Melanin-producing medullary thyroid carcinoma with glandular differentiation.
A rare case is reported of melanin-producing medullary thyroid carcinoma in a 62-year-old man. Intraoperative imprints of the thyroid tumor revealed numerous detached tumor cells containing large amounts of brown pigment. The Fontana-Masson argentaffin reaction with bleach confirmed that those granules were melanin. Histologically, the tumor was composed of two different components--a medullary area with hyalinized stroma and a follicular area. Melanin was scattered in both areas. The tumor cells in both areas were immunoreactive to carcinoembryonic antigen, calcitonin, gastrin-releasing peptide, somatostatin, met.-enkephalin, neuron-specific enolase, chromogranin and neurofilaments, and negative for thyroglobulin and S-100 protein. The histologic diagnosis was melanin-producing medullary thyroid carcinoma with glandular differentiation. Although various kinds of peptides and amines have been reported to be produced in medullary thyroid carcinoma, melanin production is quite rare; this appears to be only the third reported case.
Kimura
N
N
Department of Pathology, Tohoku University School of Medicine, Sendai, Japan.
Ishioka
K
K
Miura
Y
Y
Sasano
N
N
Takaya
K
K
Mouri
T
T
Kimura
T
T
Nakazato
Y
Y
Yamada
R
R
D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008543:Melanins / Q000096:biosynthesis*; D008875:Middle Aged; D013961:Thyroid Gland / Q000473:pathology; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology
D008543:Melanins