Cystic parathyroid glands in MEN1: A rare entity?

Abstract

Approximately 300 cases of sporadic parathyroid cyst (PCs) have been reported to date. Only two cases have been described in MEN1 so far. Detection by imaging could be challenging, especially in multiglandular primary hyperparathyroidism (HPT) and clinical outcome could be different. During the period 1990-2014, 71 MEN1 patients were operated for primary hyperparathyroidism in our centre. We report three cases of PCs in MEN1 patients affected by HPT, who underwent a total or subtotal parathyroidectomy with transcervical thymectomy. In our series, all three patients had an unsatisfactory postoperative course, at variance with the high percentage (over 90 %) of long-term success in MEN1 patients operated at our centre. One patient affected by cystic degeneration of all the four parathyroid glands reported persistent hypoparathyroidism, despite autografts of parathyroid tissue. For the other two cases, surgery failed to cure hyperparathyroidism, perhaps because of the presence of undetected ectopic parathyroid tissue. In the context of a multiglandular disease such as MEN1 syndrome, PCs seem rare but our experience shows about a 4 % incidence. Furthermore their presence, even in expert hands, could affect the preoperative identification of the parathyroid glands due to the difficult differential diagnosis between PC and other cystic lesions of the neck, and intraoperative detection of the glands as well as the postoperative outcome.

Multiple Endocrine Neoplasia Type 1 with Functional Parathyroid Cysts

“…Previous reports suggest that nonfunctional parathyroid cysts may arise from vestigial remnants of the third or fourth branchial cleft or coalescence of microcysts (17,18). For functional parathyroid cysts, a pre-existing parathyroid adenoma or carcinoma may cause cystic degeneration (16)(17)(18). In MEN1 cases, only five patients with parathyroid cysts have been previously reported (Table 3) (17)(18)(19).…”

“…However, the etiology contributing to the development of parathyroid cysts remains unclear. Previous reports suggest that nonfunctional parathyroid cysts may arise from vestigial remnants of the third or fourth branchial cleft or coalescence of microcysts (17,18). For functional parathyroid cysts, a pre-existing parathyroid adenoma or carcinoma may cause cystic degeneration (16)(17)(18).…”

Multiple Endocrine Neoplasia Type 1 Combined With Papillary Thyroid Carcinoma and Nodular Goiter: A Case Report and Review of The Literature

“…Our case provides practical evidence that MEN1 and thyroid tumors may coexist. MEN1 is a rare hereditary tumor syndrome inherited in an autosomal dominant manner and presents mostly as tumors of the parathyroid [15], endocrine pancreas (such as gastrinoma) [16] and anterior pituitary [17]. Other endocrine and nonendocrine lesions of MEN1, such as adrenal cortical tumors; carcinoids of the bronchi, gastrointestinal tract and thymus; lipomas; angio bromas; and collagenomas have been described [1,18].…”

“…Cavalli et al found that approximately 300 cases of sporadic parathyroid cyst (PCs) had been reported to 2017. Only two cases have been described in MEN1 [15]. Parathyroid cysts can be divided into functioning and nonfunctioning, and most parathyroid cysts are nonfunctioning.…”

Unusual presentations of functional parathyroid cysts: a case series and review of the literature

“…They are rarely found in the posterior mediastinum, but if they are found in the posterior mediastinum they mostly originate from superior parathyroid glands. In addition, some rare clinical presentations or associations have been described, such as parathyroid cyst in systemic lupus [ 32 ] or in type 1 multiple endocrine neoplasia, a condition frequently leading to functional parathyroid adenoma [ 33 ].…”