A Retrospective Study: Confocal Laser Endomicroscopy For Diagnosis Pathological Classification Of Gastric Cancer In Vivo

BACKGROUND AND AIMTraditional endoscopy can only observe superficial mucosal shape of digestive tract, so biopsy is needed to make final diagnosis for gastrointestinal diseases. Endoscopic biopsy examination has complex protocol and wastes much time. In some people, biopsy may cause bleeding and some other complications. Confocal laser endomicroscopy (CLE) is the newest advance of endoscopy, which integrates confacal laser microscopy into the end of traditional endoscopy. CLE can carry out confocal microscopic examination of the mucosal layer during ongoing endoscopy and get immediate in vivo subsurface histological images of gastrointestinal mucosa. The CLE image has a magnification of 1000 and similar with the mucosal cross-section pathology, so CLE is also named virtual biopsy. Several study have showed that CLE has excellent value for diagnosing gastric cancer, but there is no systemic study for CLE in the pathologic classification of gastric cancer. The main aims of this study are to describe the CLE image feature of different pathologic classifications of gastric cancer and to evaluate the diagnostic value of CLE in pathologic classifications of gastric cancer retrospectively.PATIENTS AND METHODSThirty-six patients underwent confocal laser endomicroscopy examination and diagnosed with gastric cancer with biopsy, while 10 patients with normal mucosa underwent CLE examination. The confocal images obtained from the normal mucosa and cancerous lesions were interpreted by a CLE doctor, who did not know the conventional endoscopic findings and histological findings of the patient. In confocal images, gastric cancer is classified into two types: differentiated type and undifferentiated type. The histological finding are regarded as gold standard, and we evaluate the sensitivity,specialty and accuracy of CLE for gastric cancer and two pathological classifications of gastric cancer.RESULTS1. Fifty-three sites were checked by CLE in 46 patients and 9263 confocal images were obtained. Among all images, 86.1 percents were good and moderate. Twenty-two patients were diagnosed with differentiated gastric cancer by histological results, and 14 patients with undifferentiated gastric cancer.2. In confocal images, gastric cancer has two pathological types: differentiated type and undifferentiated type. In the confocal images of differentiated gastric cancer, normal gastric pits disappeared and were replaced by irregular atypical glands. The number of microvessels increased, meanwhile the microvessels had various caliber and irregular shape. In the confocal images of undifferentiated gastric cancer, there were diffusely atypical cells instead of normal gastric pits. The number of microvessels decreased , meanwhile the shape of microvessels was irregular and like short branch.3. The sensitivity,specialty and accuracy of CLE for gastric cancer were 97.2%,100% and 98.1%. With regard to pathological classification of gastric cancer, the sensitivity,specialty and accuracy of CLE for differentiated gastric cancer were 81.8 %,93.5% and 88.7%. For undifferentiated gastric cancer, the sensitivity,specialty and accuracy were 85.7%,92.3% and 90.5%.CONCLUTIONSAccording to the change of glandular and microvascular architecture, confocal laser endomicroscopy can classify gastric cancer into differentiated type and undifferentiated type. CLE has potential value for diagnosis of differentiated and . undifferentiated gastric cancer, compared with histopathological findings. Confocal laser endomicroscopy is a new method for in vivo diagnosis of pathological classification of gastric cancer during routine endoscopic procedures.