Not just weight loss

Abstract

Renal cancer (RC) – associated increased calcium is rather frequent among cases of kidney neoplasia; it may be the first sign of presentation that allows the detection of the malignancy; typically representing a poor prognostic factor. Weight loss is part of the panel underling hypercalcemia - related signs, but also of the malignancy – associated phenotype. We aim to introduce a male case who was admitted for a clinical picture (including weight loss) correlated with alarming high calcium levels; the biochemistry anomaly was actually a paraneoplastic syndrome due to RC. When admitted as emergency, the assays revealed hypercalcemia of 16.9 mg/dl (normal levels between 8.4 and 10.2 mg/dl) with low PTH (Parathormone) and high CrossLaps as bone turnover marker of resorption. Intravenous contrast computed tomography showed a large left retroperitoneal tumor (involving the kidney and adrenal gland) with iodophil pattern, and post-contrast heterogeneous structure of 8.06/11.09 cm (axial), 10.58/12.16 cm (coronal-reconstruction), 9.12/10.59 cm (sagittal - reconstruction), also associating a mixt structure and micro-calcifications as well as hypodense areas. Whole body bone scintigram did not show metastasis. The calcium levels were controlled under subcutaneous denosumab 60 mg in addition to IV fluids replacement; then the patient was referred to nephrectomy; postoperative confirmation confirmed a clear cell renal cell carcinoma (T4N1Mx). A normalization of calcium and PTH levels was found immediately after surgery. Unintentional weight loss might become a valuable tool in order to assess a routine biochemistry panel that will detect hypercalcemia. Low PTH represents the next step in order to further look for a tumor. Symptomatic control of hypercalcemia in addition to targeted approach of originating tumor are essential to improve the outcome.