title: Relevance of immunocytochemistry on thin-layer cytology in thyroid lesions suspicious for medullary carcinoma: a case-control study.
abstract: BACKGROUND
  Fine needle aspiration cytology represents the most important tool in the diagnosis of thyroid nodules, mostly in discriminating malignant from benign lesions. The diagnosis of medullary thyroid carcinoma (MTC) may present some problems related to its deceptive morphologic picture. This diagnosis may be supported by immunocytochemistry (ICC), which may be difficult to carry out on the conventional smears.
  
  
  METHODS
  The diagnostic efficacy of ICC for the diagnosis of MTC with respect to other thyroid neoplasms on slides processed by thin-layer cytology (TLC) is evaluated.
  
  
  METHODS
  In the period between January 2002 and December 2005, 8,200 FNAB were processed. ICC on TLC slides was required in 33 cases. Conventional smears were fixed in ethanol, whereas TLC slides were processed with the Thin Prep 2000 method. All slides were then stained with Papanicolaou. In all cases where MTC was morphologically suspected, ICC for calcitonin, monoclonal carcinoembryonic antigen, and thyroglobulin was carried out only on TLC slides.
  
  
  RESULTS
  Thirty-three thyroid cytologic cases had ICC on the TLC slides, including 22 follicular proliferations and 11 malignant lesions. The application of ICC on TLC was conclusive in 32 cases and inconclusive in 1 case. Twenty cases underwent surgery. No false-positive and false-negative cases were found. Sensitivity and specificity were 100%, and the overall diagnostic accuracy was 100%.
  
  
  CONCLUSIONS
  ICC can be successfully applied on TLC slides. The combined results of morphology and a small immunopanel including thyroglobulin, calcitonin, and carcinoembryonic antigen yields a 100% diagnostic efficacy for MTC.
  
  
  CONCLUSIONS
  Fine needle aspiration cytology is an excellent technique for diagnosing malignant neoplasms of the thyroid, especially those derived from the follicular cells. A correct preoperative diagnosis of C-cell-derived tumors (MTC), which is essential for both the surgical approach to the primary tumor and the management of the patient, should rely not only on the morphologic picture but also on the immunocytochemical yielding using an immunopanel, which is particularly satisfactory on the TLC slides.
authors.affiliation: Endocrinology, Catholic University of Sacred Heart, Largo Francesco Vito, Rome, Italy.
authors.forename: Esther Diana
authors.initials: ED
authors.lastname: Rossi
authors.forename: Marco
authors.initials: M
authors.lastname: Raffaelli
authors.forename: Antonino
authors.initials: A
authors.lastname: Mulè
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Zannoni
authors.forename: Alfredo
authors.initials: A
authors.lastname: Pontecorvi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Santeusanio
authors.forename: Corrado
authors.initials: C
authors.lastname: Minimo
authors.forename: Guido
authors.initials: G
authors.lastname: Fadda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000379:methods*; D002116:Calcitonin / Q000235:genetics / Q000378:metabolism; D018276:Carcinoma, Medullary / Q000175:diagnosis* / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000235:genetics / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology
chemical_list: D002116:Calcitonin; D013954:Thyroglobulin