title: A large functioning parathyroid cyst in a patient with multiple endocrine neoplasia type 1.
abstract: A 62-year-old woman presented with a mass on the left side of the neck. Biochemical testing revealed primary hyperparathyroidism. Further, a prolactinoma was detected, and the patient's son and daughter also had primary hyperparathyroidism, indicating that the patient had multiple endocrine neoplasia type 1 (MEN1). Neck ultrasonography revealed several cystic nodules (≤ 30 mm) that appeared to be adenomatous. After parathyroidectomy with autotransplantation, the largest cystic mass, in the left lower thyroid lobe, was pathologically diagnosed as a functioning parathyroid cyst, and all laboratory data returned to normal. On genetic analysis of blood, we found a novel single base insertion (duplication) in exon 10 codon 552 of the MEN1 gene (c1659dupT) that creates an early stop codon. This is the first case report of a parathyroid cyst resulting from parathyroid hyperplasia in a MEN1 patient.
authors: Division of Endocrinology, Toranomon Hospital Endocrine Center, Tokyo 105-8470, Japan. tamiyah-tky@umin.ac.jp
authors: Hiroyuki
authors: H
authors: Tamiya
authors: Megumi
authors: M
authors: Miyakawa
authors: Hisanori
authors: H
authors: Suzuki
authors: Akira
authors: A
authors: Takeshita
authors: Kenichi
authors: K
authors: Ohashi
authors: Takeshi
authors: T
authors: Usui
authors: Daishu
authors: D
authors: Miura
authors: Yasuhiro
authors: Y
authors: Takeuchi
mesh_terms: D000236:Adenoma / Q000150:complications / Q000175:diagnosis; D003560:Cysts / Q000150:complications* / Q000175:diagnosis; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000175:diagnosis / Q000209:etiology*; D008875:Middle Aged; D018761:Multiple Endocrine Neoplasia Type 1 / Q000150:complications* / Q000175:diagnosis; D010282:Parathyroid Neoplasms / Q000150:complications* / Q000175:diagnosis; D010911:Pituitary Neoplasms / Q000150:complications / Q000175:diagnosis; D015175:Prolactinoma / Q000150:complications / Q000175:diagnosis