Primary multifocal lymphoma of bone presenting as hypercalcemic crisis: report of a rare manifestation of extranodal lymphoma.

Primary non-Hodgkin's lymphoma of bone is uncommon and usually manifests clinically as localized bone pain. Here we report a woman who presented with hypercalcemic crisis and extensive investigation revealed a primary multifocal lymphoma of bone. The course of the disease was very aggressive and despite intensive supportive care and urgent chemotherapy the patient died within 1 month. Since her blood PTH and calcitriol levels were suppressed and her parathyroid-hormone-related peptide (PTHrp) was mildly elevated, we believe that release of cytokines combined with PTHrp, as well as extensive osteolytic lesions, were the causes of the hypercalcemia. This is an unusual presenting symptom of lymphomas and to the best of our knowledge severe symptomatic hypercalcemia and crisis has never been reported in primary lymphoma of bone before.