A 64-year-old woman presents with nephrolithiasis and
primary hyperparathyroidism. Her family history is
unremarkable A Tc-99 sestamibi scan demonstrates a focus
of activity near the left lower pole of the thyroid gland. The
next step in her management should be
A. left neck exploration.
B. confirmatory 24-hour urinary calcium level.
C. neck ultrasound.
D. observation with repeat calcium and parathormone levels
in 6 months.
E. contrast-enhanced dynamic CT scan of the neck and
chest (4-dimensional CT).
https://twitter.com/DrATEFAHMED/status/1645517671960641552?s=20
ANSWER: C
The diagnostic workup for primary hyperparathyroidis (pHPTH) is relatively simple biochemically. The serum calcium level will be elevated with a concomitant
inappropriately elevated parathormone level (PTH).
Confirmatory testing can include elevated levels of urinary
calcium excretion, effectively ruling out familial
hypocalciuric hypercalcemia. A normal Vitamin D level will
exclude low levels as a cause of the elevated PTH level. Other
associated biochemical findings can include depressed serum
phosphate with a serum chloride-to-phosphate ratio of greater
than 33. Once the biochemical diagnosis of pHPTH is made,
further testing is unnecessary and the decision for surgery is
made in concert with a surgeon familiar with endocrine
surgery. Criteria for surgical intervention are well established
in pHPT. In general, the symptomatic patient or the patient
with evidence of organ dysfunction from hypercalcemia
should have a parathyroidectomy.
The decision for further imaging is based solely on the
operative technique planned. If traditional 4-gland neck
exploration is planned, no further imaging is necessary. In the
hands of an experienced surgeon, additional imaging only
increases costs without significant benefit. If a patient is a
candidate for focused parathyroidectomy, or "minimally
invasive" parathyroidectomy, imaging techniques to localize
a solitary adenoma are appropriate. The sensitivity of Tc-99
sestamibi scan ranges from 65 to 85% and varies across
institutions widely. More importantly, the relatively low
specificity of any single imaging test to diagnosis a solitary
adenoma, as opposed to multiple adenomas or hyperplastic
disease, is not sufficient to guide focused surgical techniques.
Most experienced surgeons use a 2-imaging test algorithm,
and if concordant and confirmatory of solitary adenoma,
focused exploration may be appropriate. It is inappropriate to
offer focused parathyroidectomy based on a single positive
image or discordant imaging results. The most commonly
used imaging tests to guide exploration options, from least
expensive to most expensive, are neck ultrasonography, Tc-
99 sestamibi scanning, and contrast-enhanced CT scan of the
neck. Ultrasonographic imaging of the neck is inexpensive,reliable in experienced hands, and office based. It has the
added benefit of ruling out any additional thyroid pathology
in the setting of planned neck exploration
A 64-year-old woman presents with nephrolithiasis and
primary hyperparathyroidism. Her family history is
unremarkable A Tc-99 sestamibi scan demonstrates a focus
of activity near the left lower pole of the thyroid gland. The
next step in her management should be
A. left neck exploration.
B. confirmatory 24-hour urinary calcium level.
C. neck ultrasound.
D. observation with repeat calcium and parathormone levels
in 6 months.
E. contrast-enhanced dynamic CT scan of the neck and
chest (4-dimensional CT).
https://twitter.com/DrATEFAHMED/status/1645517671960641552?s=20
ANSWER: C
The diagnostic workup for primary hyperparathyroidis (pHPTH) is relatively simple biochemically. The serum calcium level will be elevated with a concomitant
inappropriately elevated parathormone level (PTH).
Confirmatory testing can include elevated levels of urinary
calcium excretion, effectively ruling out familial
hypocalciuric hypercalcemia. A normal Vitamin D level will
exclude low levels as a cause of the elevated PTH level. Other
associated biochemical findings can include depressed serum
phosphate with a serum chloride-to-phosphate ratio of greater
than 33. Once the biochemical diagnosis of pHPTH is made,
further testing is unnecessary and the decision for surgery is
made in concert with a surgeon familiar with endocrine
surgery. Criteria for surgical intervention are well established
in pHPT. In general, the symptomatic patient or the patient
with evidence of organ dysfunction from hypercalcemia
should have a parathyroidectomy.
The decision for further imaging is based solely on the
operative technique planned. If traditional 4-gland neck
exploration is planned, no further imaging is necessary. In the
hands of an experienced surgeon, additional imaging only
increases costs without significant benefit. If a patient is a
candidate for focused parathyroidectomy, or "minimally
invasive" parathyroidectomy, imaging techniques to localize
a solitary adenoma are appropriate. The sensitivity of Tc-99
sestamibi scan ranges from 65 to 85% and varies across
institutions widely. More importantly, the relatively low
specificity of any single imaging test to diagnosis a solitary
adenoma, as opposed to multiple adenomas or hyperplastic
disease, is not sufficient to guide focused surgical techniques.
Most experienced surgeons use a 2-imaging test algorithm,
and if concordant and confirmatory of solitary adenoma,
focused exploration may be appropriate. It is inappropriate to
offer focused parathyroidectomy based on a single positive
image or discordant imaging results. The most commonly
used imaging tests to guide exploration options, from least
expensive to most expensive, are neck ultrasonography, Tc-
99 sestamibi scanning, and contrast-enhanced CT scan of the
neck. Ultrasonographic imaging of the neck is inexpensive,reliable in experienced hands, and office based. It has the
added benefit of ruling out any additional thyroid pathology
in the setting of planned neck exploration