title: Combined papillary and mucoepidermoid carcinoma of the thyroid gland: a possible collision tumor diagnosed on fine-needle cytology. Report of a case with immunocytochemical and molecular correlations.
abstract: Fine-needle cytology (FNC) is frequently used to diagnose thyroid nodules discovered by palpation or imaging studies. Molecular tests on FNC material may increase its diagnostic accuracy. We report a case of a classic papillary thyroid carcinoma combined with a mucoepidermoid carcinoma correctly identified on FNC. The papillary component had a classic immunophenotype (CK19+, TTF1+), while the mucoepidermoid one was only focally CK19+. Point mutations (BRAF and RAS) and rearrangements (RET/PTC) of the papillary component have been also investigated on FNC samples, with resulting concurrent rearrangements of RET/PTC1 and RET/PTC3, but no point mutations. The histogenesis of combined papillary and mucoepidermoid carcinoma of the thyroid still remains partly unsettled, and further genomic studies are needed to shed some more light on this peculiar neoplasm.
authors.affiliation: Istituto Cantonale di Patologia, Sevizio di Citologia Clinica, via Alberto Franzoni 45, 6601, Locarno, Switzerland.
authors.forename: Franco
authors.initials: F
authors.lastname: Fulciniti
authors.forename: Emilia
authors.initials: E
authors.lastname: Vuttariello
authors.forename: Celeste
authors.initials: C
authors.lastname: Calise
authors.forename: Mario
authors.initials: M
authors.lastname: Monaco
authors.forename: Luciano
authors.initials: L
authors.lastname: Pezzullo
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Chiofalo
authors.forename: Francesca
authors.initials: F
authors.lastname: Di Gennaro
authors.forename: Maria Gabriella
authors.initials: MG
authors.lastname: Malzone
authors.forename: Anna Cipolletta
authors.initials: AC
authors.lastname: Campanile
authors.forename: Nunzia Simona
authors.initials: NS
authors.lastname: Losito
authors.forename: Gerardo
authors.initials: G
authors.lastname: Botti
authors.forename: Gennaro
authors.initials: G
authors.lastname: Chiappetta
mesh_terms: D000328:Adult; D044963:Biopsy, Fine-Needle; D002277:Carcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D018277:Carcinoma, Mucoepidermoid / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D002291:Carcinoma, Papillary; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018198:Mixed Tumor, Malignant / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D025202:Molecular Diagnostic Techniques; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology