title: An unusual case of recurrent hyperparathyroidism and papillary thyroid cancer.
abstract: OBJECTIVE
  To report an unusual occurrence of recurrent hyperparathyroidism due to papillary thyroid carcinoma.
  
  
  METHODS
  We describe the clinical history, physical examination findings, laboratory values, imaging findings, and pathologic findings of a woman who developed recurrent hyperparathyroidism 13 years after successful parathyroidectomy.
  
  
  RESULTS
  A 59-year-old woman presented to our clinic with recurrent primary hyperparathyroidism. In 1994, she presented with nephrolithiasis and underwent resection of a right superior parathyroid adenoma that resulted in clinical and biochemical cure. Her clinical course had been followed at periodic intervals, and she had been symptom-free and normocalcemic. In 2007, she again developed nephrolithiasis and was documented to have recurrent hyperparathyroidism. Imaging studies suggested a parathyroid adenoma near the right inferior pole of the thyroid. The patient had reoperative neck exploration. No obvious parathyroid adenoma was found and a right thyroid lobectomy was performed, which resulted in normalization of intraoperative intact parathyroid hormone levels, and the incision was closed. Final pathology demonstrated no parathyroid adenoma, but instead, a 1-cm papillary thyroid carcinoma that stained positive for parathyroid hormone. More than 6 months after surgery, she remains clinically and biochemically cured.
  
  
  CONCLUSIONS
  Recurrent hyperparathyroidism occurs secondary to multiple causes. This case demonstrates the challenge a surgeon faces in managing recurrent disease and highlights a rare phenomenon of papillary thyroid cancer causing recurrent hyperparathyroidism.
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Shane Y
authors.initials: SY
authors.lastname: Morita
authors.forename: Noel A
authors.initials: NA
authors.lastname: Brownlee
authors.forename: Alan P B
authors.initials: AP
authors.lastname: Dackiw
authors.forename: William H
authors.initials: WH
authors.lastname: Westra
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Clark
authors.forename: Martha A
authors.initials: MA
authors.lastname: Zeiger
mesh_terms: D002291:Carcinoma, Papillary / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology; D007150:Immunohistochemistry; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology