Diagnostic ultrasound ( PDFDrive )

744 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
Occasionally, for patients who are not candidates for repeat
surgery, ultrasound-guided percutaneous ethanol injection may
be used for ablation of recurrent hyperparathyroid disease in the
neck or at a grat site (see “Ethanol Ablation”).
A rare cause of persistent or recurrent hyperparathyroidism
is parathyromatosis, a condition in which multiple foci of benign
hyperfunctioning parathyroid tissue are present in the neck and/
or mediastinum. 66,67 he theory of most common pathogenesis
is inadvertent spillage and seeding of parathyroid cells during
parathyroid excision. However, rare cases of hyperplasia of
preexisting embryologic rests under the inluence of physiologic
stimuli have also been described. 66-70 he condition is most
commonly seen in patients with a history of previous parathyroid
surgery and those with secondary hyperparathyroidism resulting
from chronic renal disease. 71 Sonographic imaging in the setting
of recurrent hyperparathyroidism ater previous parathyroid
resection may demonstrate multiple hypoechoic to isoechoic
neck nodules of varying size in locations atypical for missed
parathyroid disease. Larger nodules may display hypervascularity,
parasitized from local vessels 72 (Fig. 20.15, Video 20.13).
SECONDARY HYPERPARATHYROIDISM
Secondary hyperparathyroidism is characterized by pronounced
parathyroid gland hyperfunction resulting from end-organ
resistance to PTH and is most oten found in patients with chronic
A
B
C
D
FIG. 20.15 Parathyromatosis in Persistent Primary Hyperparathyroidism. (A) Transverse sonogram of the right side of the neck in a patient
with persistent primary hyperparathyroidism despite multiple surgeries for parathyroid and thyroid resection shows a 7-mm hypoechoic nodule
(calipers) representing hyperfunctioning benign parathyroid tissue between the trachea (Tr) and common carotid artery (C). (B) Transverse sonogram
of the left side of the neck shows a similar-appearing 7-mm hypoechoic nodule (cursors) representing hyperfunctioning benign parathyroid tissue
between the trachea and common carotid artery. (C) Transverse sonogram of the midline upper neck shows a 3 × 6–mm hypoechoic nodule
representing hyperfunctioning benign parathyroid tissue. T, Trachea. (D) Corresponding color Doppler low sonogram demonstrates peripheral parasitized
hypervascularity (arrow). See also Video 20.13.