Malignant blue nevus of the parotid gland: A case report

Blue Nevus of the Hard Palate: The Importance of a Careful Examination in an Emergency Setting

Oral common blue nevus is an asymptomatic, benign, rare, pigmented lesion and sometimes clinically indistinguishable from other pigmented lesions such as the cellular blue nevus or early-stage malignant melanoma. Since it shows clinical similarities with a malignant lesion and with cellular blue nevus that can itself suffer malignant transformation, the decisive diagnosis is crucial for adequate treatment, follow-up, and prognosis. Diagnosis confirmation is given by histological analysis, the reason why most oral pigmented lesions are excised. The following case presents an asymptomatic oral pigmented lesion of the hard palate discovered during observation in an emergency setting due to an abscess of dental origin. The lesion was fully excised, and histological examination reported a “common blue nevus.” In this case, we intend to present a rare lesion of the oral cavity and the importance of performing a routine oral examination when given a chance as a preventive approach.

Cellular blue nevus tumor presenting as a submandibular lymph node in a 16-year-old

The cellular blue nevus tumor is a type of dendritic melanocytic nevus that is typically benign and exceedingly rare. The incidence of all blue nevi is about 1%, usually affecting the adult population and appearing on the extremities, sacrococcygeal or gluteal regions. There have only been a handful of case reports cited in the literature where cellular blue nevi present in the head and neck region, usually affecting the scalp and young adult population (7, 8). As such, it is exceedingly rare to encounter a cellular blue nevus tumor in the neck or infiltrating into neck lymph nodes. Here we report a rare case of a cellular blue nevus tumor presenting as a right neck mass in a pediatric 16-year-old patient, shown to invade into the submandibular lymph node and surrounding soft tissue. It is important to be aware of the cellular blue nevus tumor as a differential diagnosis in pediatric neck masses. Histological evaluation is necessary to determine tumor aggression and malignant potential which can guide further treatment in pediatric patients.

Blue nevi and related lesions: a review highlighting atypical and newly described variants, distinguishing features and diagnostic pitfalls

Blue nevi and related entities are a heterogenous group of congenital and acquired melanocytic tumors that includes established entities such as dendritic ("common") blue nevus and cellular blue nevus, and their numerous clinical and pathologic variants, such as deep penetrating nevus. They share several clinical and morphologic features including their blue tinctorial properties, the presence of a dermal proliferation of spindle, fusiform or ovoid cells, associated melanin pigment (both within the melanocytic tumor cells and also within macrophages) and stromal sclerosis and, at least focal positivity for HMB-45 (Gp100). Some variants, such as deep penetrating nevus, often show considerable variation in nuclear size and shape, and, as a consequence, are at risk of being misdiagnosed as melanoma by those unfamiliar with their characteristic morphologic features. The so-called malignant blue nevus is a controversial term denoting melanomas arising in association with or exhibiting some morphologic similarities to blue nevus. There are also lesions that are probably related to blue nevi, such as the recently described pigmented epithelioid melanocytoma and the neurocristic hamartomas, whose nature, biologic behavior, and relationship to the better established entities remains to be clearly established. This review aims to present a brief overview of these lesions, highlighting their pathologic characteristics, distinguishing features and potential diagnostic pitfalls, with particular emphasis on recently described entities, molecular findings, controversial areas, and approaches to diagnosis.