title: Metastatic small cell carcinoma to the thyroid gland: a pathologic and molecular study demonstrating the origin in the urinary bladder.
abstract: Small cell carcinomas may occur in the thyroid gland. Infrequently, they are primary tumors, and have been interpreted as variants of medullary thyroid carcinoma. However, the vast majority of small cell carcinomas involving the thyroid gland are metastatic tumors. In some cases, demonstration of the primary tumor is not easy. An example of a small cell carcinoma metastatic to the thyroid is presented in this report. The primary tumor was a small cell carcinoma that occurred as a minor component in a transitional carcinoma of the urinary bladder. The microscopical and immunohistochemical features of both tumors, in the thyroid and the bladder, were identical. Moreover, both tumors exhibited an identical mutation in p53, as well as similar loss of heterozygosity at 10q23 and RASSF1A promoter hypermethylation, clearly indicating that the bladder tumor was the site for the primary tumor of the patient.
authors.affiliation: Department of Pathology, Hospital Universitari Arnau de Vilanova, University of Lleida, IRBLLEIDA, Alcalde Rovira Roure 80, 25198 Lleida, Spain.
authors.forename: Soraya
authors.initials: S
authors.lastname: Puente
authors.forename: Ana
authors.initials: A
authors.lastname: Velasco
authors.forename: Pilar
authors.initials: P
authors.lastname: Gallel
authors.forename: Judit
authors.initials: J
authors.lastname: Pallares
authors.forename: Luis
authors.initials: L
authors.lastname: Perez-Ruiz
authors.forename: Susana
authors.initials: S
authors.lastname: Ros
authors.forename: Javier
authors.initials: J
authors.lastname: Maravall
authors.forename: Xavier
authors.initials: X
authors.lastname: Matias-Guiu
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D001483:Base Sequence; D018288:Carcinoma, Small Cell / Q000235:genetics* / Q000378:metabolism / Q000556:secondary*; D002295:Carcinoma, Transitional Cell / Q000473:pathology; D019175:DNA Methylation; D004252:DNA Mutational Analysis; D006801:Humans; D007150:Immunohistochemistry; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011471:Prostatic Neoplasms / Q000473:pathology; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000556:secondary*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000235:genetics; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology*
chemical_list: C411762:RASSF1 protein, human; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins