Clinically Unusual Pigmented Lesion of the Buccal Mucosa: A Case Report

We present a rare clinical case of a 64-year-old patient with a pigmented lesion localized in the left buccal mucosa. Subjective complaints of slight pain and discomfort in the process of eating and increased sensitivity when consuming hot food were reported. According to the information provided by the patient, the lesion had progressively increased in size. A history of previous dental manipulations was reported, namely, the extraction of teeth with amalgam obturations in the left half of the maxilla as per relevant indications. During the intraoral examination, a flat, black-colored lesion, 0.4 cm in diameter, with well-defined borders was observed in the buccal mucosa. Teeth 25, 26, and 27 were previously extracted five to seven years ago. An orthopantomography was performed as a routine procedure. It did not show any presence of X-ray contrast areas that could explain the symptoms of the patient. The symptomatic nature of the lesion as well as the negative radiological findings prompted surgical treatment and excisional biopsy with subsequent histological evaluation to rule out oral malignancy. An excision was performed. During the follow-up examination in the next eight days, all the symptoms of the patient were gone. The conclusion of the pathology report was "histological findings and clinical data consistent with amalgam tattoo". The amalgam tattoo is the most frequent iatrogenic pigmented lesion of the oral mucosa, which results from the implantation of amalgam particles in the soft tissues and it is usually asymptomatic. In this case, no surgical treatment is needed. However, in some rare cases, like the one we are presenting, some symptoms can occur and complicate the diagnostic process. In these cases, the complete excision of the lesion is to be performed with subsequent histological evaluation. The atraumatic intervention of teeth, obturated with definitive amalgam fillings, is a main factor for preventing this kind of pigmentation of the oral mucosa.