title: Melanin-producing medullary thyroid carcinoma with glandular differentiation.
abstract: 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.
authors.affiliation: Department of Pathology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Ishioka
authors.forename: Y
authors.initials: Y
authors.lastname: Miura
authors.forename: N
authors.initials: N
authors.lastname: Sasano
authors.forename: K
authors.initials: K
authors.lastname: Takaya
authors.forename: T
authors.initials: T
authors.lastname: Mouri
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: Y
authors.initials: Y
authors.lastname: Nakazato
authors.forename: R
authors.initials: R
authors.lastname: Yamada
mesh_terms: 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
chemical_list: D008543:Melanins