Melanocytic Nevus with Atypical Dermoscopic Features at the Site of Radiodermatitis:

Dermoscopic Aspects of Traumatized Nevi After Dermabrasion

BACKGROUND

Melanocytic nevi submitted to trauma can undergo clinical, dermoscopic, and even histological changes, making it difficult to differentiate them from a melanoma.

OBJECTIVE

The aim of this study is to evaluate the dermoscopic changes of traumatized nevi after dermabrasion.

METHODS

Dermoscopic images of acquired melanocytic nevi were compared before and 4 weeks after half of their area had undergone dermabrasion.

RESULTS

The sample consisted of 50 lesions from 15 patients. The homogeneous pattern was the most frequent, followed by the reticular, cobblestone, and globular patterns. After dermabrasion, nearly half of the lesions (46%) became dermatoscopically asymmetric. Among all lesions, structureless areas, dotted vessels and erythema were the most frequent new dermoscopic structures.

CONCLUSION

Trauma after dermabrasion may induce significant dermoscopic changes in melanocytic nevi. Although the global pattern did not change, most of the lesions became asymmetric, with the appearance or fading of dermoscopic structures and colors. A history of recent trauma should be investigated when evaluating pigmented lesions.

[Breast lesions of a metastatic melanoma on a radiotherapy territory: Treatment by vemurafenib and carcinologic surgery]

INTRODUCTION

This article describes the unique case of a female patient who presented distant melanoma metastasis on the breast while having irradiation therapy for breast cancer. This happened eight months after the initial treatment for a melanoma of the back (under the right scapula). Furthermore, this case report demonstrates the efficiency of Vemurafenib® as a treatment for late stage melanomas.

CASE REPORT

The patient was a 47-year-old female that had a superficial spreading melanoma under the right scapula (Breslow 1.02mm) that was treated with 2cm skin excision and sentinel lymph node sampling that was negative. The melanoma was positive for the BRAF600E mutation. One month after this incident, the patient developed breast cancer that was treated with conservative surgery and radiotherapy. Three months after the end of the irradiation treatment, she developed multiple melanoma metastasis on the skin of the breast. Our multidisciplinary team decided to initiate a treatment with vemurafenib. The patient showed an excellent response, so the surgical team completed the treatment with a radical mastectomy and immediate reconstruction with a pedicled latissimus dorsi flap. The histologic report of the mastectomy specimen showed no sign of melanocytic proliferation, that demonstrates the efficacy of vemurafenib. The patient showed no relapse after two years of follow-up.

DISCUSSION

The speed of development and location of cutaneous metastases in this case brought us to think about the effects of radiation therapy on the skin. Radiation therapy causes acute complications (radiodermatitis) by cellular and molecular mechanisms. Moreover, depressed immunity is found after irradiation. Association of these mecanisms could explain the appearance of these metastases in irradiation field. The efficiency of vemurafenib found in our case is consistent with what is described in literature, especially with the improvement in median overall survival.

CONCLUSION

This case demonstrates a unique case of distant melanoma metastasis on the irradiation field of a breast cancer. It also demonstrates the efficacy of vemurafenib as well as the efficacy of a radical complementary surgical treatment in these patients.

The recurrent nevus phenomenon: a history of challenge, controversy, and discovery

CONTEXT

The diagnosis of recurrent nevus poses a potential challenge to practicing pathologists. Although most recurrent nevi show uniform microscopic findings and pose no great diagnostic difficulty, a few cases exhibit some histopathologic features similar to, and in some cases indistinguishable from, melanoma. Historically, the term pseudomelanoma has been used in the literature to describe such recurrent nevi, although this label has the potential for confusion and is no longer the favored term for recurrent pigmented melanocytic nevi.

OBJECTIVE

To describe historical, histopathologic, and immunohistochemical features of recurrent pigmented melanocytic nevi and to review briefly the literature surrounding the mechanism of recurrence.

DATA SOURCES

Published peer-reviewed literature and the authors' personal experience.

CONCLUSIONS

Recognition of the histopathologic pattern of recurrent nevi leads the pathologist to the correct diagnosis in most cases; however, in particularly challenging specimens or in circumstances in which there is insufficient clinical history, immunohistochemical studies have proved helpful in distinguishing recurrent nevi from melanoma.