Abstract
A familial cancer aggregation comprising sarcomas, brain tumors, leukemias, and carcinomas of breast, larynx, lung, adrenal cortex, and other sites has been studied from a pathologic—genetic standpoint. Based upon sibships segregating for cancer, the genetic segregation parameter is estimated to be 45.6 ± 11% which is compatible with that expected for a rare deleterious autosomal gene showing complete dominance. Pathologic review of 16 tumors by bright field microscopy revealed variable occurrences of intranuclear cytoplasmic invaginations, intranucleolar bodies, and acidophilic intracytoplasmic inclusions in eight lesions. Two tumors showed both intranuclear cytoplasmic invaginations and intranucleolar inclusions. Morphological findings coupled with the observed pattern and distribution of cancer in the subject kindred suggest that the cancer‐prone genotype interacts with one or more exogenous factors in causing this familial tumor association.