title: Neuroendocrine thymic carcinoma metastatic to the parathyroid gland that was reimplanted into the forearm in patient with multiple endocrine neoplasia type 1 syndrome: a challenging management dilemma.
abstract: OBJECTIVE
  To describe a unique case of a metastatic thymic carcinoma to the hyperplastic parathyroid gland and to present a challenging management dilemma.
  
  
  METHODS
  Our patient is 60-year-old, intellectually disabled man with history of the multiple endocrine neoplasia type 1 (MEN1) syndrome, a surgery in 1985 for hypercalcemia with removal of one parathyroid gland, surgery in 2007 with findings of extensively necrotic well differentiated neuroendocrine carcinoma (carcinoid tumor) of the thymus. In 2012, he presented with persistent hypercalcemia (calcium level 11.7 mg/dL [range, 8.6-10.2]), and a parathyroid hormone (PTH) level of 225 pg/mL (range, 15-65 pg/mL). He underwent a repeat neck exploration with removal of 2 small inferior and a large left superior 4.5 × 2.5 × 1.5 cm parathyroid glands, all of which showed hyperplasia on intraoperative frozen section. A small portion of the superior gland was reimplanted into the patient's forearm. Final pathology showed the presence of a focus of neuroendocrine tumor within the left superior parathyroid gland with immunostain identical to the thymic carcinoma. His postoperative PTH level was 14 pg/mL and calcium 8.5 mg/dL. A positron emission tomography-computed tomography (PET-CT) and octreotide scans revealed an extensive metastatic disease within the lung, mediastinum, and bones.
  
  
  RESULTS
  We decided to leave a portion of the reimplanted parathyroid gland with possible metastatic thymic carcinoid in his forearm because of the presence a widespread metastatic disease and his intellectual disability that would result in noncompliance with calcium replacement in case of permanent hypocalcemia.
  
  
  CONCLUSIONS
  Metastatic thymic carcinoma to the parathyroid gland has never been reported in the literature. We have described the first case and presented a challenging management dilemma.
authors.affiliation: Department of Surgery, Jersey Shore University Medical Center, Neptune, New Jersey.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Shifrin
authors.forename: Virginia A
authors.initials: VA
authors.lastname: LiVolsi
authors.forename: Min
authors.initials: M
authors.lastname: Zheng
authors.forename: Danielle E
authors.initials: DE
authors.lastname: Lann
authors.forename: Svetlana
authors.initials: S
authors.lastname: Fomin
authors.forename: Evan C
authors.initials: EC
authors.lastname: Naylor
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Mencel
authors.forename: Angela M
authors.initials: AM
authors.lastname: Fay
authors.forename: Brian S
authors.initials: BS
authors.lastname: Erler
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Matulewicz
mesh_terms: D005542:Forearm / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008607:Intellectual Disability; D008297:Male; D008875:Middle Aged; D018761:Multiple Endocrine Neoplasia Type 1 / Q000473:pathology*; D009333:Neck / Q000601:surgery; D009336:Necrosis; D009368:Neoplasm Transplantation; D010281:Parathyroid Hormone / Q000378:metabolism; D010282:Parathyroid Neoplasms / Q000556:secondary* / Q000601:surgery; D010375:Pedigree; D049268:Positron-Emission Tomography; D013945:Thymoma / Q000473:pathology*; D013953:Thymus Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed
chemical_list: D010281:Parathyroid Hormone