2. Case Report
A 41-year-old female presented to our institution for evaluation of
primary hyperparathyroidism. She had a 7-year history of hypercalcemia,
with levels up to 11.5 mg/dL (reference range: 8.7 - 10.2 mg/dL) and PTH
levels up to 101 pg/mL (reference range: 10 – 73 pg/mL).
She has no pertinent family
history and is a former smoker (0.25 ppd, 5 pack-years). Initially, she
underwent an ultrasound (US) of the neck and99mTc-MIBI single photon emission computed tomography
(SPECT) imaging, which failed to identify any suspicious lesions or
localizing parathyroid adenomas. Subsequent SPECT/CT (Figure 1 )
and 4-D computed tomography (CT) (Figure 2 ) demonstrated evidence
of a 1.3 cm lesion superior to the thyroid at the level of the pyriform
sinus on the left side, likely representative of an ectopic or
undescended parathyroid adenoma. Given its unusual location patient was
preoperatively counseled on the risk of injury to the hypoglossal nerve,
marginal mandibular nerve, and the possible need for a second incision
for four gland exploration if the candidate lesion was not an adenoma.
On the day of surgery, pre-operative PTH level was 80 pg/mL. In the
operating room, an upper transcervical incision was performed to obtain
access to the identified site. The subplatysmal flap was raised
superiorly and inferiorly to expose the inferior aspect of the
submandibular gland. Then the investing fascia was incised just caudal
to the submandibular gland, which was retracted superiorly to reveal the
posterior belly of the digastric muscle. The digastric muscle was
dissected along its anterior face and subsequently retracted superiorly
to identify the hypoglossal nerve and the internal jugular vein. A
crossing facial vein was encountered that required ligation to gain
appropriate access. An enlarged and undescended parathyroid measuring
1.5 x 1.5 cm located deep and slightly inferior to the anterior belly of
the digastric muscle, anterior and slightly medial to the carotid
artery, was identified and carefully resected (Figure 3, Figure
4 ). 10 minutes following the excision of the adenoma, PTH fell to 16
pg/mL and at 15 minutes post-excision remained stable at 14 pg/mL
indicating biochemical cure.