[Unknown significance monoclonal gammopathy (USMG) and primary hyperparathyroidism (PH) on diferential diagnosis of hypercalcemia: case report].

The monoclonal gammopathy of undetermined significance (USMG) is a pre-malignant rare asymptomatic disease, defined by a concentration of immunoglobulin in serum monoclonal more than 3 g/dL and a proportion of plasma cells in bone marrow more than 10% in the absence of lytic bone lesions, anemia, hypercalcemia and renal failure related to monoclonal cell proliferation. Primary hyperparathyroidism (PH) is a relatively frequent disease, affecting approximately one in 1,000 individuals. Some studies suggest that the frequency of PH is increased in cancer, broadening the spectrum of etiology of hypercalcemia in these patients. We report here a case of a 63 years-old patient admitted for investigation of anemia, paresthesias, pain in the lower limbs and kidney failure. During investigation, there was hypercalcemia, serum monoclonal peak of IgA/lambda without criteria for multiple myeloma and with parathyroid adenoma. Patient was submitted to parathyroidectomy, which anatomicopathological revealed parathyroid adenoma. After surgery, levels of calcium and kidney function returned to normal.