The coexistence of hypercalcemia and hypoglycemia in a patient with a renal tumor and B cell lymphoma

SUMMARY Paraneoplastic syndromes are a heterogeneous group of malignant diseases caused by events which involve endocrine, immune and metabolic aspects and whose symptoms vary according to the substance produced and the primary tumor. Hypercalcemia is a frequent complication in cancer patients. Prognosis of cancer patients with hypercalcemia is usually poor. A factor called parathyroid hormone related peptide, whose actions are similar to those of the parathyroid hormone, is thought to be the most common cause of malignancy associated hypercalcemia. Non-islet hypoglycemic cell tumor consists of a rare syndrome characterized by the presence of a solid tumor and severe fasting hypoglycemia determined by an insulin-independent pathway. We report a case of a 59-year-old-man with a renal tumor and a T-cell rich large B cell lymphoma who was hospitalized due to severe hypercalcemia and hypoglycemia. The laboratory examination reported hypercalcemia with inhibited PTH and hypoglycemia with inhibited insulin secretion, arriving to the conclusion of tumoral peptide production. He received denosumab and corticoid therapy. The patient died one month later despite initial improvement after medical treatment. While a single paraneoplastic manifestation may be expected in most tumors, the coexistence of two or more of them is rare, except in hepatocellular carcinomas, and it has not yet been described in renal tumors.