SAT-231 A Case of Small Cell Ovarian Cancer, Hypercalcemic Type, in Pregnancy

Introduction Hypercalcemia in pregnancy is uncommon. Immediate evaluation and management is key to manage hypercalcemia in pregnancy to prevent maternal and fetal complications. Some common causes include primary hyperparathyroidism, vitamin D toxicity, and hyperthyroidism. An uncommon cause of hypercalcemia in pregnancy is small cell ovarian cancer, hypercalcemic type (SCCOHT). Case 26 year old woman, presented to the emergency department at 22 weeks of gestation with complaints of generalized weakness, fatigue, increased thirst, constipation, and intermittent right lower quadrant abdominal pain for 2 weeks. Past medical history was significant for polycystic ovarian syndrome. Labs revealed elevated albumin-corrected calcium: 17.5 mg/dl (8.7-10.5 mg/dl), low serum phosphorus: 2.1 mg/dl (2.7-4.5 mg/dl), low 25-OH vitamin D: 13 ng/ml (30-96 ng/ml), 1,25-OH Vitamin D: 44 pg/ml (20-79 pg/ml), and elevated PTHrP: 14 pmol/L (<2 pmol/L). The intact PTH was 12 pg/ml (9-77 pg/ml). TSH < 0.010 uIU/ml (0.4-4.0 uIU/ml) and free T4: 1.91 ng/dl (0.71-1.51 ng/dl). TSI & TPO levels were low. CA 125 was elevated: 135 U/ml (0-30 U/ml). Patient received IV hydration, IV furosemide, calcitonin, and pamidronate at the time of admission for management of hypercalcemia. MRI revealed large right adnexal mass measuring 19 cm; mostly solid but with cystic components. She underwent exploratory laparotomy with salpingo-oophorectomy. On post-op day 1 albumin corrected calcium decreased to 11.3 mg/dl. Repeat PTHrP on post-op day 3 decreased to 0.5 pmol/L. Pathology was notable for SCCOHT. At 27 weeks gestation, patient went into spontaneous labor and delivered. Following the delivery, she was started on chemotherapy with etoposide/cisplatin. After completion of one cycle of chemotherapy, her albumin corrected calcium level was 10.3 mg/dl. She was able to tolerate her first cycle of chemotherapy well and was in stable condition at the time of discharge. Discussion This case demonstrates an uncommon cause of hypercalcemia in pregnancy. Although rare (1% of all ovarian tumors), SCCOHT is an aggressive tumor with poor prognosis. SCCOHT should be considered as a differential in a young woman presenting with severe hypercalcemia. Majority of patients with SCCOHT have hypercalcemia, primarily mediated through the production of PTHrP, however our patient also had measurable calcitriol level possibly contributing to hypercalcemia. References Münstedt K, Estel R, Dreyer T, Kurata A, Benz A. Small Cell Ovarian Carcinomas - Characterisation of Two Rare Tumor Entities.&nbsp;Geburtshilfe Frauenheilkd. 2013;73(7):698-704.