Metastatic choroidal melanoma to a follicular adenoma of the thyroid: A case of tumour-to-tumour metastasis

Abstract

Thyroid metastasis from uveal melanoma is a rare occurrence. We report the case of a 56-year-old woman who was diagnosed with choroidal melanoma, and treated with photodynamic therapy and plaque brachytherapy. An incidental right thyroid lesion was detected during her initial diagnostic workup, for which she subsequently underwent a hemithyroidectomy. Histological examination showed a follicular adenoma containing multiple foci of metastatic choroidal melanoma, representing a unique case of tumour-to-tumour metastasis from a choroidal melanoma to a follicular adenoma of the thyroid. This case highlights the importance of considering metastatic disease as a differential for thyroid lesions arising in patients with a history of malignancy.