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Updated: Sep 11, 2026

An Orthotopic Mouse Model of Anaplastic Thyroid Carcinoma
Published on: April 17, 2013
Melanin production in medullary thyroid carcinoma
K Ben Romdhane1, R Khattech, M Ben Othman
1Department of Pathology, Institut Salah Azaiez, Tunis, Tunisia.
Abstract:
A case of melanin-producing medullary thyroid carcinoma is reported in a 51-year-old man. Histologically, the tumour had a typical pattern of medullary thyroid carcinoma with numerous scattered pigmented cells which contained large amounts of melanin pigment as confirmed by bleached Fontana-Masson stain. Immunohistochemical staining revealed positivity of almost all tumour cells for calcitonin and chromogranin, whereas S-100 protein and HMB-45 staining was positive only in the pigmented tumour cells. This finding confirms the ability of medullary thyroid carcinoma cells to have multidirectional differentiation, although melanocytic differentiation remains an exceptional phenomenon.
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