Non-Hodgkin's lymphoma associated with hypercalcemia and increased activity of serum angiotensin-converting enzyme

We describe two patients with diffuse non-Hodgkin's lymphoma, hypercalcemia, and increased activity of serum angiotensin-converting enzyme. A mechanism similar to that operative in sarcoidosis is speculated to have caused the hypercalcemia. A lymphokine elaborated by the malignant lymphoma may cause activated macrophages to produce 1,25-dihydroxyvitamin D3.