Multiple gland disease (MGD) underlies primary hyperparathyroidism in 5-33% of cases1. It can be difficult to identify with current imaging modalities, and confers a higher risk of post-operative recurrence. One study has shown surgically confirmed MGD was detected by sestamibi-SPECT and ultrasound in 0% and 14% of cases respectively2. Detection rates improved with four-dimensional computed tomography (4D-CT) to only 32%. As inconclusive imaging is highly predictive of MGD1, bilateral neck exploration has been advocated as first line surgical management to reduce the risk of disease recurrence when compared to minimally invasive parathyroidectomy. The risk of hungry bone syndrome (HBS) post-operatively may also be increased in MGD, due to greater combined weight and volume of resected parathyroids3.
A 54-year-old female was diagnosed with primary hyperparathyroidism following investigation for chronic asymptomatic hypercalcaemia with osteoporosis. Minimally invasive right inferior parathyroidectomy was performed following suggestion of a single adenoma on ultrasound and sestamibi-SPECT, later confirmed on histopathology. Persistent hyperparathyroidism was investigated with 4D-CT, which did not demonstrate any residual disease. However, repeat ultrasound and sestamibi-SPECT suggested a parathyroid adenoma at the right lower thyroid pole, near the site of previous resection.
Subsequent exploratory surgery confirmed the presence of right intra-thyroidal parathyroid tissue. Her post-operative course was complicated by hungry bone syndrome with high calcium and vitamin D requirement. Over the following year, significant gain in bone mineral density was observed, particularly at the hip and lumbar spine.
Multiple gland disease is a challenging pre-operative diagnosis due to current limitations in imaging localisation. Inconclusive imaging should prompt consideration of exploratory surgery, rather than a minimally invasive approach, to mitigate the risk of disease persistence or recurrence. Recognition and aggressive management of hungry bone syndrome is essential, particularly in those at higher risk.