title: Cytological findings of intrathyroidal epithelial thymoma/carcinoma showing thymus-like differentiation: a study of eight cases.
abstract: The purpose of this article is to describe the cytologic findings of intrathyroidal epithelial thymoma/carcinoma showing thymus-like differentiation (ITET/CASTLE) in detail and discuss its differential diagnoses. We examined cytologic specimens taken from eight ITET/CASTLE cases, who underwent fine needle aspiration. Cytologic features of ITET/CASTLE include (1) hypercellularity, (2) large cell clusters without papillary or follicular pattern, (3) round or spindle tumor cells with distinct nucleoli and cell border, (4) few keratinized cells and intracytoplasmic lumina (ICL), and (5) lymphocytic background. The differential diagnoses included poorly differentiated carcinoma, metastatic lymphoepithelioma, squamous cell carcinoma, and mucoepidermoid carcinoma. The presence of individual keratinizing cells and ICL and the location of the tumor may be helpful in indicating ITET/CASTLE.
authors.affiliation: Department of Diagnostic Pathology, Kuma Hospital, Kobe, Japan. mhirokawa@kumah.or.jp
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Hirokawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Kuma
authors.forename: Akira
authors.initials: A
authors.lastname: Miyauchi
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D018277:Carcinoma, Mucoepidermoid / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D015726:Giant Cells / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000378:metabolism; D013945:Thymoma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D013953:Thymus Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors