PMC7689332_01
Timeline and sequence of events over 3 years.. Normal values: Calcium (2.15-2.50 mmol/L), PTH (10-65 pg/mL), Albumin (35-50 g/L), Vitamin D (35-80 ng/mL), GFR (> 60 mL/min), Creatinine (44-97 mumol/L), 24-h urine calcium (2.50-7.50 mmol/L per 24 h), TSH (0.4-4.0 mIU/L).
gr1.jpg
PMC7689332_01_gr1.jpg
fig0005
Past medical history (Fig. 1A) was significant for chronic generalized lymphadenopathy and recurrent lower bilateral lower limb swelling (possible lymphedema). On initial admission to the medical team, a hypercalcemia workup was done (Fig. 1B). A diagnosis of primary hyperparathyroidism was made which warranted imaging of the PG (Fig. 1B). She was referred urgently to our thyroid surgery clinic, and was 18 weeks pregnant with hypercalcemia due to primary hyperparathyroidism associated with subclinical hyperthyroidism which was managed with beta blocker only (Fig. 1C). The patient was then seen and admitted to our surgical team (index admission, Fig. 1D). Apart from her high serum calcium and PTH, laboratory tests and renal function were within normal, and based on the previous sestamibi scan and CT (Fig. 1B, and Fig. 2, Fig. 3), the diagnosis of primary hyperparathyroidism due to EPA (paraoesophageal) was confirmed. Frozen sections histologically confirmed PA, and intraoperative rapid PTH monitoring before excision and 10 min after excision of the PA, showed a serum PTH decrease by 98% (Fig. 1E) confirming the removal of the hypersecreting gland (Fig. 4). On the first postoperative day, the patient developed mild symptoms and signs of hypocalcemia, the laboratory findings revealed low intact PTH (1 pg/mL) and serum calcium (1.9 mmol/L), and she was given treatment (Fig. 1F). A week later, follow up at our thyroid surgery clinic revealed that the patient did not complain of any of the symptoms of hypercalcemia experienced prior to surgery, or symptoms of hypocalcemia that developed in the early post-operative period, and she had normal laboratory findings (Fig. 1G), and histopathology showed findings consistent with hypercellular parathyroid tissue, compatible with PA (1.5 x 0.7 x 0.4 cm) weighting 0.1 g.
Early and late 99mTc-sestamibi scintigraphy parathyroid scan images of neck and mediastinum anteriorly at 20 min and 2 h showing increased focal uptake suggestive of right inferior parathyroid adenoma.
gr2.jpg
PMC7689332_01_gr2.jpg
fig0010
Ultrasound (US) of the neck did not identify parathyroid lesions; an earlier 99mTc-sestamibi scan (sestamibi scan) undertaken before her current pregnancy (Fig. 2) revealed activity at the lower pole of the right thyroid lobe suggesting a right inferior PA; and, her CT scan taken a year earlier (Fig. 3) as work up for generalized lymphadenopathy showed an ectopic right inferior paraesophageal parathyroid lesion (7 mm diameter) impressive of right inferior PA.
A Coronal, B axial and C sagittal views CT scan of the neck showing the ectopic parathyroid adenoma (red arrow) located in a paraoesophageal position, trachea (green arrow) and esophagus (blue arrow).
gr3.jpg
PMC7689332_01_gr3.jpg
fig0015
Apart from her high serum calcium and PTH, laboratory tests and renal function were within normal, and based on the previous sestamibi scan and CT (Fig. 1B, and Fig. 2, Fig. 3), the diagnosis of primary hyperparathyroidism due to EPA (paraoesophageal) was confirmed.