Pre-operative Tc-99m sestamibi parathyroid scan and bone scintigraphy in a case of synchronous parathyroid carcinoma and papillary microcarcinoma

ABSTRACT

Background@#Parathyroid carcinoma is an uncommon, aggressive, endocrine malignant neoplasm and subsequent parathyroidectomy of such cases may lead to the life-threatening hypocalcemic condition called Hungry Bone Syndrome. We present a very rare case of parathyroid carcinoma with concomitant thyroid microcarcinoma with Hungry Bone Syndrome as its sequalae.@*Case Presentation@#A 54/F initially presenting with hypogastric pain was showed to have nephrolithiasis. Subsequent Endocrinology referral revealed hypercalcemia and osteoporosis – and with a working impression of hypercalcemia secondary to a parathyroid adenoma. Sestamibi parathyroid scan showed persistently avid uptake in the left thyroid lobe highly suspicious for a parathyroid adenoma, but a concomitant thyroid nodule was not ruled out. Bone scan showed intense and diffuse tracer uptake in the skull and irregular tracer activity in the ribs, suggestive of metabolic bone disease, with no evidence of metastatic-looking bone lesions. She underwent left thyroid lobectomy with isthmusectomy and Sestamibi-guided left parathyroidectomy. Histopathology report showed a parathyroid gland carcinoma with papillary thyroid microcarcinoma. Two weeks post-surgery, hypocalcemic signs developed and ionized calcium was low. Hungry Bone Syndrome was considered and was treated with calcium gluconate and Zoledronic acid.@*Conclusion@#Nuclear imaging techniques and radioguided surgery are helpful in the diagnosis and management of both parathyroid and thyroid lesions – especially in difficult cases.