Lipomatous melanocytic nevomatosis

Oral melanocytic nevi: a clinicopathologic study of 100 cases

OBJECTIVE

The purpose of this study was to evaluate the clinical and histopathologic features of oral melanocytic nevi (OMN).

STUDY DESIGN

One hundred cases of OMN were retrieved from the files of two oral pathology services, and the data were analyzed with regard to histologic type and clinical features.

RESULTS

Intramucosal nevus was the most common type (61%), followed by common blue nevus (23%), compound nevus (7%), and junctional nevus (3%). Combined nevus and cellular blue nevus were rare (2% each). The hard palate was the most commonly affected site (33%), followed by the buccal mucosa (18%), vermilion border of the lip (18%), and gingiva (15%). An interesting case of intramucosal nevus with lipomatosus-like changes and neurotization and two cases of oral dysplastic nevus are also reported.

CONCLUSIONS

Intramucosal and common blue nevi are the most common types of OMN. Dysplastic nevus, which is recognized as a marker for melanoma in the skin, can rarely involve the oral cavity. Accordingly, dentists, especially oral and maxillofacial pathologists, should become familiar with the clinical and histopathologic features of this entity.

Update on melanocytic nevi in children

A new or changing melanocytic nevus in a child or adolescent often leads to concern in parents and physicians. To avoid undue alarm and unnecessary procedures, dermatologists should be aware of the natural history and clinical spectrum of nevi in pediatric patients, as well as findings that are potentially worrisome in this age group. This review provides an update on melanocytic nevi in children, focusing on their dynamic evolution over time, molecular insights into nevogenesis, and phenotypic markers for increased risk of melanoma in adolescence and adulthood. Special considerations for Spitz nevi and nevi located in particular sites (eg, scalp, acral, genital) are highlighted. Current understanding of the risks associated with congenital melanocytic nevi of different sizes and strategies for the management of children with numerous acquired nevi, Spitz nevi, and congenital nevi are also discussed.

Lipomatous congenital melanocytic nevus presenting as a neck mass in a young adult

Congenital melanocytic nevus (CMN) is a melanocytic proliferation that has its onset at birth or shortly thereafter and shows characteristic histopathologic features including symmetric proliferation of benign melanocytes, extension of nevus cells into the deep reticular dermis and subcutis, maturation of melanocytes with descent, tracking of melanocytes around and within adnexal structures, vessels, or nerves and splaying of collagen bundles by nevus cells arranged in single rows or cords. We report the case of a 34 year old previously healthy woman who presented with a progressively enlarging soft tissue mass in the right neck and back adjacent to a medium sized CMN. Magnetic resonance imaging showed multiple lipomatous masses within the soft tissues of the posterior superficial neck. Subsequent excision of the soft tissue mass showed a well circumscribed lipomatous lesion with diffuse infiltration by benign appearing melanocytes within the fat lobules. Excision of the mass was not accompanied by overlying skin and, thus, posed a diagnostic challenge. Sudden increase in the size of a CMN is worrisome for the development of a melanoma, however, this lesion lacked significant cytologic atypia and mitotic figures, and had a low proliferative index by Ki-67 immunohistochemistry. This case serves to illustrate the initial diagnostic dilemma as well as the plasticity of the neural crest cells.