Diagnostic ultrasound ( PDFDrive )

CHAPTER
20
The Parathyroid Glands
Bonnie J. Huppert and Carl Reading
SUMMARY OF KEY POINTS
• In the vast majority of cases, primary hyperparathyroidism
is caused by hyperfunction of a single parathyroid gland
due to adenoma, much less commonly due to multiple
gland involvement.
• Surgical removal of the abnormal gland is the only
deinitive treatment for primary hyperparathyroidism, and
selective, minimally invasive surgical techniques are most
commonly used for irst-time surgery.
• The role of parathyroid imaging is not in the diagnosis of
primary hyperparathyroidism but rather to provide accurate
adenoma localization to successfully direct selective
surgical parathyroid resection.
• When used by an experienced examiner, parathyroid
sonography can provide high-resolution anatomic imaging
with good sensitivity and accuracy which is noninvasive,
lacks radiation exposure, is relatively low cost, and has the
added ability to assess for concomitant thyroid disease
prior to surgery.
• In persistent or recurrent hyperparathyroidism, liberal use
of multimodality preoperative imaging is particularly
beneicial prior to reoperation.
• In selected cases, ultrasound can also be used to guide
biopsy of suspected parathyroid adenomas to provide
preoperative conirmation and to guide ablation of
abnormal parathyroid glands in patients who are not
surgical candidates.
CHAPTER OUTLINE
EMBRYOLOGY AND ANATOMY
PRIMARY HYPERPARATHYROIDISM
Prevalence
Diagnosis
Pathology
Treatment
SONOGRAPHIC APPEARANCE
Shape
Echogenicity and Internal Architecture
Vascularity
Size
Multiple Gland Disease
Carcinoma
ADENOMA LOCALIZATION
Sonographic Examination and Typical
Locations
Ectopic Locations
Retrotracheal/Retroesophageal
Adenoma
Mediastinal Adenoma
Intrathyroid Adenoma
Carotid Sheath/Undescended
Adenoma
PERSISTENT OR RECURRENT
HYPERPARATHYROIDISM
SECONDARY
HYPERPARATHYROIDISM
PITFALLS IN INTERPRETATION
False-Positive Examination
False-Negative Examination
ACCURACY IN IMAGING
Ultrasound
Other Modalities
Importance of Imaging in Primary
Hyperparathyroidism
INTRAOPERATIVE SONOGRAPHY
PERCUTANEOUS BIOPSY
ETHANOL ABLATION
High-frequency sonography is a well-established, noninvasive
imaging method used in the evaluation and treatment of
patients with parathyroid disease. Sonography is oten used for
the preoperative localization of enlarged parathyroid glands or
adenomas in patients with hyperparathyroidism. Ultrasound is
also used to guide the percutaneous biopsy of suspected parathyroid
adenomas or enlarged glands, particularly in patients
with persistent or recurrent hyperparathyroidism, as well as in
some patients with suspected ectopic glands. In select patients,
sonography can be used to guide the percutaneous ethanol
ablation of parathyroid adenomas as an alternative to surgical
treatment.
EMBRYOLOGY AND ANATOMY
he paired superior and inferior parathyroid glands have diferent
embryologic origins, and knowledge of their development aids
in understanding their ultimate anatomic locations. 1-3 he
superior parathyroid glands arise from the paired fourth
branchial pouches (clets), along with the lateral lobes of the
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