CASE 3186 Published on 01.12.2005

Parathyroid adenoma in a young patient with primary hyperparathyroidism

Section

Head & neck imaging

Case Type

Clinical Cases

Authors

Trieb T, Kovacs P, Gabriel M, Prommegger R, Bale RJ

Patient

13 years, male

Categories
No Area of Interest ; Imaging Technique Ultrasound-Colour Doppler, CT, SPECT
Clinical History
Due to a bilateral genu valgum, an osteotomy was performed on a patient; in the pre-operative examinations, an elevated Calcium blood level was detected.
Imaging Findings
The first clinical sign of this patient with hyperparathyroidism were the associated bilateral genu valgum. Other clinical symptoms like abnormal fatigue, nephrolithiasis or hypertonia didn´t lead to the diagnosis in this case, because this signs are unspecific. Skeletal abnormalaties on X-ray examination are often pathbreaking. The laboratory findings showed that the pathologic blood levels of calcium and phosphorus amounted to 4.43 mmol/L (normal range 2.10–2.70) and 0.66 mmol/L (0.95–1.75), respectively. An X-ray study of the left hand and the thorax was obtained. An ultrasound examination of the abdomen and of the head and neck was performed. The X-ray of the left hand showed sub and endosteal bone resorption along the middle phalanges. The thorax study showed a "Rugger-Jersey-Spine" which is almost diagnostic of hyperparathyroidism. The abdominal ultrasound imaging did not reveal any pathology (i.e. gall-bladder or renal calculi). US of the head and the neck showed a 1.5 x 2 cm sized hypoechogenic hypervascularized mass on the left caudal–dorsal edge of the thyroid gland. In contrast-enhanced CT the mass was hypodense with respect to the thyroid and showed a high tracer uptake in the MIBI scan. The diagnosis of a parathyroid adenoma was confirmed by minimal invasive parathyroidectomy. The intraoperative parathyroid hormone assay could predict successful unilateral surgery of a single adenoma. The outcome of the patient was excellent concerning the subjective well-being and the labaratory findings with normal blood levels of calcium and phosphorus (i.e. complete remission).
Discussion
The parathyroid glands are most commonly located dorsal to the middle one third of the thyroid (upper glands) and lateral to the lower pole of the thyroid gland (lower glands). As these glands arise from the fourth branchial pouch, they may descend to the anterior mediastinum as far as the pericardium. Surgery is the treatment of choice in symptomatic patients. For this reason, it is useful to identify enlarged parathyroid glands, to enable a minimal invasive surgical approach (i.e., unilateral neck exploration). The presence of solitary parathyroid adenomas accounts for up to 90% of the enlarged glands. The existence of one or more supernumerary pathological parathyroid glands is a major cause of surgical failure. To avoid bilateral opening of the carotid sheath or resection of the thymus, all pathological glands should be identified by pre-operative imaging. Functional as well as a rough anatomical information is given by 99m Tc-sestamibi/123I scintigraphy. The presence of hot spots suggests enlarged parathyroid glands; however, the spatial information localization is not very good. US and contrast-enhanced computed tomography performed on the patient clearly depicted the anatomy. The performance of CT is especially important to exclude multiglandular disease involving the mediastinum which is not detectable by US.
Differential Diagnosis List
Adenoma of the parathyroid gland.
Final Diagnosis
Adenoma of the parathyroid gland.
Case information
URL: https://www.eurorad.org/case/3186
DOI: 10.1594/EURORAD/CASE.3186
ISSN: 1563-4086