title: Intraoperative determination of PTH concentrations in fine needle tissue aspirates to identify parathyroid tissue during parathyroidectomy.
abstract: BACKGROUND
  Exact tissue identification during parathyroidectomy is essential to successfully cure hyperparathyroidism. PTH level determination from tissue aspirates has been advocated as a "biochemical frozen section" for parathyroid tissue identification. We investigated the sensitivity and specificity of this method in a large cohort of consecutive patients who underwent parathyroidectomy in a tertiary referral center.
  
  
  METHODS
  PTH levels of 359 tissue aspirates were measured intraoperatively in 223 consecutive patients from March 2006 to December 2008. Suspected parathyroid and control tissues were aspirated with a standardized technique immediately after their excision. Samples were processed for quick-PTH assay with peripheral blood samples before and after excision. PTH levels from tissue aspirates were correlated with pathological diagnosis. The Mann-Whitney test was used to determine statistical significance (P < 0.05).
  
  
  RESULTS
  A total of 255 parathyroid (196 adenoma, 30 hyperplasia, 4 carcinoma, 25 normal parathyroid) and 104 nonparathyroid tissue (88 thyroid, 16 lymph node, thymus, or fat) aspirates were compared. A highly significant difference was found between PTH levels of parathyroid (8,120 +/- 2,711 pg/ml; interquartile range (IQR): 4,949-9,075) and nonparathyroid (0.8 +/- 9.29 pg/ml; IQR: 0.4-1.4) tissue aspirates (P < 0.005). This test is 100% sensitive and 100% specific to identify parathyroid tissue for values >84 pg/ml. Furthermore, PTH levels of pathological parathyroid aspirates (8,169 +/- 2,597; IQR: 5,634-9,109) were higher than that of normal parathyroid aspirates (4,130 +/- 2,952; IQR: 2,569-8,284; P = 0.0011).
  
  
  CONCLUSIONS
  PTH level determination from tissue aspirates is a highly reliable, quick, and simple method to differentiate parathyroid and nonparathyroid tissues during parathyroidectomy. This method can obviate frozen sections in patients undergoing surgery for hyperparathyroidism.
authors.affiliation: 1st Department of Surgery, Semmelweis University, Ulloi út 78, 1082, Budapest, Hungary. hj@seb1.sote.hu
authors.forename: János
authors.initials: J
authors.lastname: Horányi
authors.forename: László
authors.initials: L
authors.lastname: Duffek
authors.forename: Rezso
authors.initials: R
authors.lastname: Szlávik
authors.forename: István
authors.initials: I
authors.lastname: Takács
authors.forename: Miklós
authors.initials: M
authors.lastname: Tóth
authors.forename: László
authors.initials: L
authors.lastname: Romics
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000737:chemistry* / Q000473:pathology; D010281:Parathyroid Hormone / Q000032:analysis*; D016105:Parathyroidectomy; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone