Preoperational Fine Needle Aspiration of Pathological Parathyroid Gland

Identification and localization of pathological parathyroid gland before parathyroidectomy is traditionally done by a combination of two methods: ultrasound and sestamibi scan. The investigators would like to show that one exam that includes ultrasound and fine needle aspiration of the parathyroid gland for parathyroid hormone level is as accurate as the traditional method.

A prospective, open label, single arm trial that includes participants that suffer hypercalcemia due to primary hyperparathyroidism and are candidates for parathyroidectomy.

participants visit the investigator's head and neck clinic. the investigator confirms that the participant has an indication for parathyroidectomy according to the official criteria. Later on, the investigator looks at the localization tests that have already been done (neck ultrasound and MIBI \[methoxyisobutyllisonitrile\] scan) in order to plan the surgery. In case participant has not made those tests- the investigator fills a written request to do so. then, the investigator will perform a neck ultrasound and identifies the pathological parathyroid gland. The suspected pathological gland is aspirated using a 27 gauge needle attached to a 5 cc syringe fills with 1 cc saline (0.9% NaCL) under the guidance of the ultrasound. The aspirated material is sent for 2 examinations:

1. parathyroid hormone level: the aspirated material is injected into a ethylenediaminetetraacetic acid (EDTA) vial and send to the hospital's endocrine laboratory. the parathyroid hormone level is processed using chemiluminescence method and represented in Pg/ml units.
2. cytology examination. The aspirated material is spread on a glassed slide and prepared with a Giemsa stain for a cytologic examination. cytologic features such as cell type, cytoplasmic characteristics,cell block structure and chromatin appearance is addressed by the pathologist.

After completion of the ultrasound - guided needle aspiration the participant is given an exact date for the surgery.

The surgery is carried out routinely with the same surgical steps that the investigator is familiar with. At the end of surgery, after the pathological parathyroid gland was extracted from the neck, it is aspirated with a 27Gy needle attached to a 5 cc, syringe filled with a 1 cc saline (0.9% NaCL).

The aspirated material is sent to the same, above mentioned, examinations (parathyroid hormone level and cytology).

After the investigator receives the final pathological result of the suspected gland and confirm that the excised tissue was indeed a pathological parathyroid one, the investigators are able to answer 2 important questions:

1. Is high level of parathyroid hormone which was aspirated from a suspected pathological parathyroid tissue is a good indicator that the tissue is indeed a pathological parathyroid.
2. Is there a difference between parathyroid cytology of a tissue aspirated transcutaneously to a parathyroid cytology of material aspirated directly from the parathyroid gland.

Eligibility Criteria:
Inclusion Criteria:

* above 18 years old
* participants that suffer from primary hyperparathyroidism with an indication for parathyroidectomy

Exclusion Criteria:

* Chronic renal failure
* kidney transplant participant
* MEN (multiple endocrine neoplasia) syndrome
* pregnancy