Double Parathyroid Carcinoma

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 199-237-Disorders of Parathyroid Hormone & Calcium Homeostasis
Translational
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-209
Katrina Acedo Abadilla*1, Celeste Ong Ramos2, Jeffrey Domino3 and Michael L Villa4
1Sinai Hosp of Baltimore, Baltimore, MD, 2St. Luke's Medical Center, Quezon City, Philippines, 3St. Luke's Medical Center, Philippines, 4St Lukes Medical Center, San Juan, Philippines
ABSTRACT

Background:

Parathyroid carcinoma is an uncommon endocrine malignancy.  A double primary and/or an intrathyroidal parathyroid carcinoma are yet more exceedingly rare. 

Clinical Case:

We report a case of hypercalcemia secondary to primary hyperparathyroidism from double parathyroid carcinoma in a 54-year-old Filipino lady.  She has a history of benign colloid nodular goiter status post subtotal thyroidectomy 30 years ago and was on thyroid hormone replacement therapy since then.  She was diagnosed 3 years ago with staghorn nephrolithiases, with normal calcium levels.  This year, she was noted to have hypercalcemia.  She had elevated ionized calcium (1.39 mmol/l) and intact PTH (276 pg/ml).  Thyroid ultrasound revealed left lobe solid nodules and right lobe complex nodule.  Parathyroid 99mTc-(sestaMIBI) scintigraphy showed an avid focus in the left thyroid bed likely due to hyperactive parathyroid adenoma, malignancy cannot be ruled out, and a scintigraphic evidence of complex thyroid nodule in the right lobe.  Bone (DEXA) densitometry revealed osteopenia.  Surgery was performed using quick intraoperative intact PTH assay (QPTH).  The intact PTH (54 pg/ml) and ionized calcium (1.14 mmol/l) levels fell to normal range after removal of both tumors.  Histopathological examination revealed a multinodular colloid adenomatous goiter on the right thyroid lobe, a parathyroid carcinoma within the left thyroid lobe with a tumor size of 2 cm in its widest diameter, and a left superior parathyroid carcinoma measuring 1.1 and 2.3 cm in its widest diameter with lymphovascular invasion and tumor infiltration of surgical margins. There was no other evidence of distant metastasis or part of MEN Syndrome 1.  To the best of our knowledge, this is only the sixth case report of double parathyroid carcinoma confirmed histologically.

Conclusion:

Preoperative and intraoperative diagnosis of parathyroid carcinoma is challenging, especially if localized within the thyroid gland [1-2]. Current techniques such as thyroid ultrasound and sestaMIBI scanning may fail to differentiate an adenoma versus a malignancy [3]. Fine needle aspiration [1,4] and intraoperative biopsies [1,5] are also of limited value in diagnosing parathyroid carcinoma, and in fact should be avoided to prevent needle track seeding[6,7].  Primary en bloc resection of the tumor, avoiding capsule rupture and spillage of the tumor cells, is the procedure of choice [6,7].  Other treatment modalities such as chemotherapy and radiotherapy have been largely ineffective in the treatment of parathyroid carcinoma [6,8].  Our case indicates that QPTH is the useful tool for detecting double parathyroid tumors even if one is located in the thyroid gland [1,5,9].

1. Krulijac I, Pavic I, Matesa N, et al. Intrathyroid parathyroid carcinoma with intrathyroidal metastasis to the contralateral lobe: source of diagnostic and treatment pitfalls. Japn J Clin Onc 2011;41(9):1142–1146. 2. Abboud B, Sleilaty G, Ayoub S, et al. Intrathyroid parathyroid adenoma in primary hyperparathyroidism: can it be predicted preoperatively? World J Surg 2007;31:817 – 823. 3. Foppiani L, Del Monte P, Sartini G, et al. Intrathyroidal parathyroid carcinoma as cause of hypercalcemia and pitfall of localization techniques: clinical and biologic features. Endo Prac 2007;13(2):176–181. 4. Tseleni-Balafouta S, Gakiopoulou H, Kavantzas N, et al. A source of diagnostic pitfalls in FNA of thyroid. Cancer 2007;111:130–136. 5. Givi B, Shah JP. Parathyroid carcinoma. Clin Oncol R Coll Radiol 2010;22:498–507. 6. Sahasranam P, Tran M, Mohamed H, et al. Multinodular parathyroid carcinoma: a case report and brief review. South Med Assoc 2007;100(8):841–844. 7.Obara T, Okamoto T, Kanbe M, et al. Functioning parathyroid carcinoma clinicopathlogic features and rational treatment. Semin Surg Oncol 1997;13:134–141. 8. Shane E. Parathyroid carcinoma. J Clin Endocrinol Metab 2001;86:485–493. 9. Kameyama K, Takami H. Endoc J 2003;50(4):477–479

Nothing to Disclose: KAA, COR, JD, MLV

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