell immunity in involution and presence of circulating anti-nevus cell IgM antibodies. Arch Dermatol 1994;130:1036-41. |
|3.||Martín JM, Jordá E, Calduch L, Alonso V, Revert A. Progressive depigmentation of a palmar congenital melanocytic nevus without an associated halo phenomenon. Dermatology 2006;212:198-9. |
|4.||Langer K, Konrad K. Congenital melanocytic nevi with halo phenomenon: Report of two cases and a review of the literature. J Dermatol Surg Oncol 1990;16:377-80. |
[Figure 1], [Figure 2]