Oral malignant melanoma of the tongue with suspected intralingual in-transit metastasis.

Oral malignant melanoma (OMM) is a rare and aggressive malignancy, and involvement of the tongue is particularly uncommon. We report a case presenting with two isolated pigmented tongue lesions clinically resembling benign conditions. Excisional biopsy of the anterior lesion confirmed melanoma, and the tongue base lesion was clinically suspected to represent possible in-transit metastasis. To our knowledge, in-transit metastasis in OMM is not well documented. The patient underwent wide local excision followed by adjuvant pembrolizumab based on cutaneous melanoma guidelines. Final pathological staging was pT3b pN1c cM0 (stage IIIC). At 1-year follow-up, no recurrence or metastasis was observed and oral function was preserved with a palatal augmentation prosthesis. This case highlights diagnostic challenges and the importance of early biopsy and multidisciplinary management. Additional cases and further multicentre studies are needed to validate these observations and guide the development of standardised treatment protocols in the diagnosis and management of OMM.