Diaphragmatic smears are not of additional benefit in the detection of peritoneal spread in gynecological cancers

Peritoneal biopsies (PB) and peritoneal washing (PW) are routine measures in abdominal staging of gynecological malignancies and are used particularly for the assessment of occult microscopic tumor spread to the peritoneal surface including the diaphragm. Cytological diaphragmatic smears (DS) have been suggested as a supplemental tool; however, they are not routinely taken and their usefulness is still unclear. The present study retrospectively evaluated whether DS provide an additional benefit over PB and PW for the detection of peritoneal malignancies in patients with gynecological cancer. The data from patients who underwent laparotomy for suspected gynecological cancer and had DS and either PB, PW or ascites were reviewed. Sensitivity and specificity, and the number upstaged patients were determined. A total of 43 patients were excluded due to benign diagnosis (those with negative DS or PW) and 2 out of the remaining had 2 carcinomas simultaneously. Among these 41 malignancies, DS were positive in 12, PW in 18 and PB in 19 cases. No case was DS-positive while negative for both PB and PW. Four cases were missed when only PB and 5 when only PW was performed. Notably, no case of peritoneal disease was identified solely on positive DS, indicating that all 23 positive cases (presence of occult peritoneal disease in 56.1%) were identified by PB and PW together (100% sensitivity; 62% specificity). In addition, none of the cases was upstaged solely on positive DS results. Taken together, these data demonstrated that DS do not present an additional benefit to PW and PB in the detection of peritoneal gynecological disease.