Abstract

Background: Melanoma is a relatively uncommon malignant neoplasm, either primary or secondary. We present a case of delayed metastatic melanoma to the pharyngeal tonsil.

Case report: A 70-year-old Chinese male presented for half a year due to vague speech and snoring and then found tonsil enlargement. Three years prior to presentation, he had undergone primary resection and systemic therapy for cutaneous melanoma on the sole of his foot. Tonsil biopsy confirmed the diagnosis of metastatic melanoma. Currently the patient is undergoing chemotherapy.

Conclusion: Metastatic melanoma is a rare disease, and metastatic lesions may occur at any location. For the long-term survival of patients, careful examination should be done during the follow-up period, including head and neck.

Keywords: metastatic melanoma; tonsillar neoplasms.

Citation: Zhou Y, Huang ZC, Wang Y. Delayed metastatic melanoma to the pharyngeal tonsil in a Chinese male. J Clin Images Med Case Rep. 2022; 3(1): 1554.

Introduction

Melanoma is a relatively uncommon malignant neoplasm, either primary or secondary. Malignant melanoma is a highly unpredictable tumor that has capacity to metastasize to any organ [1]. Melanoma deaths accounted for 70%-75% of deaths from skin cancer and 1.7% of all cancer deaths [2]. The high mortality rate associated with melanoma is attributed primarily to its high local and distant metastatic rate. Distant metastasis is most commonly found in the lungs, liver and brain, but metastatic melanoma has been found in uncommon places, such as tonsil. Dozens of cases of malignant melanoma of tonsil have been reported. We report a rare case of tonsillar metastasis three years after melanoma.

Case report

A 70-year-old Chinese male presented to the otolaryngology clinic for half a year of vague speech and snoring and then found tonsil enlargement. Three years prior, he had undergone an excision of a cutaneous melanoma on the sole of his foot. A bluish black tissue like tumor was seen in the right tonsil fossa, about 3 X 4 X 5 cm in size, reaching the level of nasopharynx, close to the midline inside and near the root of epiglottis below. It was brittle and easy to bleed when touched (Figure 1). The patients were treated with chemotherapy after operation. In 2019, brain metastasis and lung metastasis were found in the reexamination, and the chemotherapy regimen was changed to continue the treatment. Considering the improvement of local symptoms and quality of life, the right tonsillectomy was performed. After the operation, the symptoms were relieved. The pathologic diagnosis was typical tonsillar metastasis of a malignant melanoma (Figure 2). Currently the patient is undergoing chemotherapy and follow-up.

Discussion

The majority of melanomas are cutaneous, and <10% are of mucosal origin of the aerodigestive tract. Due to the indolent and painless nature of the primary melanoma tumor, many patients present with distant metastasis. The median survival at this stage is 6-9 months, and the 5-year survival rate is <5% [3]. Patients with multiple metastases often have poor prognosis and died of systemic disseminated diseases. More than 60% of the reported mucosal metastases have been noted within 24 months after diagnosis of the primary tumor [4]. However, metastasis to the palatine tonsil was noted in our patients over 24 months of their initial presentation. The tonsil is a component of Waldeyer’s ring that provides a primary rudimentary defense against foreign pathogens. The tonsillar capsule is penetrated with a complex venous and lymphatic network. Hence, metastasis to the palatine tonsil is considered hematogenous or lymphatical and is likely widespread to other visceral structures at the time of the tonsillar manifestation.

This type of metastasis is extremely rare, comprising only 0.8% of all tonsillar malignancies [5]. There is no unified standard for the treatment of metastatic tonsillar malignant melanoma. Some foreign literatures have pointed out that considering the radical effect of surgery and the postoperative survival rate of patients, it is suggested that tonsillectomy be performed to control the local symptoms of patients when conditions permit [6]. And immune intervention may help to prolong the life cycle [7]. Metastatic melanoma is a rare disease, and metastatic lesions may occur at any location. For the long-term survival of patients, a comprehensive examination including thorough oropharyngeal inspection is strongly recommended at every visit.

References

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