SAT200 A Case Of Ectopic Parathyroid Adenoma With Significantly Improved Renal Function And Insulin Resistance After Parathyroidectomy

Disclosure: S. Lee: None. H. Ppyun: None. Y. Shin: None. N. Hong: None. H. Choi: None. Background: It is challenging to treat patients with clinically suspected hyperparathyroidism not localized by conventional imaging methods. Here, we present clinical evidence that supports new modalities for localization and ultimate surgical removal of a lesion. Clinical case: An increase in calcium and PTH was found incidentally in a 59 YO male patient who was followed up for type 2 diabetes mellitus and DMCKD (stage 4). Initial lab tests were as follows: Ca, 11.6 mg/dL (8.2∼10.8); P 3.3 mg/dL (2.5∼4.7); PTH 184.1 pg/mL (18.5∼88.0); BUN/Cr 4.84/3.38 mg/dL (8∼22/0.5∼1.2); protein in random urine 1020.1 mg/dL (6∼20). Suspected of primary hyperparathyroidism, ultrasonography and sestamibi scan were performed, but no parathyroid lesions were found. While only palliative treatment was maintained, parathyroid venous sampling (PVS) (1) and 18-fluorocholine PET/CT (2) were performed, and a mass within 2 cm in diameter was found in the left mediastinum, which was then removed by thoracoscopic robotic excision. Diffuse weak staining for PTH in the removed lesion confirmed that it was a tissue derived from the parathyroid gland. After surgery, lab tests were improved as follows: Ca 9.1 mg/dL; P 3.6 mg/dL; PTH 69 pg/mL. When 90 units of insulin were administered before surgery, HbA1c was 8.7%, but even after insulin was reduced to 15 units post-surgery HbA1c decreased to 7.2%, significantly reducing the need for insulin treatment. Proteinuria also decreased to 123.1 mg/dL, indicating that renal function was also improved. Conclusion: This case highlights the merit of newly introduced 18-fluorocholine PET/CT and PVS to find a parathyroid lesion that could not be found by conventional imaging methods. It is recommended to consider active surgical treatment for hyperparathyroidism, mainly to prevent deterioration of bone health and kidney function. In addition, since concurrent diabetes can be improved by parathyroidectomy (3), this case shows the need to more actively find lesions and take a causal approach. Reference: (1) Yamada T, Ikuno M, Shinjo Y, Hiroishi A, Matsushita S, Morimoto T, et al. Selective venous sampling for primary hyperparathyroidism: how to perform an examination and interpret the results with reference to thyroid vein anatomy. Jpn. J. Radiol. 2017;35:409-16. (2) Marina Orevi 1, Nanette Freedman, Eyal Mishani, Moshe Bocher, Orit Jacobson, Yodphat Krausz. Localization of parathyroid adenoma by ¹¹C-choline PET/CT: preliminary results. Clin. Nucl. Med. 2014;39:1033-8 (3) Noghani SN, Milani N, Afkhamizadeh M, Kabiri M, Bonakdaran S, Vazifeh-Mostaan L, et al. Assessment of insulin resistance in patients with primary hyperparathyroidism before and after Parathyroidectomy. Endocrinol Diab Metab. 2021;4:e00294. Presentation: Saturday, June 17, 2023