Yoshiyasu Kitagawa

Magnified endoscopic observation of early colorectal cancer by linked color imaging with crystal violet staining (with video)

BACKGROUND AND AIMS Many reports have shown the usefulness of magnification endoscopy with crystal violet (CV) staining for delineating the pit pattern in the diagnosis of colorectal carcinoma. However, the diagnostic accuracy of this method is not adequate for assessing the depth of invasion of early stage cancers. The novel technology of linked color imaging (LCI) combined with CV staining is expected to improve the accuracy of determining the depth of invasion. METHODS We studied 3 patients with early stage colorectal cancer who were referred to our hospital. After CV spraying, high-magnification endoscopy was conducted by using the LCI mode. Efficacy of this modality was evaluated by comparing the preoperative diagnostic endoscopic images with posttreatment histopathologic findings. RESULTS In 2 cases of rectal cancer, although conventional endoscopic examination could not exclude the possibility of submucosal cancer, use of the LCI mode with CV staining confirmed mucosal cancer. Eventually, EMR was conducted and achieved curative resection. In 1 case of sigmoid colon cancer, both conventional and CV magnification endoscopy suggested submucosal cancer. However, mucosal cancer was diagnosed by the novel method, and EMR achieved curative resection. CONCLUSIONS LCI high-magnification endoscopy combined with CV staining provides images close to histopathologic findings and is expected to improve the accuracy of endoscopic diagnosis of the depth of invasion for early stage colorectal cancer.

Enhanced detection of lymphovascular invasion in small rectal neuroendocrine tumors using D2‐40 and Elastica van Gieson immunohistochemical analysis

Rectal neuroendocrine tumor (RNET) lymphovascular invasion (LVI) is regarded as an important predictor of nodal metastasis after endoscopic resection (ER). However, little is known about the frequency of immunohistochemical detection of LVI in RNETs. This study was performed to establish the actual detection of LVI rate in RNETs ≤10 mm and to evaluate associated clinical outcomes. We retrospectively reviewed the records for 98 consecutive patients treated by ER with a total of 102 RNETs ≤10 mm. Tissue sections were labeled with hematoxylin–eosin (HE) stain, the D2‐40 monoclonal antibody to evaluate lymphatic invasion, and Elastica van Gieson (EVG) stain to detect venous invasion. LVI detection rate by HE versus immunohistochemical analysis was compared. Follow‐up findings and clinical outcomes were also evaluated for 91 patients who were followed for ≥12 months. Lymphatic and venous invasion were detected using HE staining alone in 6.9% and 3.9% of patients, respectively, whereas they were detected using D2‐40 and EVG staining in 20.6% and 47.1% of the patients, respectively. Thus, the LVI detection frequency using D2‐40 and EVG staining (56.9%) was significantly higher than with HE (8.8%). Two out of seven patients who required additional surgery had regional lymph node metastases. However, among the 84 patients who were followed up without surgery, no distant metastases or recurrences were detected. Compared with HE staining, immunohistochemical analysis significantly increased the frequency of LVI detection in RNETs ≤10 mm. However, the clinical impact of LVIs detected using immunohistochemical analysis remains unclear. Clarification of the actual role of LVI using immunohistochemical analysis requires a patient long‐term follow‐up and outcomes.

Safety and efficacy of endoscopic submucosal dissection using IT knife nano with clip traction method for early esophageal squamous cell carcinoma

BackgroundAlthough endoscopic submucosal dissection (ESD) is an accepted and established treatment for early esophageal squamous cell carcinoma (EESCC), it is technically difficult, time consuming, and less safe than endoscopic mucosal resection. To perform ESD safely and more efficiently, we proposed a new technique of esophageal ESD using an IT knife nano with the clip traction method. This study aimed to evaluate the efficacy and safety of ESD using this new technique.MethodsWe retrospectively reviewed all consecutive cases of esophageal ESD performed using an IT knife nano with the clip traction method at our hospital between March 2013 and January 2017. Therapeutic efficacy and safety were also assessed.ResultsA total of 103 patients underwent esophageal ESD using the IT knife nano with the clip traction method. In all cases, we performed en bloc resection. Complete resection was achieved in 100 cases (97.1%). The median operating time was 40 (range 13–230) min. No cases of perforation or delayed bleeding occurred. Although two cases (2.0%) of mediastinal emphysema occurred without visible perforation at endoscopy, all were successfully managed conservatively.ConclusionsThe new technique of esophageal ESD using the IT knife nano with the clip traction method appears to be feasible, effective, and safe for EESCC treatment.

Magnified endoscopic observation of small depressed gastric lesions using linked color imaging with indigo carmine dye

BACKGROUND AND STUDY AIMS Magnifying linked color imaging with indigo carmine dye (M-Chromo-LCI) enables sterically enhanced and color image-magnified observation of the superficial gastric mucosa. This study investigated the usefulness of M-Chromo-LCI for the differential diagnosis of gastric lesions. PATIENTS AND METHODS 100 consecutive small depressed lesions were examined with conventional white-light imaging (C-WLI), magnifying blue-laser imaging (M-BLI), and M-Chromo-LCI. Endoscopic images were reviewed by three experts and three non-experts. Diagnostic accuracy and interobserver agreement were compared among the modalities. RESULTS For experts, M-BLI showed a significantly higher diagnostic accuracy than C-WLI (82.7 % vs. 67.0 %; P < 0.001). The diagnostic accuracy of M-Chromo-LCI was not different from M-BLI (87.7 % vs. 82.7 %; P = 0.31). For non-experts, M-BLI showed a significantly higher diagnostic accuracy than C-WLI (69.3 % vs. 52.3 %; P < 0.001). M-Chromo-LCI additionally showed a significantly higher diagnostic accuracy than M-BLI (79.7 % vs. 69.3 %; P = 0.005). M-Chromo-LCI had the highest interobserver agreement for each group. CONCLUSIONS M-Chromo-LCI is expected to become a useful modality for the accurate diagnosis of gastric lesions.

Usefulness of close observation with non-magnified blue laser imaging for determining cold polypectomy indications

Abstract Purpose: To examine the usefulness of non-magnified close observation with blue laser imaging (BLI) using a colonoscope with close observation capability in determining indications for cold polypectomy. Methods: We conducted an image evaluation study on 100 consecutive colorectal lesions of 10 mm or less which were observed endoscopically without magnification using BLI mode prior to treatment. Two experts and two non-experts reviewed the images using the Japan NBI expert team (JNET) classification and the diagnostic accuracy was analyzed. Results: The final pathological diagnoses of the 100 lesions were hyperplastic/sessile serrated polyp (HP/SSP), low grade dysplasia (LGD), high grade dysplasia (HGD) and deep submucosal invasive cancer (dSM), respectively, in 12, 79, 9 and 0 lesions. When JNET classification type 1 corresponds to HP/SSP; 2A to LGD; 2B to HGD; and 3 to dSM; the overall diagnostic accuracy was 84.3%. Accuracy was 90.5% for experts and 78.0% for non-experts. High confidence rate was 67.5% for experts and 48.0% for non-experts. In diagnostic accuracy for HGD, the sensitivity, specificity, PPV and NPV were, respectively, 77.8%, 98.9%, 87.5% and 97.8% for experts; and 66.6%, 92.3%, 46.2% and 96.6% for non-experts. Conclusions: The diagnostic accuracy of unmagnified close observation with BLI using a colonoscope with close observation capability is similar to that reported for magnifying endoscopy and is useful in predicting the histological diagnosis of colorectal polyps of 10 mm or less although the effectiveness may be limited for non-experts. This modality is a potentially useful tool in deciding indications for cold polypectomy.

Feasibility of endoscopic submucosal dissection for cecal lesions

Abstract Background: The treatment results of endoscopic submucosal dissection (ESD) for colorectal lesions have improved markedly, but some lesions remain difficult to treat. Hence the cecum is considered a technically challenging site for ESD. We examined the feasibility of ESD for cecal lesions. Methods: Among a total of 708 colorectal ESD performed in our hospital between March 2006 and December 2016, 549 procedures performed after April 2012 were studied, at a time when the techniques of ESD had stabilized and the procedure was covered by health insurance in Japan. Among 549 cases, 61 were cecal lesions and 488 were noncecal lesions. The treatment outcomes were analyzed. Results: For cecal lesions, the en bloc resection rate was 95.1%, R0 resection rate was 91.8%, perforation rate was 0%, delayed bleeding rate was 6.6%, median diameter of resected specimen was 32 mm (16–65 mm), median time of the procedure was 44 minutes (8–140 min). The corresponding results for noncecal lesions were 97.3%, 95.5%, 0.4%, 2.7%, 30 mm (10–109 mm), and 37 min (7–225 min). No significant differences were observed and the good treatment results were seen. When the outcomes were analyzed for cecal sites considered to be particularly challenging; proximity to appendiceal orifice, the ileocecal valve, and the bottom of cecum, the treatment results were not inferior to other sites. Conclusions: ESD is safe and effective even for cecal lesions considered challenging to treat. ESD is feasible for cecal lesions.

Frequent Presence of Lymphovascular Invasion in Small Rectal Neuroendocrine Tumors on Immunohistochemical Analysis

Rectal neuroendocrine tumors (RNETs) have become common in recent years and are good candidates for endoscopic resection (ER). To achieve clear resection margins, more advanced techniques such as endoscopic submucosal dissection, endoscopic submucosal resection with a ligation device, and cap-assisted endoscopic mucosal resection are available for ER. After ER, lymphovascular invasion (LVI) is regarded as an important predictor of nodal metastasis. Previous studies have shown that small RNETs with LVI were uncommon (0-8.3%). However, using immunohistochemical analysis, a recent study revealed the frequent occurrence of LVI in small RNETs in a systematic manner (46.7%). There is a possibility that the actual detection rate of LVI in small RNETs is not always evaluated accurately because of the limited detection sensitivity of conventional hematoxylin-eosin staining. In addition, the correlation between LVI detected using immunohistochemical analysis and the development of metastasis remains unclear. Further prospective studies are required to clarify the role of LVI detected using immunohistochemical analysis.

A case report of prostate cancer metastasis to the stomach resembling undifferentiated-type early gastric cancer

BackgroundOccurrence of metastatic cancer to the stomach is rare, particularly in patients with prostate cancer. Gastric metastasis generally presents as a solitary and submucosal lesion with a central depression.Case presentationWe describe a case of gastric metastasis arising from prostate cancer, which is almost indistinguishable from the undifferentiated-type gastric cancer. A definitive diagnosis was not made until endoscopic resection. On performing both conventional and magnifying endoscopies, the lesion appeared to be slightly depressed and discolored area and it could not be distinguished from undifferentiated early gastric cancer. Biopsy from the lesion was negative for immunohistochemical staining of prostate-specific antigen, a sensitive and specific marker for prostate cancer. Thus, false initial diagnosis of an early primary gastric cancer was made and endoscopic submucosal dissection was performed. Pathological findings from the resected specimen aroused suspicion of a metastatic lesion. Consequently, immunostaining was performed. The lesion was positive for prostate-specific acid phosphatase and negative for prostate-specific antigen, cytokeratin 7, and cytokeratin 20. Accordingly, the final diagnosis was a metastatic gastric lesion originating from prostate cancer.ConclusionIn this patient, the definitive diagnosis as a metastatic lesion was difficult due to its unusual endoscopic appearance and the negative stain for prostate-specific antigen. We postulate that both of these are consequences of hormonal therapy against prostate cancer.