Background/Aim. Parathyroid hyperplasia (PHP) is defined as an absolute
increase in the mass of parenchymal cells of the parathyroid gland. PHP is
classified as primary, secondary and tertiary. The enlargement of parathyroid
glands (PG) is usually asymmetric, resulting in a ?dominant? gland. In order
to confirm the diagnosis, at least two glands should be examined
histologically. Subtotal parathyroidectomy, i.e. removal of the three PG and
leaving a small remnant of the forth, is the treatment of choice. High
percent of PHP recurrence imposes the need for preoperative high sensitivity
localizing procedures. Parathyroid scintigraphy localizes about 60% of
hyperplastic glands. The aim of this study was to correlate findings of
subtraction parathyroid scintigraphy (SPS) with weight, pathohistologic
finding and oxyphil cell (OC) content of PG in patients with primary,
secondary and tertiary parathyroid hyperplasia. Methods. Twenty-seven
patients with primary/secondary PHP underwent SPS before surgery.
Scintigraphic results were graded from 1-5, in relation to the degree of
uptake. SPS graded 3, 4 and 5 were considered positive. The number and weight
of operated PG were evaluated macroscopically. Pathohistologic and cellular
types were defined on standard stained hematoxylin-eosin slides. OC content
was defined as a percent of OC and graded from 1 to 3: grade 1 < 10%, grade 2
? 10% and grade 3 ? 20% of OC. Results. SPS localized dominant gland in all
patients with sensitivity 100%, and 51 from 73 hyperplastic PG, with
sensitivity per gland of 70%. PG weighed 0.1 g to 6.7 g (median 1 g). A
significant positive correlation (p < 0.0001) was found between the SPS
results and PG weight. A significant positive correlation was found between
PG weight and OC content (p = 0.0002). An insignificant correlation was found
between SPS and OC content. Thirty-eight PG had < 10% of OC, 32 PG had < 10%
and 3 PG had ? 20% of OC. Four patients had diffuse PHP and 23 patients
nodular PHP. There was no statistically significant difference in SPS results
compared to hyperplasia type, and between OC content and hyperplasia type. A
significant positive correlation (p = 0.05) was found between PG weight and
hyperplasia type. Conclusion. A high positive correlation was found between
SPS results and PG weight, PG weight and OC content and PG weight and
hyperplasia type. Between SPS results and OC content, and between SPS results
and hyperplasia type, an insignificant correlation was found. Our results
showed that SPS is a reliable and very sensitive diagnostic tool in detecting
abnormal PG in parathyroid hyperplasia, reaching 100% sensitivity in
detecting a ?dominant gland? and sensitivity per localized gland of 70%.
Causes that affect increased uptake of liposolubile Tc99m
radiopharmaceuticals (RF) in the hyperfunctional PG tissue and conditions
which prevent RF admission into the PG cells still remain to be accurately
and precisely determined.
Oxyphil Cell