FINE NEEDLE
ASPIRATION AND PARATHORMONE (PTH) MEASUREMENT IN THE RINSE MATERIAL – USEFULNESS
AND INDICATION
Ultrasound-guided
fine-needle aspiration (FNA) with cytology and PTH measurement should be considered
when an abnormality of uncertain nature is identified on ultrasonography,
especially when sestamibi scintigraphy is negative. PTH analysis in rinse material
obtained from FNA may be useful to discriminate thyroid nodules from enlarged
parathyroid glands (especially in cases of nondiagnostic cytology) and to
facilitate preoperative localization. Specificity and sensitivity of this
technique range from 90 to 100 %. Results of PTH measurement in rinse material
should be compared with serum PTH levels, since an elevated PTH in the serum
could falsely elevate PTH in the washout material if the rinse is contaminated
with blood. Obviously, in these cases, only PTH values significantly higher
than the serum should be considered as true positives. PTH < 100 pg/mL indicates
the absence of PTH-secreting tissue at the biopsied site. PTH> 100 pg/mL
indicates the presence of PTH-secreting tissue at the site biopsied or along
the needle track. Results depend on accurate sampling and the total needle wash
volume (each FNA needle from a single biopsied are should be washed with a very
small amount of normal saline (0.1 to 0.5 mL).
Σχόλια
Δημοσίευση σχολίου