Diagnosticwork-up forsuspectedprimary hyperparathyroidism(performedin a peripheralhospital):
Normal neck US examination.
No parathyroid scintigraphy performed.
Measurement of bone mineral density (DEXA): i. vertebral BMD 0.8959 gr/cm2 (T score -1.2; Z score –1.1. ii. femoral BMD 0.656 gr/cm2 (T score -1.7; Z score –1.7).
24-hr urinary calcium: 388 mg (100-300).
No Vitamin D deficiency.
December 2008, Bilateral neck exploration:
No evidence of abnormal parathyroid glands.
Thymectomy performed because of suspected intra-thymic localization.
Histology: normal thymic tissue.
February 2009 (persistent hyperparathyroidism): Small nodule in thymic region (6×8 mm) detected on neck.
Teaching points:
The use of a pin-hole collimator in the neck increases image resolution.
The chest is best evaluated with a parallel-hole collimator either as a planar image or using SPECT (better topographic correlation).
SPECT(and especially SPECT/CT) is most helpful in evaluation of the mediastinumas the possible site of ectopic parathyroid glands.