Background:
Malignant melanoma (MM) is the third most common cutaneous malignancy and is associated with high rates of mortality. 40% to 60% of patients diagnosed with MM have a mutation in codon 600 of BRAF, the presence of which will influence management and prognosis. BRAF V600K variant account for 5-30% of such mutations and the head and neck is the most common site for primary tumour location. It is associated with increasing age, male sex, chronic sun exposure and higher rates of metastases compared the more common BRAF V600E variant.
Case:
A 76 year old male was referred to the Oral & Maxillofacial department with a one year history of an increasing, fungating cutaneous mass overlying the right parotid with associated pain and hearing impairment. The tumour measured 10X7cm at initial presentation. Incisional biopsy confirmed subcutaneous deposits of metastatic melanoma and molecular genetic analysis was positive for BRAF V600K. CT-TAP and MRI brain excluded distant metastases. Treatment involved a course of radiotherapy followed by four cycles of immunotherapy with nivolumab/ipilimumab, where a significant reduction in tumour size and absence of disease progression on follow-up imaging was evident.
Conclusion:
Although rare, BRAF V600K variant of MM is most commonly found in the head and neck. Early detection and multidisciplinary involvement is critical for successful treatment.