CYTOLOGY OF FLUIDS FROM PLEURAL, PERITONEAL AND PERICARDIAL CAVITIES IN CHILDREN - A COMPREHENSIVE SURVEY

We reviewed all cytologic specimens of pleural, peritoneal and pericar dial fluids examined in our laboratory from patients aged 0-17 years d uring a 12-year period. A total of 103 Specimens were studied: 45 pleu ral, 54 peritoneal and 4 pericardial. Twenty-two of the 103 specimens were peritoneal washes. Eleven of the 81 (14%) serous effusion specime ns contained tumor cells: 8 lymphomas, 1. leukemia, 1 abdominal desmop lastic small round cell tumor and 1 Wilms' tumor. Two false-positive d iagnoses were made in patients presenting with ascites with an unknown cause. Both cases were complicated by the presence of atypical mononu clear cells and illustrate a potential pitfall in the evaluation of pe diatric serous effusions. We conclude: (1) Almost all pediatric effusi ons Rue benign. (2) Malignant pediatric effusions are usually caused b y neoplasms of the small cell type, mostly lym-phoreticular. (3) The m ajor diagnostic difficulty in interpreting pediatric effusion cytology is in distinguishing neoplasms of the small cell type from mononuclea r inflammatory cells. (4) The usefulness of peritoneal washings in ped iatric patients is similar to that in adults.