An Unusual Presentation of Parathyroid and Micro Papillary Thyroid Carcinoma

Abstract

Abstract Background: Parathyroid carcinoma is a rare endocrine malignancy, that usually presents with parathyroid hormone elevations five to ten times higher than normal. It is rarely diagnosed in cases with a normal or mildly elevated PTH. Clinical Case: 68 yo female with history of Hypertension, Spontaneous Vocal Cord Paralysis, Multinodular Goiter, Breast cancer s/p right radical mastectomy/chemotherapy, and Osteoporosis who presented to outpatient Endocrine clinic for hypercalcemia. Medications include Coreg 12.5 mg BID. Patient was asymptomatic. Labs showed BUN 21 mg/dL [8 mg/dL - 27 mg/dL], Creatinine 0.82 mg/dL [0.57 mg/dL - 1 mg/dL], eGFR 74 ml/min/1.73 m2 [nl>59 ml/min/1.73 m2], Calcium 10.8 mg/dL [8.7 mg/dL - 10.3 mg/dL], Phosphorus 3 mg/dL [3 mg/dL - 4.3 mg/dL], Magnesium 2.2 mg/dL [1.6 mg/dL - 2.3 mg/dL], PTH 77 pg/mL [15 pg/mL - 65 pg/mL], Albumin 4.2 g/dL [3.8 g/dL - 4.8 g/dL], Vitamin D 1,25 Dihydroxy 47.2 pg/mL [19.9 pg/mL - 79.3 pg/mL], Vitamin D 25-OH 18.2 ng/mL Low [30 ng/mL - 100 ng/mL], TSH 1.599 uIU/mL (.450-5.330 uIU/mL), Hgb 13.4 g /dL (12.0 -16.0 g/dL). Most recent FNA in 2019 of a dominant thyroid nodule was benign. Bone Density Scan June 2020 showed a T score of -3.4 in the lumbar spine and -3.1 in the left hip. Sestamibi Scan showed a right inferior parathyroid adenoma. Following ENT consultation, patient underwent surgical exploration. Pathology showed parathyroid tissue with extensive fibrosis, consistent with Parathyroid Carcinoma (1.8 x 1 x .7cm), probable positive margins, nodular growth pattern with individual nodules separated by fibrous bands, capsular invasion, focally, into adjacent adipose tissue invading through the thyroid capsule, positive for perineural invasion and PTH. Ki67 approximately six percent. Right thyroid lobe excision should a micro focus of papillary thyroid carcinoma (.2 x .2 cm), capsulated, negative margins, pT1a. Conclusion: This case demonstrated an unusual presentation of Parathyroid carcinoma causing a mild elevation of PTH level that in pathology after excision unexpectedly revealed a right parathyroid carcinoma along with micro papillary thyroid carcinoma.