The intended and incidental

Abstract

Background

Melanoma is a malignancy originating from melanocytes, with the potential to affect not only the skin but also any melanocyte-containing tissue, including mucosal surfaces. Mucosal melanoma (MM), although less common than its cutaneous counterpart, is characterized by a more aggressive course and poorer prognosis. In the head and neck region, MM primarily involves the nasal and sinonasal cavities, with the oral cavity being less frequently affected, particularly at the hard palatal mucosa and maxillary gingiva. Distinct from cutaneous melanoma, which has a well-established link to ultraviolet exposure, MM lacks definitive risk factors. This gap in understanding poses a significant challenge in early detection and prevention strategies. The prognosis remains dire, as evidenced by a 5-year overall survival rate ranging from 0 to 45%, largely due to late-stage diagnosis.

Case Summary

A 65-year-old female patient with a history of hypertension, eczema, and hyperlipidemia was notified by her general dentist during routine dental prophylaxis of a pigmented macule on the left hard palatal mucosa. Routine surveillance was recommended. Three months later, she noted an asymptomatic blister-like swelling in the same area as what she believed to be the unchanged macule. Two months later, the patient presented to the oral medicine clinic. Intra-oral examination revealed a 2.0- × 1.3- × 0.4-cm ulcerated brown sessile mass, concerning for neoplasia. An incisional biopsy revealed mucosal melanoma. Comprehensive imaging work-up, including positron emission tomography and computed tomography, revealed an incidental fluorodeoxyglucose-avid lung nodule. Biopsy of the nodule revealed primary lung adenocarcinoma. Treatment will include left hemi-maxillectomy for the MM, followed by evaluation by thoracic surgery and radiation oncology for treatment of the lung adenocarcinoma.

Conclusions

MM is a rare, aggressive malignancy with a poor prognosis that can affect the oral cavity. Oral health providers should routinely screen for suspicious pigmented lesions to facilitate early diagnosis and treatment. Additionally, it has been reported that patients with MM are more likely to have a second primary malignancy compared with those with other types of melanoma. Herein, we present such a case of primary oral MM and primary lung adenocarcinoma that was diagnosed incidentally during the MM workup process.