Ovarian non-small cell neuroendocrine carcinoma with paraneoplastic parathyroid hormone-related hypercalcemia

Ovarian tumors associated with hypercalcemia due to ectopic secretion of parathyroid hormone (PTH) are extremely rare. A 33-year-old woman presented with a pelvic mass and profound hypercalcemia accompanied by an elevated serum level of PTH. Laparotomy demonstrated a left ovarian tumor that on histological examination was a neuroendocrine carcinoma of non-small cell type admixed with a component of endometrioid adenocarcinoma. After left salpingo-oophorectomy, the serum calcium and PTH levels normalized. The cells of the neuroendocrine carcinoma were positive for neuron-specific enolase, synaptophysin, chromogranin A, and PTH. Hypercalcemia and elevated serum PTH levels recurred during tumor relapse, and the patient died of disease 6 months postoperatively. This is the eleventh case of neuroendocrine carcinoma of non-small cell type associated with surface epithelial neoplasm of the ovary, and the first such tumor to be associated with hypercalcemia.