Melanin production in medullary thyroid carcinoma |
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Authors: | K. BEN ROMDHANE R. KHATTECH M. BEN OTHMAN A. GAMOUDI A. AMMAR M. CAMMOUN |
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Affiliation: | Department of Pathology, Institut Salah Azaiez, Bab Saadoun, Tunis, Tunisia |
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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 differenciation remains an exceptional phenomenon. |
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Keywords: | thyroid medullary carcinoma melanin C-cell |
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