title: Neuroendocrine tumors presenting with thyroid gland metastasis: a case series.
abstract: BACKGROUND
  Autopsy series have shown that metastasis to the thyroid gland has occurred in up to 24% of patients who have died of cancer. Neuroendocrine tumors may metastasize to thyroid gland.
  
  
  METHODS
  Case 1 was a 17-year-old Turkish woman who was referred from our Endocrinology Department for a thyroidectomy for treatment of neuroendocrine tumor metastasis. She was treated with a bilateral total thyroidectomy. Histopathological examination results were consistent with a neuroendocrine tumor; neoplastic cells showed strong immunoreactivity to chromogranin A and synaptophysin, but the immunohistochemical profile was inconsistent with medullary thyroid carcinoma in that the tumor was negative for calcitonin, carcinoembryonic antigen, and thyroid transcription factor-1.Case 2 was a 54-year-old Turkish woman who presented with a 3-cm nodule on her right thyroid lobe. She had undergone surgery for a right lung mass four years previously. After a right pneumonectomy, thymectomy and lymph node dissection, a typical carcinoid tumor was diagnosed. Under ultrasonographic guidance, fine needle aspiration biopsy of her right thyroid pole nodule was performed and the biopsy was compatible with a neuroendocrine tumor metastasis. She was treated with a bilateral total thyroidectomy. Histopathological examination indicated three nodular lesions, 5 cm and 0.4 cm in diameter in her right lobe and 0.1 cm in diameter in her left lobe. The tumors were consistent with a neuroendocrine phenotype, showing strong immunoreactivity to chromogranin A and synaptophysin.
  
  
  CONCLUSIONS
  Thyroid nodules detected during follow-up of neuroendocrine tumor patients should be thoroughly investigated. A fine needle aspiration biopsy of the thyroid confirms the diagnosis in most cases and leads to appropriate management of those patients and may prevent unnecessary treatment approaches.
authors.affiliation: Department of General Surgery, Istanbul University, Istanbul Medical School, Capa-Istanbul 34093, Turkey. drbkaya@yahoo.com.
authors.forename: Emre
authors.initials: E
authors.lastname: Sivrikoz
authors.forename: Nese Colak
authors.initials: NC
authors.lastname: Ozbey
authors.forename: Bulent
authors.initials: B
authors.lastname: Kaya
authors.forename: Yesim
authors.initials: Y
authors.lastname: Erbil
authors.forename: Serkan
authors.initials: S
authors.lastname: Kaya
authors.forename: Dilek
authors.initials: D
authors.lastname: Yilmazbayhan
authors.forename: Pinar
authors.initials: P
authors.lastname: Firat
authors.forename: Yersu
authors.initials: Y
authors.lastname: Kapran