Association of a Wide Invasive Malignant Thymoma with Myastenia Gravis and Primary Hyperparathyroidism Due to Parathyroid Adenoma: Case Report and Review of the Literature

Abstract

There are few cases described in the world literature reporting an association of thymoma (with myasthenia gravis or not) with hyperparathyroidism. In these cases the hyperparathyroidism was due to the presence of an adenoma or hyperplasic parathyroid tissue either in the cervical region or in an ectopic intrathymic location.(12345) In other cases the syndrome of hypercalcemia was due to the secretion of parathyroid-related protein (PTHRP) (6) or parathyroid hormone (PTH) (7) by the thymoma itself. We report the first case, at the best of our knowledge, of a wide invasive malignant thymoma (type B3), associated with myasthenia gravis and hyperparathyroidism caused by parathyroid adenoma.

Resolution of primary hyperparathyroidism following surgical removal of cervical thymus

“…[7] Moreover, a few cases of concurrent thymus and parathyroid pathology, such as thymoma and parathyroid adenoma with or without miastenia gravis, are described in the literature. [8][9][10] We report a case of apparent PTH secretion from thymus tissue. In fact, the normalization of PTH serum levels after surgery, the post-operatory eucalcemic state and the absence of an increased uptake in the second and third post-operatory 99m Tc/ 99m Tc-MIBI scintiscan led us to hypothesize that the mass surgically removed overproduced PTH and was the cause of the PHTP.…”

Unexpected thymoma in a challenging case of hyperparathyroidism

“…Parathyroid adenoma and thymoma are uncommon diseases. However, the simultaneous presentation of both tumors has been described, sometimes with ectopic cervical thymus or mediastinal parathyroid 1‐5 pattern. This relationship could be explained based on common embryologic developmental since lower parathyroid glands and thymus originate from the third pharyngeal pouch; therefore, the parathyroid glands separated from thymus move posteriorly to the thyroid.…”

Rare association of thymoma, myasthenia gravis and sarcoidosis : a case report

“…Hypercalcemia in patients with thymoma can be seen due to the following reasons, namely, secretion of parathyroid-related protein (PTHrP) or PTH by the thymoma itself, coexistence of parathyroid adenoma or hyperplasia of parathyroid gland [ 7 ]. In these cases, PTH level is usually elevated.…”