{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T10:18:05Z","timestamp":1788430685997,"version":"build-2803163510"},"reference-count":16,"publisher":"The Endocrine Society","issue":"10","license":[{"start":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T00:00:00Z","timestamp":1788393600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Parathyroid carcinoma is a rare cause of primary hyperparathyroidism (PHPT) and is often difficult to distinguish from benign parathyroid disease in its early stages. We describe a nearly 20-year clinical course of recurrent PHPT requiring 4 surgical interventions, ultimately culminating in the diagnosis of parathyroid carcinoma in a nonorthotopic supraclavicular location. The patient was followed continuously at our institution, allowing longitudinal assessment of biochemical, imaging, and histopathological findings. The initial surgery resulted in biochemical remission following removal of a parathyroid adenoma; however, hypercalcemia and elevated intact parathyroid hormone levels recurred over time. Subsequent resections demonstrated parathyroid-type proliferation with increasing Ki-67 index, and the final surgery revealed capsular and venous invasion consistent with carcinoma. Notably, technetium-99\u2005m methoxyisobutylisonitrile uptake became progressively weaker over time and eventually appeared as faint uptake in a nonorthotopic location. These findings may reflect changes in tumor biology over time. Although it remains uncertain whether the supraclavicular lesion represented an ectopic primary carcinoma or metastatic disease from an occult orthotopic lesion, this case highlights the diagnostic challenges of recurrent PHPT and the importance of long-term follow-up, reassessment of atypical locations, and careful interpretation of changing imaging and proliferative indices.<\/jats:p>","DOI":"10.1210\/jcemcr\/luag225","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T11:47:39Z","timestamp":1785930459000},"source":"Crossref","is-referenced-by-count":0,"title":["Parathyroid carcinoma in a nonorthotopic supraclavicular location: a 20-year course"],"prefix":"10.1210","volume":"4","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4576-4739","authenticated-orcid":false,"given":"Kimitaka","family":"Shibue","sequence":"first","affiliation":[{"name":"Department of Diabetes and Endocrinology, Medical Research Institute KITANO HOSPITAL, PIIF Tazuke-Kofukai , Kita-ku, Osaka 530-8480 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryo","family":"Tsukaguchi","sequence":"additional","affiliation":[{"name":"Department of Diabetes and Endocrinology, Medical Research Institute KITANO HOSPITAL, PIIF Tazuke-Kofukai , Kita-ku, Osaka 530-8480 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sachiko","family":"Honjo","sequence":"additional","affiliation":[{"name":"Department of Diabetes and Endocrinology, Medical Research Institute KITANO HOSPITAL, PIIF Tazuke-Kofukai , Kita-ku, Osaka 530-8480 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akihiro","family":"Hamasaki","sequence":"additional","affiliation":[{"name":"Department of Diabetes and Endocrinology, Medical Research Institute KITANO HOSPITAL, PIIF Tazuke-Kofukai , Kita-ku, Osaka 530-8480 ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"80","published-online":{"date-parts":[[2026,9,3]]},"reference":[{"issue":"12","key":"2026090305471488900_luag225-B1","doi-asserted-by":"crossref","first-page":"3679","DOI":"10.1210\/jc.2011-1571","article-title":"Parathyroid carcinoma: a 43-year outcome and survival analysis","volume":"96","author":"Harari","year":"2011","journal-title":"J Clin Endocrinol Metab"},{"issue":"5","key":"2026090305471488900_luag225-B2","doi-asserted-by":"crossref","DOI":"10.1093\/bjs\/znae108","article-title":"Consensus statement of the European Society of Endocrine Surgeons (ESES) on advanced parathyroid cancer: definitions and management","volume":"111","author":"Makay","year":"2024","journal-title":"Br J Surg"},{"issue":"25","key":"2026090305471488900_luag225-B3","doi-asserted-by":"crossref","first-page":"2389","DOI":"10.1056\/NEJMcp1106636","article-title":"Primary hyperparathyroidism","volume":"365","author":"Marcocci","year":"2011","journal-title":"N Engl J Med"},{"issue":"4","key":"2026090305471488900_luag225-B4","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1038\/ng1048","article-title":"HRPT2, encoding parafibromin, is mutated in hyperparathyroidism-jaw tumor syndrome","volume":"32","author":"Carpten","year":"2002","journal-title":"Nat Genet"},{"issue":"9","key":"2026090305471488900_luag225-B5","doi-asserted-by":"crossref","first-page":"2535","DOI":"10.1245\/s10434-018-6559-6","article-title":"Tumor size and presence of metastatic disease at diagnosis are associated with disease-specific survival in parathyroid carcinoma","volume":"25","author":"Lo","year":"2018","journal-title":"Ann Surg Oncol"},{"issue":"1","key":"2026090305471488900_luag225-B6","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1007\/s00268-012-1773-z","article-title":"Incidence and localization of ectopic parathyroid adenomas in previously unexplored patients","volume":"37","author":"Roy","year":"2013","journal-title":"World J Surg"},{"issue":"10","key":"2026090305471488900_luag225-B7","doi-asserted-by":"crossref","first-page":"604","DOI":"10.1055\/s-0032-1327628","article-title":"Ectopic parathyroid glands and their anatomical, clinical and surgical implications","volume":"120","author":"Noussios","year":"2012","journal-title":"Exp Clin Endocrinol Diabetes"},{"issue":"11","key":"2026090305471488900_luag225-B8","doi-asserted-by":"crossref","first-page":"2373","DOI":"10.1002\/jbmr.4689","article-title":"Surgical aspects of primary hyperparathyroidism","volume":"37","author":"Perrier","year":"2022","journal-title":"J Bone Miner Res"},{"issue":"5","key":"2026090305471488900_luag225-B9","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1210\/endrev\/bnad009","article-title":"Molecular and clinical spectrum of primary hyperparathyroidism","volume":"44","author":"Jha","year":"2023","journal-title":"Endocr Rev"},{"issue":"2","key":"2026090305471488900_luag225-B10","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1007\/s12022-018-9527-6","article-title":"Immunohistochemistry in diagnostic parathyroid pathology","volume":"29","author":"Erickson","year":"2018","journal-title":"Endocr Pathol"},{"key":"2026090305471488900_luag225-B11","volume-title":"Endocrine and Neuroendocrine Tumours","author":"WHO Classification of Tumours Editorial Board","year":"2022","edition":"5th ed."},{"key":"2026090305471488900_luag225-B12","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1159\/000491039","article-title":"Parathyroid carcinoma","volume":"51","author":"Cetani","year":"2019","journal-title":"Front Horm Res"},{"issue":"28","key":"2026090305471488900_luag225-B13","doi-asserted-by":"crossref","DOI":"10.1097\/MD.0000000000021176","article-title":"The usefulness of maximum standardized uptake value at the delayed phase of Tc-99m sestamibi single-photon emission computed tomography\/computed tomography for identification of parathyroid adenoma and hyperplasia","volume":"99","author":"Suh","year":"2020","journal-title":"Medicine (Baltimore)"},{"issue":"7","key":"2026090305471488900_luag225-B14","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1001\/archotol.132.7.779","article-title":"Technetium Tc 99m sestamibi sensitivity in oxyphil cell-dominant parathyroid adenomas","volume":"132","author":"Bleier","year":"2006","journal-title":"Arch Otolaryngol Head Neck Surg"},{"issue":"3","key":"2026090305471488900_luag225-B15","doi-asserted-by":"crossref","first-page":"567","DOI":"10.1097\/00005537-200303000-00032","article-title":"Preoperative parathyroid localization: correlating false-negative technetium 99m sestamibi scans with parathyroid disease","volume":"113","author":"Westreich","year":"2003","journal-title":"Laryngoscope"},{"issue":"7","key":"2026090305471488900_luag225-B16","doi-asserted-by":"crossref","first-page":"1482","DOI":"10.1002\/1097-0142(19850401)55:7<1482::AID-CNCR2820550711>3.0.CO;2-L","article-title":"Parathyroid carcinoma of the oxyphil cell type: a report of two cases, light and electron microscopic study","volume":"55","author":"Obara","year":"1985","journal-title":"Cancer"}],"container-title":["JCEM Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jcemcr\/article-pdf\/4\/10\/luag225\/70937405\/luag225.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jcemcr\/article-pdf\/4\/10\/luag225\/70937405\/luag225.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T09:47:24Z","timestamp":1788428844000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jcemcr\/article\/doi\/10.1210\/jcemcr\/luag225\/8780968"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,3]]},"references-count":16,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2026,9,3]]}},"URL":"https:\/\/doi.org\/10.1210\/jcemcr\/luag225","relation":{},"ISSN":["2755-1520"],"issn-type":[{"value":"2755-1520","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,10]]},"published":{"date-parts":[[2026,9,3]]},"article-number":"luag225"}}