Metastatic Breast Carcinoma with Treatment- Resistant Hypocalcemia

Introduction: Hypocalcemia is a condition that can occur in malignant diseases due to tumor lysis syndrome or chemotherapy agents. Hypocalcemia due to hypoparathyroidism accompanying malignancy is very rare. We, in this report are sharing a case of metastatıc breast carcinoma with treatment -resistant hypocalcaemia. Case Report: A 37-year-old woman who was diagnosed and followed-up with panhypopituitarism and contractions throughout the body after a recent child delivery. On the basis of the positive chvostek and trausseu findings on the physical examination of the patient we did hypocalcemia work-up and found plasma calcium: 5.4mg/dl, phosphorus: 7.8mg/dl, albumin: 4g/dl, 25-OH vitamin D3: 18.7ng/ml and parathormone as <3pg/ml. Considering primary hypoparathyroidism, calcium carbonate and calcitriol treatments were applied. However, ca-gluconate infusion was initiated on the basis that calcium levels remained at 6.5mg/dl. In the cranial-pituitary MRI examination there were multiple millimetric nodular lesions of in cerebral and cerebellar hemispheres. PET/CT revealed a hypermetabolic area of malignant character in the lower quadrant of the left breast which can represent the primary tumor and multiple hipermetabolic areas in axial skeleton showing the most prominent activity in C2 and T6 vertebra. The biopsy result from the mass in the breast was reported as invasive lobular carcinoma and the patient was referred to the oncology department. Discussion: Hypoparathyroidism may develop due to surgery, autoimmune or destruction in the parathyroid gland. The cause of hypoparathyroidism, which further complicated the treatment of hypocalcemia in our patient, may be due to metastasis or to the possible autoimmune mechanisms or PTHrP. Osteoblastic metastasis and PTHrP may have been found at the same time, and this cycle may have shifted towards osteoblastic activity. We can’t find any association between breast cancer and autoimmune hypoparathyroidism in the literature. Conclusion: Although there are other reasons that complicate the clinical status in treatment-resistant hypocalcemia patients, it should be considered that there may be an underlying malignancy.