Amelanotic Melanocytic Nevus of the Oral Cavity: A Case Report and Literature Review.

Abstract

Amelanotic melanocytic nevi of the oral cavity are uncommon lesions that often present a diagnostic challenge for clinicians, primarily due to their nonspecific clinical appearance and the broad spectrum of possible differential diagnoses. These lesions can mimic a variety of benign and malignant conditions, requiring precise histopathological confirmation. The primary objective of this article is to present a comprehensive case report-tracing the course from initial presentation through diagnostic workup to final diagnosis-and to provide an overview of the current literature on oral amelanotic melanocytic nevi. We report the case of a 27-year-old female who presented with a small, exophytic mass located in the anterior mandibular gingival region. The lesion was asymptomatic and lacked pigmentation, adding to the diagnostic uncertainty. A range of differential diagnoses was considered, including pyogenic granuloma, peripheral ossifying fibroma, and squamous cell carcinoma. Due to the lesion's limited size and accessibility, an excisional biopsy was performed under local anesthesia. Histopathological examination revealed an amelanotic melanocytic nevus, a rare variant characterized by the absence of melanin pigment, further complicating the clinical impression. The diagnosis was confirmed through immunohistochemical staining, which demonstrated melanocytic markers consistent with a nevus. The patient was followed up with for six months postoperatively, with no evidence of recurrence or malignant transformation. This case highlights the critical role of biopsy in achieving a definitive diagnosis, especially in lesions with atypical clinical presentations. It also underscores the importance of considering amelanotic melanocytic nevi in the differential diagnosis of nonpigmented oral lesions, as well as maintaining vigilance regarding the rare possibility of amelanotic melanoma.