Endocrine Abstracts

Introduction: While hypercalcemia is extensively studied in cancer patients, the occurrence of hypocalcemia is not as commonly reported. The unique aspect of this case lies in severe hypocalcemia against the background of a malignant tumor of the cervix, a condition often associated with hypercalcemia.

Case report: A 66-year-old patient, diabetic for 13 years with insulin therapy, is being treated for poorly differentiated squamous cell carcinoma of the cervix for the past 4 years. She underwent an extensive hysterectomy, lymph node dissection, followed by radiotherapy with chemotherapy. Five days after the last chemotherapy session, the patient experienced paresthesias and tingling in the face and upper and lower limbs, along with muscle cramps and a tetanic episodes. Faced with this clinical presentation, she was referred to our department. Upon clinical examination, the patient was stable, and Chvostek’s sign was positive. The investigation revealed corrected hypocalcemia at 68 mg/l with a phosphorus level of 40 mg/l and a Vitamin D deficiency of 11.6 ng/ml. The PTH level was normal at 39.2 pg/ml. Renal and hepatic function tests were normal. The patient was placed on calcium and vitamin D supplementation, leading to significant improvement.

Discussion: While hypercalcemia is a well-recognized paraneoplastic syndrome, hypocalcemia remains a rare event in neoplastic diseases. Several factors may contribute to the development of hypocalcemia in cancer patients, including Chemotherapeutic agents, commonly used in cancer treatment, may contribute to hypocalcemia, as well as bisphosphonates frequently employed for bone metastases. Proton pump inhibitors, widely used in cancer patients, may decrease calcium absorption directly or through hypomagnesemia. Tumor lysis syndrome, common in hematological malignancies, can also occur in solid tumors, leading to acute renal failure and metabolic alterations, including hypocalcemia. Osteoblastic bone metastases can cause hypocalcemia through the avid capture of calcium, known as "hungry bone syndrome." Other causes include radiotherapy, infections, renal failure, and malnutrition.

Conclusion: Understanding the multifactorial nature of hypocalcemia development is crucial for appropriate diagnosis and management in cancer patients.