The interval between the diagnosis of malignancy and the development of effusions, with reference to the role of cytologic diagnosis.

An analysis was made of the time lapse between the diagnosis of malignancy and the development of an effusion in relation to the sex and age of the patients and the site of the primary malignancy. The total number of patients studied was 254; of these, 171 patients had a pleural and 83 patients a peritoneal effusion. In the total group, sex distribution was two men to three women: about equal in the pleural effusion group and about two men to nine women in the ascites group, with the latter ratio reflecting the large number of primary malignant processes in the breast and ovaries. The average age at the time of the effusion, whether it was located in the pleural or in the peritoneal cavity, was about 55 years. This figure was roughly 60 years for men and 51 years for women. The nine-year average age difference between sexes can be explained by the size of the four largest groups of different primary malignant localizations and their sex distribution. The interval between the discovery of the primary malignancy and the first fluid sample was longer for patients with a pleural effusion (average of 77.0 weeks) than for patients with ascites (average of 54.5 weeks). The longest interval was seen in the breast carcinoma group, with the shortest interval in lung carcinoma patients. The interval was significantly longer for women, being 111.9 weeks for pleural effusions and 57.9 weeks for ascites (average for both sites of 88.7 weeks). In 30.7% of the patients, the primary malignancy was discovered at the same time or later than the effusion; in patients with lung cancer, a strikingly higher percentage of 53.0% was found. In this respect, the cytologic diagnosis of effusions is of great importance not only for the detection and proper identification of a malignant process but also as an indicator of the life expectancy of a patient.