Background: Metastatic adenocarcinomas in effusions are frequently observed. Cytologic diagnosis of adenocarcinoma is often precise; unfortunately, the classification of the primary site is not possible in a great number of cases. The scope of this study was to report the frequency of adenocarcinomas in effusions according to the primary site.
Material: We studied 2317 sequential cases: 1146 pleural effusions (943 women and 203 men), 1168 ascitic (727 women and 441 men), and 3 pericardial (2 women and 1 men).
Method: Retrospective analysis of the records of the patients and correlations of the data of clinical follow up and morphological findings.
Results: The primary sites more frequently seen in pleural cavity were: breast (N = 586--51.1%), lung (N = 185--16.1%: 102 men and 83 women), and ovary (N = 124--10.8%); in ascites: stomach (N = 473--40.5%: 300 men and 173 women), ovary (N = 306--26.2%) and breast (N = 83--7.1%). Regarding only the samples of malignant effusions we observed 555 in pleural cavity: breast (N = 288--51.9%), lung (N = 92, 16.6%: 45 men and 47 women) and ovary (N = 54, 9.7%). In ascites we reported: ovary (N = 205--37.9%), stomach (N = 202--37.3%: 119 men and 83 women) and breast (N = 31--6.8%). In 47 pleural effusions (8.5%) and 37 ascites (6.8%), the original site of the neoplasia remained undetermined.
Conclusion: The knowledge of the relative frequencies, associated with clinical information, can be helpful in the selection of further investigation for the metastatic adenocarcinomas.