Mediastinal giant parathyroid adenoma-a minimally invasive mediastinal surgical approach for an emergency presentation.

Abstract

A 72-year-old female was referred to our unit with a right sided hemothorax following biopsy of a paratracheal mass (Video 1). The patient was initially seen by her general practitioner for hypertension. Routine blood investigations revealed hypercalcemia, (calcium 2.00 mmol/L, adjusted calcium 3.02 mmol/L) and hypophosphatemia (phosphate 0.84 mmol/L). Parathyroid hormone (PTH) levels were significantly raised at 26.6 mmol/L. The patient had a background history of depression but was otherwise asymptomatic and physical examination was unremarkable. She was referred to an endocrinologist and investigated for primary hyperparathyroidism. The patient was found to be osteoporotic on dual energy X-ray absorptiometry (DEXA) scanning (T score =−3.2 at the lumbar spine). Neck ultrasound revealed an incidental thyroid nodule, but no obvious parathyroid lesion. A technetium sestamibi (99 mTc MIBI) scan showed no evidence of a parathyroid adenoma. Computed tomography (CT) revealed a complex cystic solid mass (Figure 1A) in the mediastinum, closely related to the right lateral aspect of the trachea, the esophagus, the superior vena cava (SVC) and the right subclavian artery and veins. A CT-guided biopsy (Figure 1B) was performed following multidisciplinary discussion, confirming a parathyroid adenoma on histology. The patient developed a right sided apical pneumothorax following the biopsy which was managed with a chest drain, and she was discharged. She was readmitted after one week, with a 3-day history of progressive shortness of breath but was hemodynamically stable. A repeat CT scan showed a large right pleural effusion (Figure 2) with no active contrast extravasation. The patient underwent drainage of the hemothorax with excision of the adenoma via video assisted thoracoscopy (VATS). The mass was found to be actively bleeding intraoperatively. Histology identified it as a 19-g mediastinal giant parathyroid adenoma macroscopically, with a large hemorrhage-filled cavity and a thick, calcified wall (Figure 3) and microscopically (Figure 4) without evidence of malignancy.