A 56 year old lady presented with a short history of neuromuscular weakness. She was dehydrated but conscious, alert and oriented and without focal neurology. Her initial blood results revealed a corrected calcium 5.02 mmol/L, phosphate 1.49 mmol/L, alkaline phosphatase 152 iu/L, urea 31.8 mmol/L and creatinine 266 micromol/L.Intravenous rehydration with normal saline and 90 mg of pamidronate was given. She received 4 litres of normal saline daily and her renal functions normalised. However her calcium level remained elevated (nadir 3.17). A CT scan abdomen and pelvis revealed a 20 cm pelvic malignancy with para aortic nodes. There was no evidence of bony metastases. Her repeated PTH levels (intact PTH 184) were elevated 178202 ng/litre (N 1565). A sestamibi scan did not reveal any uptake in the neck. Despite aggressive treatment of her hypercalcemia, her calcium levels remained elevated and repeat dose of pamidronate was given. A para-aortic node biopsy and surgical surgery was planned. However, on the 20th Hospital day, she deteriorated quickly and passed away. Autopsy revealed a necrotic carcinoma of the ovary with nodal and liver metastases. The tumour was negative for neuroendocrine markers.
Discussion: Hypercalcemia with elevated parathormone suggests hyperparathyroidism. Severe refractory hypercalcemia is unusual in hyperparathyroidism. Her sestamibi scan showed no parathyroid uptake. Hypercalcemia in solid malignancy can be due to osteolytic secondaries, parathyrormone related peptide (PTHrp). In this setting, parathormone levels are suppressed. Malignancies can rarely secrete parathormone. Secretion of parathormone from neuroendocrine, pancreatic and lung malignancies has been reported. Ovarian malignancy with an abnormal promoter of the PTH gene has been reported.
Conclusion: This ovarian malignancy presented with severe refractory hypercalcemia and elevated parathormone level. Parathormone production by her malignancy is unusual but a possible mechanism for her refractory hypercalcemia.