Human melanoma cells express functional receptors for thyroid-stimulating hormone.

We have reported a high prevalence of hypothyroidism in the cutaneous melanoma population, suggesting that the pathologic hormonal environment of hypothyroidism promotes melanoma growth. The objective of this study was to test the hypothesis that TSH, which circulates at elevated levels in hypothyroid individuals, stimulates the growth of melanoma cells. Our results show that TSH receptors (TSHR) are expressed by virtually all cutaneous melanocytic lesions, including benign nevi, dysplastic nevi, and melanomas, with higher expression found in malignant and pre-malignant lesions.