What types of early gastric cancer are indicated for endoscopic ultrasonography staging of invasion depth?

AIM To clarify the diagnostic efficacy and limitations of endoscopic ultrasonography(EUS) and the characteristics of early gastric cancers(EGCs) that are indications for EUS-based assessment of cancer invasion depth.METHODS We retrospectively investigated the cases of 153 EGC patients who underwent conventional endoscopy(CE) and EUS(20 MHz) before treatment.RESULTS We found that 13.7% were "inconclusive" cases with low-quality EUS images, including all nine of the cases with protruded(0-I)-type EGCs. There was no significant difference in the diagnostic accuracybetween CE and EUS. Two significant independent risk factors for misdiagnosis by EUS were identified-ulcer scarring [UL(+); odds ratio(OR) = 4.49, P = 0.003] and non-indication criteria for endoscopic resection(ER)(OR = 3.02, P = 0.03). In the subgroup analysis, 23.1% of the differentiated-type cancers exhibiting SM massive invasion(SM2) invasion(submucosal invasion ≥ 500 μm) by CE were correctly diagnosed by EUS, and 23.1% of the undifferentiated-type EGCs meeting the expanded-indication criteria for ER were correctly diagnosed by EUS.CONCLUSION There is no need to perform EUS for UL(+) EGCs or 0-I-type EGCs, but EUS may enhance the pretreatment staging of differentiated-type EGCs with SM2 invasion without UL or undifferentiated-type EGCs revealed by CE as meeting the expanded-indication criteria for ER.

Prospective postsurgical capsule endoscopy in patients with Crohn's disease

AIM: To clarify the usefulness of postsurgical capsule endoscopy(CE) in the diagnosis of recurrent small bowel lesions of Crohn's disease(CD). METHODS: This prospective study included 19 patients who underwent ileocolectomy or partial ileal resection for CD. CE was performed 2-3 wk after surgery to check for the presence/absence and severity of lesions remaining in the small bowel, and for any recurrence at the anastomosed area. CE was repeated 6-8 mo after surgery and the findings were compared with those obtained shortly after surgery. The Lewis score (LS) was used to evaluate any inflammatory changes of the small bowel. RESULTS: One patient was excluded from analysis because of insufficient endoscopy data at the initial CE. The total LS shortly after surgery was 428.3 on average(median, 174; range, 8-4264), and was ≥ 135(active stage) in 78%(14 of 18) of the patients. When the remaining unresected small bowel was divided into 3 equal portions according to the transition time(proximal, middle, and distal tertiles), the mean LS was 286.6, 83.0, and 146.7, respectively, without any significant difference. Ulcerous lesions in the anastomosed area were observed in 83% of all patients. In 38% of the 13 patients who could undergo CE again after 6-8 mo, the total LS was higher by ≥ 100 than that recorded shortly after surgery, thus indicating a diagnosis of endoscopic progressive recurrence. CONCLUSION: Our pilot study suggests that CE can be used to objectively evaluate the postoperative recurrence of small bowel lesions after surgery for CD.

Histological diagnosis of gastric submucosal tumors: A pilot study of endoscopic ultrasonography-guided fine-needle aspiration biopsy vs mucosal cutting biopsy

AIM: To compare the usefulness of endoscopic ultrasonography-guided fine-needle aspiration biopsy(EUS-FNAB) without cytology and mucosal cutting biopsy(MCB) in the histological diagnosis of gastric submucosal tumor(SMT).METHODS: We prospectively compared the diagnostic yield, feasibility, and safety of EUS-FNAB and those of MCB based on endoscopic submucosal dissection. The cases of 20 consecutive patients with gastric SMT ≥1 cm in diameter. who underwent both EUS-FNAB and MCB were investigated.RESULTS: The histological diagnoses were gastrointestinal stromal tumors(n = 7), leiomyoma(n =6), schwannoma(n = 2), aberrant pancreas(n = 2), and one case each of glomus tumor, metastatic hepatocellular carcinoma, and no-diagnosis. The tumors' mean size was 23.6 mm. Histological diagnosis was made in 65.0% of the EUS-FNABs and 60.0% of the MCBs, a nonsignificant difference. There were no significant differences in the diagnostic yield concerning the tumor location or tumor size between the two methods. However, diagnostic specimens were significantly more frequently obtained in lesions with intraluminal growth than in those with extraluminal growth by the MCB method(P = 0.01). All four SMTs with extraluminal growth were diagnosed only by EUSFNAB(P = 0.03). No complications were found in either method.CONCLUSION: MCB may be chosen as an alternative diagnostic modality in tumors showing the intraluminal growth pattern regardless of tumor size, whereas EUSFNAB should be performed for SMTs with extraluminal growth.

Diagnosis of small intramucosal signet ring cell carcinoma of the stomach by non-magnifying narrow-band imaging: A pilot study

AIM: To examine the efficacy of non-magnifying narrow-band imaging(NM-NBI) imaging for small signet ring cell carcinoma(SRC).METHODS: We retrospectively analyzed 14 consecutive small intramucosal SRCs that had been treated with endoscopic submucosal dissection(ESD) and 14 randomly selected whitish gastric ulcer scars(control). The strength and shape of the SRCs and whitish scars by NM-NBI and white-light imaging(WLI) were assessed with Image J(NIH, Bethesda).RESULTS: NM-NBI findings of SRC showed a clearly isolated whitish area amid the brown color of the surrounding normal mucosa. The NBI index, which indicates the potency of NBI for visualizing SRC, was significantly higher than the WLI index(P = 0.001), indicating SRC was more clearly identified by NM-NBI. Although the NBI index was not significantly different between SRCs and controls, the circle(C)-index, as an index of circularity of tumor shape, was significantly higher in SRCs(P = 0.001). According to the receiveroperating characteristic analysis, the resulting cut-off value of the circularity index(C-index) for SRC was 0.60(85.7% sensitivity, 85.7% specificity). Thus a lesion with a C-index ≥ 0.6 was significantly more likely to be an SRC than a gastric ulcer scar(OR = 36.0; 95%CI: 4.33-299.09; P = 0.0009).CONCLUSION: Small isolated whitish round area by NM-NBI endoscopy is a useful finding of SRCs which is the indication for ESD.