Blue Nevus of The Palate: A Case Image

Abstract

A 54-year-old female patient was referred to the oral surgery department of a public university with a complaint of a dark spot on the palate that had been present for eight months. Clinical examination revealed a well-circumscribed, darkly pigmented macule measuring approximately 1.5 cm × 1 cm located in the posterior hard palate. The lesion’s location and size raised suspicion of malignancy. An incisional biopsy was performed, and histopathological analysis showed the presence of spindle cells containing light brown pigmented granules compatible with melanin. The final diagnosis was of blue nevus. The lesion was surgically excised, with satisfactory healing, and a follow-up period of 5 months. Blue nevus is a melanocytic lesion that typically presents as a small pigmented spot and is rare in the oral cavity. This case is notable due to the lesion’s size and location and overlapping features commonly associated with malignancy, posing a diagnostic challenge, particularly for pathologists who infrequently review melanocytic lesions. This highlights the critical role of histopathological analysis in establishing a definitive diagnosis. Additionally, careful clinical follow-up is essential to monitor healing and detect any potential recurrence.

A 54-year-old female patient was referred to the Oral and Maxillofacial Surgery Division at the School of Dentistry, Federal University of Juiz de Fora (Juiz de Fora, MG, Brazil), concerned about the appearance of a dark ovoid macule on the palate that had developed over the past 8 months. Clinical examination affirmed this clinically asymptomatic, 1.5 × 1.0 cm, darkly yet homogeneously pigmented macule with well-defined borders, located on the posterior hard palate (Fig. 1). There was no palpable cervical lymphadenopathy, and no additional pigmented lesions were observed on the skin or other mucosal sites. Diascopy was performed to rule out the possibility of a vascular malformation. Given the negative result and the absence of systemic involvement, the differential diagnoses included acquired melanocytic nevi, oral melanoma, melanocytic macule, and melanoacanthoma.

Fig. 1.

Intraoral clinical aspect, showing a well-defined black macule, measuring 1.5 cm in greatest dimension, located in the left posterior hard palate

An incisional biopsy was performed (Fig. 2). Histopathological analysis revealed a fragment of mucosa covered by keratinized stratified squamous epithelium. In the underlying connective tissue, there was a spindle cell proliferation predominantly aligned parallel to the epithelial surface. These cells contained light brown pigmented granules consistent with melanin and extended from the lamina propria into deeper layers. The histopathological diagnosis was consistent with a common blue nevus.

Fig. 2.

(A) Intraoral view showing the demarcated area for incisional biopsy. (B) Specimen obtained from the incisional biopsy. (C) Immediate postoperative appearance after the procedure

Surgical excision was performed, followed by the installation of a provisional palatal obturator prosthesis to assist in the retention of the surgical cement and to promote wound isolation and healing (Fig. 3). The decision for surgical removal was made based on the patient’s aesthetic concern, as well as on the management approaches commonly recommended in the literature [1–3]. The histopathological report of the surgical excision confirmed the diagnosis of blue nevus with negative surgical margins (Fig. 4). At present, the patient has a postoperative follow-up of 5 months, with complete wound healing and no evidence of lesion recurrence (Fig. 5).

Fig. 3.

(A) Specimen removed after surgical excision of the lesion. (B) Immediate postoperative period. (C) Temporary palatal obturator prosthesis in position

Fig. 4.

(A) Low-power view showing keratinized stratified squamous epithelium overlying connective tissue with an extensive proliferation of pigmented spindle-shaped cells containing melanin granules. The pigmented area extends from the lamina propria into deeper connective tissue, where minor salivary glands and adipose tissue are present (H&E, 25×). (B) Intermediate magnification highlighting pigmented cell proliferation immediately beneath the epithelium and extending into the underlying stroma (H&E, 100×). (C) High-power view revealing numerous spindle cells laden with coarse brown melanin granules interspersed among collagen fibers (H&E, 400×)

Fig. 5.

Intraoral postoperative clinical aspect after 5 months, demonstrating complete resolution and absence of recurrence

Acquired melanocytic nevi are common on the skin but are rare in the oral cavity, where they primarily affect the palate and gingiva. Based on their histopathological features, oral melanocytic nevi can be classified as junctional, compound, intramucosal, blue, or Spitz nevi [4]. Blue nevus, also referred to as a Jadassohn–Tièche nevus, is characterized by the presence of spindle-shaped melanocytic cells located deep within the connective tissue. Although it is the second most common type of oral melanocytic nevus, blue nevus accounted for only 3.8% of the cases in a retrospective Brazilian study analyzing 761 pigmented oral lesions [5]. It typically presents as a solitary macule or papule, with a smooth surface, well-defined borders, and a diameter of less than 10 mm, most commonly located on the hard palate [3]. Its dark blue color is generally attributed to the Tyndall effect [1].

Clinical presentations of blue nevus can vary considerably, with some cases presenting as diffuse areas with irregular margins [2]. Considering that oral melanocytic nevi are clinically indistinguishable from early-stage melanomas, the recommended approach involves biopsy, followed by conservative excision, and long-term follow-up [1]. In this context, the present case of a blue nevus on the hard palate underscores the critical importance of a comprehensive diagnostic approach. This should encompass a detailed patient history, meticulous clinical examination, and histopathological analysis to ensure accurate diagnosis and appropriate management.

Author Contributions

All authors contributed to the study conception and design. Material preparation and data collection were performed by LSSR, IAF and MFC. Analysis was performed by YLM, DAAM, VPW and MFC. The first draft of the manuscript was written by LSSR, IAF and YLM and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Funding

This study was not supported by any funding.

Data Availability

No datasets were generated or analysed during the current study.

Declarations

Ethics Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Consent To Participate

Informed consent was obtained from all individual participants included in the study.

Consent for Publication

Consent for publication was obtained for every individual person’s data included in the study.

Competing Interests

The authors declare no competing interests.