Association of parathyroid carcinoma and thyroid disorders: A clinical review

Parathyroid carcinoma is a rare malignancy, which usually occurs as a sporadic disease, and less frequently in the setting of genetic syndromes. Despite the association of parathyroid and thyroid disorders being quite common, the coexistence of parathyroid carcinoma and thyroid disease is rare. We reviewed the pertinent literature. The terms "parathyroid carcinoma" and "thyroid disease, hyperthyroidism, thyrotoxicosis, hypothyroidism, thyroid nodule(s), Graves' disease, autonomously functioning thyroid nodules" were used both separately and in reciprocal conjunction to search MEDLINE for articles published from January 2007 to March 2016. The search was prompted by the observation of a never reported association of autonomously functioning thyroid nodules and parathyroid carcinoma. Two hundred and twenty-one parathyroid carcinoma patients have been described during the last 10 years. Neck ultrasonography and parathyroid scintigraphy are the most common instrumental studies used in detecting parathyroid lesions. Serum parathyroid hormone and calcium levels are high in the majority of parathyroid carcinoma patients. Only 21 patients with parathyroid carcinoma and thyroid disorders were found. Our patient is the first casual association between parathyroid carcinoma and autonomously functioning thyroid nodules reported in literature and diagnosed using parathyroid and thyroid scintigraphies. Parathyroid carcinoma is a very rare endocrine tumor and association with thyroid disease is not frequent. Parathyroid carcinoma pre-operative diagnosis is often difficult also because available literature data are not homogenous and there is not a common operative guideline. Our case confirms the role of parathyroid scintigraphy, encouraging the association with thyroid scintigraphy, especially in the presence of (multi)-nodular goiter in order to address the most appropriate surgical management.