Hypercalcaemia: a clue to Mycobacterium avium intracellulare infection in a patient with AIDS.

Hypercalcaemia is uncommon in HIV-infected patients and should suggest a different priority for differential diagnosis than would be considered in other settings. Although hypercalcaemia has long been associated with granulomatous diseases including tuberculosis, it has only recently been recognised that patients with illness due to Mycobacterium avium intracellulare (MAI) may develop it. We report a patient with AIDS in whom unexplained hypercalcaemia was the harbinger of clinically significant MAI infection. Patients with AIDS who develop hypercalcaemia should be closely evaluated for underlying MAI infection.