AbstractAn unusual finding of systemic calcinosis in a patient with a nonparathyroid malignant neoplasm stimulated us to do a clinicopathologic review of similar cases at our institution in the past seven years. Of 3,268 autopsies performed from 1968 to 1975, a total of 17 cases of calcinosis were found, 11 with solid tumors and 6 with hematopoietic neoplasms. Calcinosis was most prominent in the lung, kidney, heart, and stomach and was rarely discovered prior to death. Eighty‐two percent of the patients had hypercalcemia and 53% had associated bony metastatic disease. Corticosteroid or phosphate treatment for the hypercalcemia may have contributed to the tissue deposition of calcium. Significant hepatic, renal, metabolic, and pulmonary dysfunctions were also associated with this disorder. Thirty‐six percent of the patients had hypercalcemia without skeletal involvement; tumor‐produced para‐thormone‐like substances may be responsible for these calcium abnomalities. Calcinosis was a significant complication of neoplastic disease in these patients and contributed to morbidity and