Endocrine Abstracts

Introduction: Calcitriol-mediated hypercalcemia is one of the most common paraneoplastic syndromes associated with lymphoma.

Aim: Evaluate clinical and biochemical manifestations as well on the management of hypercalcemia in patients with lymphoma.

Materials and methods: Prospective analysis of patients with lymphoma who developed hypercalcemia during September-2011 and January-2016.

Results: Two hundred and six patients with high-grade lymphoma were reported, 189 with diffuse large B-cell lymphoma (DLBCL) and 17 with adult Tcell leukemia/lymphoma (ATLL). Hypercalcemia was documented in 15 patients (incidence of 7.28%) of whom 13 were DLBCL and two ATLL, mostly with stage IV disease. Median age was 60 years (range 36–85); 53.3% women. Up to one-third of the cases, symptoms of hypercalcemia were reported, predominantly those involving neurological manifestations (somnolence, delirium) and polyuria. Mean calcium was 3.1 mmol/l±0.4 (range 2.6–4.2) and phosphatemia 1.1 mmol/l±0.4 (range 0.7–1.5). Median concentration of serum calcidiol and calcitriol was 51.1 nmol/l±24.6 (range 14–95, reference value above 50) and 160 pmol/l±99 (range 6–342, reference value 39–193), respectively. Calcitriol was determined in 86.6% patients, only a quarter presented levels above de limit range. Serum PTH was suppressed in 13/15 patients. PTH-rp was determined in 13/15 cases; elevated serum levels were found only in one patient with supressed PTH. Eighty percent patients were treated with chemotherapy; the rest of them could not begin treatment due to impaired performance status. Slightly more than half of them received specific treatment for hypercalcemia previous to chemotherapy (66.6% hydration, 40% furosemide, 40% corticosteroids, 20% bisphosphonates). Calcium was normalized in 93.3% of patients, in relation to response to chemotherapy, with a mean value of 2.3 mmol/l±0.18, 18±15 days after starting treatment.

Conclusion: Hypercalcemia associated with lymphoma is a relatively common disorder. In our series, the classic pattern mediated by calcitriol was observed only in 25% of the patients; most of them had multifactorial pathogenesis.