Hypercalcemia preferentially occurs in unusual forms of childhood non-Hodgkin's lymphoma, rhabdomyosarcoma, and Wilms' tumor. A study of 11 cases.

Unusual clinical, radiologic, or histologic findings were found in 11 of 17 cases of hypercalcemia associated with childhood tumors. Four children had undifferentiated lymphoblastic lymphoma with extensive bone involvement, but no visceral or neurologic involvement. At diagnosis, four adolescents with rhabdomyosarcoma had numerous metastases, particularly in the breasts and bone marrow. Three infants had renal tumor without bone metastases. Histologically, their tumors differed from classical nephroblastoma and resembled the malignant rhabdoid tumors of the kidney. These findings allow individualization of three distinct groups of tumors with unusual features which may suggest the presence of hypercalcemia. These tumors appear to have a poor prognosis since all patients but one died of their malignancy.