Using endoscopic ultrasonography (EUS), it is practicable to diagnose subepithelial lesions (SEL) with originating layer, echo level, and internal echo pattern etc. Lipoma, lymphangioma, and cyst have characteristic features; therefore, there is no need for endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA). Ectopic pancreas and glomus tumors, which originate from the third and fourth layers, are frequently seen in the antrum. However, ectopic pancreas located in the fundus or body is large and originates from the third and fourth layers (thickening of fourth layer). Each subepithelial lesion has characteristic findings. However, imaging differentiation of tumors originating from the fourth layer is very difficult, even if contrast echo is used. Therefore, EUS‐FNA should be done in these tumors, but the diagnostic yield for small lesions is not sufficient for clinical demands. Generally, those tumors, including small ones, should be first followed up in 6 months, then yearly follow up in cases of no significant change in size and features. When those tumors become larger than 1–2 cm, EUS‐FNA is recommended. Furthermore, unusual SEL and SEL with malignant findings such as nodular, heterogeneous, anechoic area, and ulceration indicate EUS‐FNA. Cap‐attached forward‐viewing echoendoscope is very helpful for EUS‐FNA of small SEL.

AIMTo evaluate the efficacy of doubling time (DT) of gastrointestinal submucosal tumors (GIST).METHODSFrom April 1987 through November 2012, a total of 323 patients were given a final histopathological diagnosis of GISTs on surgical resection or endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in Kitasato University East Hospital or Kitasato University Hospital. We studied 53 of these patients (34 with resected tumors and 19 with unresected tumors) whose tumors could be measured on EUS on at least two successive occasions. The histopathological diagnosis was GIST in 34 patients, leiomyoma in 5, schwannoma in 3, ectopic pancreas in 1, hamartoma in 1, cyst in 1, Brunner’s adenoma in 1, and spindle-cell tumor in 7. We retrospectively calculated the DT of GISTs on the basis of the time course of EUS findings to estimate the growth rate of such tumors.RESULTSThe DT was 17.2 mo for GIST, as compared with 231.2 mo for leiomyoma, 104.7 mo for schwannoma, 274.9 mo for ectopic pancreas, 61.2 mo for hamartoma, 49.0 mo for cyst, and 134.7 mo for Brunner’s adenoma. The GISTs were divided into risk classes on the basis of tumor diameters and mitotic figures (Fletcher’s classification). The classification was extremely low risk or low risk in 28 patients, intermediate risk in 3, and high risk in 3. DT of GIST according to risk was 24.0 mo for extremely low-risk plus low-risk GIST, 17.1 mo for intermediate-risk GIST, and 3.9 mo for high-risk GIST. DT of GIST was significantly shorter than that of leiomyoma plus schwannoma (P < 0.05), and DT of high-risk GIST was significantly shorter than that of extremely low-risk plus low-risk GIST (P < 0.05).CONCLUSIONFor GIST, a higher risk grade was associated with a significantly shorter DT. Small SMTs should initially be followed up within 6 mo after detection.

Aim Diagnosis of acute onset autoimmune hepatitis (A‐AIH) has been difficult in that patients may not have typical clinicopathological features of AIH. In our previous reports of severe and fulminant AIH, two‐thirds of them showed radiological heterogeneity: hepatic heterogeneous hypoattenuation on unenhanced computed tomography (CT) reflecting heterogeneous distribution of massive hepatic necrosis (severe centrilobular necrosis), which would be beneficial for the diagnosis. In the present study, we analyzed non‐severe A‐AIH patients with or without radiological heterogeneity and tried to find novel clinical features for supporting the early diagnosis. Methods Clinical, biochemical, immunological, radiological and histological features of 42 patients with non‐severe A‐AIH at community hospitals between 2010 and 2020 were analyzed. Results Of 42, 28 patients on whom CT scans were performed and who could be fully analyzed were enrolled. Five patients showed hepatic heterogeneous hypoattenuation on unenhanced CT. There was no significant difference in clinical, biochemical, immunological and histological features at diagnosis between the two groups according to the presence of radiological heterogeneity, although mean minimum prothrombin time activity during the course was lower in patients with heterogeneity without statistical significance (p = 0.080). All responded to treatment well and achieved initial remission within 3 months. Conclusions It is possible that patients with non‐severe A‐AIH show radiological heterogeneity reflecting centrilobular necrosis which is one of important diagnostic features of A‐AIH. Accordingly, radiological heterogeneity might be beneficial for the diagnosis of A‐AIH in combination with conventional clinicopathological features if it is detected in the absence of features suggestive of other liver diseases.

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