SUN-504 Association of Primary Hyperparathyroidism and Humoral Hypercalcemia of Malignancy in a Patient with Metastatic Endocervical Adenocarcinoma

Background: Paraneoplastic hypercalcemia is serious and commonly seen in a variety of malignancies. However its occurrence in gynecological malignancies is rare. We present a case of severe hypercalcemia due to the a rare occurrence of both parathyroid hormone (PTH) mediated and PTH-related protein (PTHrP) mediated hypercalcemia. Clinical Case: A 56-year-old female with a history of endocervical adenocarcinoma stage IVb metastatic to the peritoneum, lung, and bone and CKD stage III presented to the emergency department with symptoms of generalized pain, nausea and lethargy. Patient was diagnosed with endocervical adenocarcinoma 4 months prior to presentation and was treated with 2 cycles of chemotherapy (carboplatin/paclitaxel). At the time of diagnosis her total calcium was elevated at 11.9 mg/dL [8.9-10.4 mg/dL], however she did not have any further evaluation or treatment of the hypercalcemia. On presentation to the emergency department, total calcium was elevated at 17.3 mg/dL [8.9-10.4 mg/dL], albumin 3.0 g/dL [3.8-5.3 g/dL], creatinine 1.6 mg/dL [0.6-1.2 mg/dL], eGFR 35.8 mL/min/1.73m(2), ionized calcium 2.85 [1.14-1.33], 25-hydroxy vitamin D 35 ng/mL [30-80 ng/mL], 1,25-dihydroxy vitamin D 24.8 pg/mL [19.9-79.3 pg/mL], PTH 401pg/mL [15-88 pg/mL] and PTH-related protein 65.3 pmol/L [0.0-3.4 pmol/L], Bone-specific alkaline phosphatase 58.1 U/L [14.2-42.7 U/L]. Patient was treated aggressively with intravenous fluids, calcitonin subcutaneously and pamidronate 60 mg intravenous infusion, given the depressed renal function. The total calcium level decreased to 10.9 mg/dL [8.9-10.4 mg/dL]. Nuclear medicine Tc-99m MDP whole body scan showed increased activity in the left proximal femur and left-sided pubic rami and questionable increased activity in the right iliac bone posteriorly and left anterior superior iliac spine. This was unchanged compared to a prior study done at the time of diagnosis. Immunohistochemical staining performed on the endocervical biopsy was negative for parathyroid hormone. Patient was discharged home with outpatient follow-up with oncology for zometa infusion however rapidly declined and passed away within 2 days. Conclusions: This is a rare case reporting concurrent PTH-dependent and PTH-related protein mediated pathways’ in a patient with advanced endocervical adenocarcinoma resulting is severe hypercalcemia. This case illustrates the importance of expanding differential diagnosis to consider disease states which require targeted therapy.