Diagnosis of peritoneal carcinomatosis: transgastric versus transrectal EUS-guided FNA or percutaneous paracentesis

To the Editor: We read with interest the article by Schmulewitz et al1Schmulewitz N. Singh P. Safa M. et al.Diagnosis of peritoneal carcinomatosis by EUS-guided FNA.Gastrointest Endosc. 2007; 66: 825-826Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar on the diagnosis of peritoneal carcinomatosis with transgastric EUS-guided FNA. In their article, imaging studies revealed a large pancreatic mass invading to adjacent organs accompanied by marked ascites and many peritoneal implants. With transgastric EUS-guided FNA performed on the mass, ascites, and one peritoneal implant, malignant cells were revealed in all specimens. Because of the presence of marked ascites, we believe that percutaneous paracentesis or transrectal EUS-guided FNA should have been performed for the diagnosis of peritoneal carcinomatosis. In patients with abdominal malignancy, the detection of ascites predicts peritoneal carcinomatosis, which can impact patient management.2Matsushita M. Hajiro K. Takakuwa H. et al.Transvaginal versus transrectal ultrasonography in the diagnosis of peritoneal carcinomatosis.Am J Gastroenterol. 2000; 95: 1381Crossref PubMed Scopus (5) Google Scholar, 3Chu K.M. Kwok K.F. Law S. et al.A prospective evaluation of catheter probe EUS for the detection of ascites in patients with gastric cancer.Gastrointest Endosc. 2004; 59: 471-474Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar, 4Lee Y.T. Ng E.K.W. Hung L.C.T. et al.Accuracy of endoscopic ultrasonography in diagnosing ascites and predicting peritoneal metastases in gastric cancer patients.Gut. 2005; 54: 1541-1545Crossref PubMed Scopus (89) Google Scholar, 5Kaushik N. Khalid A. Brody D. et al.EUS-guided paracentesis for the diagnosis of malignant ascites.Gastrointest Endosc. 2006; 64: 908-913Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar, 6Dewitt J. Leblanc J. McHenry L. et al.Endoscopic ultrasound-guided fine-needle aspiration of ascites.Clin Gastroenterol Hepatol. 2007; 5: 609-615Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar, 7Nguyen P.T. Chang J. EUS in the detection of ascites and EUS-guided paracentesis.Gastrointest Endosc. 2001; 54: 336-339Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar Traditionally, percutaneous paracentesis has been a simple method for the diagnosis of peritoneal carcinomatosis in patients with apparent ascites.4Lee Y.T. Ng E.K.W. Hung L.C.T. et al.Accuracy of endoscopic ultrasonography in diagnosing ascites and predicting peritoneal metastases in gastric cancer patients.Gut. 2005; 54: 1541-1545Crossref PubMed Scopus (89) Google Scholar The large volume of ascites obtained by percutaneous paracentesis results in a high sensitivity rate for malignant cells.7Nguyen P.T. Chang J. EUS in the detection of ascites and EUS-guided paracentesis.Gastrointest Endosc. 2001; 54: 336-339Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar Recently, EUS-guided FNA has been an effective alternative for identifying malignant ascites.5Kaushik N. Khalid A. Brody D. et al.EUS-guided paracentesis for the diagnosis of malignant ascites.Gastrointest Endosc. 2006; 64: 908-913Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar, 6Dewitt J. Leblanc J. McHenry L. et al.Endoscopic ultrasound-guided fine-needle aspiration of ascites.Clin Gastroenterol Hepatol. 2007; 5: 609-615Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar, 7Nguyen P.T. Chang J. EUS in the detection of ascites and EUS-guided paracentesis.Gastrointest Endosc. 2001; 54: 336-339Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar The volume of ascites obtained by EUS-guided FNA is small, and this may explain a lower accuracy rate as compared with that of percutaneous aspiration.7Nguyen P.T. Chang J. EUS in the detection of ascites and EUS-guided paracentesis.Gastrointest Endosc. 2001; 54: 336-339Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar We therefore believe that percutaneous paracentesis should have been primarily performed in the patient of Schmulewitz et al1Schmulewitz N. Singh P. Safa M. et al.Diagnosis of peritoneal carcinomatosis by EUS-guided FNA.Gastrointest Endosc. 2007; 66: 825-826Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar who presented with marked ascites. EUS can identify small amounts of ascites missed by other imaging studies such as US and CT.2Matsushita M. Hajiro K. Takakuwa H. et al.Transvaginal versus transrectal ultrasonography in the diagnosis of peritoneal carcinomatosis.Am J Gastroenterol. 2000; 95: 1381Crossref PubMed Scopus (5) Google Scholar, 3Chu K.M. Kwok K.F. Law S. et al.A prospective evaluation of catheter probe EUS for the detection of ascites in patients with gastric cancer.Gastrointest Endosc. 2004; 59: 471-474Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar, 4Lee Y.T. Ng E.K.W. Hung L.C.T. et al.Accuracy of endoscopic ultrasonography in diagnosing ascites and predicting peritoneal metastases in gastric cancer patients.Gut. 2005; 54: 1541-1545Crossref PubMed Scopus (89) Google Scholar, 5Kaushik N. Khalid A. Brody D. et al.EUS-guided paracentesis for the diagnosis of malignant ascites.Gastrointest Endosc. 2006; 64: 908-913Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar, 6Dewitt J. Leblanc J. McHenry L. et al.Endoscopic ultrasound-guided fine-needle aspiration of ascites.Clin Gastroenterol Hepatol. 2007; 5: 609-615Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar, 7Nguyen P.T. Chang J. EUS in the detection of ascites and EUS-guided paracentesis.Gastrointest Endosc. 2001; 54: 336-339Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar Because transgastric EUS can only detect ascites in the upper abdomen, ascites in the lower abdomen or Douglas' pouch may be missed.4Lee Y.T. Ng E.K.W. Hung L.C.T. et al.Accuracy of endoscopic ultrasonography in diagnosing ascites and predicting peritoneal metastases in gastric cancer patients.Gut. 2005; 54: 1541-1545Crossref PubMed Scopus (89) Google Scholar We previously described a transrectal EUS technique that is a more sensitive and simpler way to detect small amounts of ascites.2Matsushita M. Hajiro K. Takakuwa H. et al.Transvaginal versus transrectal ultrasonography in the diagnosis of peritoneal carcinomatosis.Am J Gastroenterol. 2000; 95: 1381Crossref PubMed Scopus (5) Google Scholar The transrectal method is a noninvasive and convenient approach to the pelvic cavity, and seems to be clinically more useful than the transgastric method.