OBJECTIVES:To pathologically clarify the macroscopic features of endoscopic ultrasound-guided fine needle aspiration/biopsy (EUS-FNA/B) specimens in representative pancreatic diseases and establish tissue-handling standards based on the macroscopic findings. METHODS:We gathered EUS-FNA/B specimens of cases at our institution with the final diagnoses of pancreatic ductal adenocarcinoma (PDAC, n = 172), neuroendocrine tumor (NET, n = 19), and chronic inflammatory lesion (CIL, n = 24) including autoimmune pancreatitis. We classified the specimens' macroscopic features in five categories (red strings, mixed-red-and-white strings, white cores, gray tissues, gelatinous tissues) and compared the specimens' features on cytological and histological slides. RESULTS:All five macroscopic categories were observed in variable combinations in the PDACs; red strings and white cores predominated in the NETs and CILs. White cores represented neoplastic (PDAC, NET) or lesion (CIL) tissues. Mixed-red-and-white strings were unique to PDACs and contained cancerous cells. Neoplastic cells were numerous in red strings in NETs but not the other groups. Gray and gelatinous tissues represented necrosis and mucin, respectively, and the former were almost exclusively observed in PDACs. Red strings, mixed-red-and-white strings, and white cores were suitable for histological examination, whereas gray and gelatinous tissues were suitable for cytological examination. The white cores, mixed-red-and-white strings, and gelatinous tissues may be composed of non-neoplastic tissues such as contaminated gastrointestinal epithelium. In seven PDACs, although white cores were obtained, a histological diagnosis was not established. CONCLUSIONS:Macroscopic evaluations of EUS-FNA/B can enable the identification of specimen components and a possible diagnosis. They also contribute to the selection of the optimal tissue-handling methods.

Several vaccines have been developed for coronavirus disease 2019 (COVID-19) and are used worldwide. Here we report a case of severe acute hepatitis induced by COVID-19 vaccination. A 54-year-old woman received two doses of the Pfizer-BioNTech COVID-19 mRNA vaccine and an additional dose of the Moderna COVID-19 mRNA vaccine. Seven days after the third dose, she noticed fatigue, appetite loss and dark urine. Laboratory tests were consistent with severe liver injury and jaundice. Anti-smooth muscle antibody and HLA-DR4 were positive; thus, we suspected that she had autoimmune hepatitis (AIH). Intravenous methylprednisolone followed by oral prednisolone were administered. Because remission was not achieved, we performed percutaneous liver biopsy. Histologically, pan-lobular inflammation with moderate infiltration of lymphocytes and macrophages, interface hepatitis, and rosette formation were present. We regarded these findings as confirmation of the diagnosis of AIH. As she had not responded to corticosteroids, we added azathioprine. Liver biochemistry tests gradually improved, and prednisolone could be tapered without relapse of AIH. Dozens of cases of AIH after COVID-19 vaccination have been reported. Corticosteroids were effective in most cases, but some patients have died from liver failure after vaccination. This case illustrates the efficacy of azathioprine for steroid-refractory AIH induced by COVID-19 vaccination.

The extent of tumor spread influences on the clinical outcome, and which determine T stage of colorectal cancer. However, pathologic discrimination between pT3 and pT4a in the eighth edition of the American Joint Committee on Cancer (AJCC)-TNM stage is subjective, and more objective discrimination method for deeply invasive advanced colon cancer is mandatory for standardized patient management. Peritoneal elastic laminal invasion (ELI) detected using elastic staining may increase the objective discrimination of deeply invasive advanced colon cancer. In this study, we constructed ELI study group to investigate feasibility, objectivity, and prognostic utility of ELI. Furthermore, pT classification using ELI was investigated based on these data. At first, concordance study investigated objectivity using 60 pT3 and pT4a colon cancers. Simultaneously, a multi-institutional retrospective study was performed to assess ELI's prognostic utility in 1202 colon cancer cases from 6 institutions. In the concordance study, objectivity, represented by κ, was higher in the ELI assessment than in pT classification. In the multi-institutional retrospective study, elastic staining revealed that ELI was a strong prognostic factor. The clinical outcome of pT3 cases with ELI was significantly and consistently worse than that of those without ELI. pT classification into pT3 without ELI, pT3 with ELI, and pT4a was an independent prognostic factor. In this study, we revealed that ELI is an objective method for discriminating deeply invasive advanced colon cancer. Based on its feasibility, objectivity, and prognostic utility, ELI can subdivide pT3 lesions into pT3a (without ELI) and pT3b (with ELI).

症例は40歳の女性で，2か月持続する下腹部痛の増悪を主訴に当院を受診した．血液検査や尿検査で特記異常所見はなく，妊娠反応も陰性であった．CTおよびMRIで大網由来と考えられる7 cm大の単房性囊胞性腫瘤を認め，その他症状の原因となりうる器質的異常は認めなかった．症状の原因と判断し腹腔鏡下に摘出術を行った．術中所見で腫瘍は大網と連続し，骨盤内臓器との連続性は認めなかった．病理組織学検査では7 cm大の単房性囊胞性病変で，囊胞壁は一層の線毛上皮に被覆されていた．免疫染色結果ではPAX8に陽性を示し，卵巣の漿液性囊胞腺腫と相同の病変と考えられた．術後，症状は消失した．漿液性囊胞腺腫は典型的には卵巣に発生するが，後腹膜腔以外では後縦隔に発生した報告がまれながらある．大網発生の報告はないが，卵管や卵管采の上皮が異所性に迷入し発生したと推測された．本症例のように有症状となった場合，手術適応と考えられた．

Ono, Takafumi MD, PhD; Koyama, Takashi MD, PhD; Notohara, Kenji MD, PhD; Sakata, Yuki MD; Akaike, Yoko MD, PhD; Itakura, Junya MD, PhD; Yamano, Takafumi MD; Hayase, Momoko MD; Ishida, Tadashi MD, PhD Author Information

Background Salivary duct carcinoma (SDC) is a high-grade salivary malignancy that frequently occurs as the carcinomatous component of carcinoma ex pleomorphic adenoma. We herein examined the clinical factors affecting outcomes in a large cohort of SDC. Methods We selected 304 SDC cases and investigated clinical characteristics and the factors affecting outcomes. Results The median age of the cases examined was 68 years, the most common primary site was the parotid gland (238 cases), and there was a male predominance (M/F = 5:1). Outcomes were significantly worse when the primary tumor site was the minor salivary glands (SG) than when it was the major SG. Outcomes were also significantly worse in pN(+) cases (161 cases) than in pN0 cases, particularly those with a metastatic lymph node number >= 11. The cumulative incidence of relapse and distant metastases was significantly higher in stage IV cases than in stage 0-III cases. Conclusions The absolute number of lymph node metastases, higher stages, and the minor SG as the primary tumor site were identified as factors affecting the outcome of SDC.

We report here a case of a 62-year-old woman with multiple gastric enterochromaffin-like cell neuroendocrine tumor caused by hypergastrinemia due to parietal cell dysfunction that was successfully treated with somatostatin analogue. Esophagogastroduodenoscopy revealed several G1 neuroendocrine tumors, 10 mm in diameter, in the body of the stomach. No evidence of autoimmune gastritis, Helicobacter pylori infection, neuroendocrine neoplasia type 1, or Zollinger–Ellison syndrome was identified. The pattern of immunohistochemical staining of the background gastric mucosa was suggestive of parietal cell dysfunction. She was treated with long-acting release octreotide acetate. Complete response was confirmed after 9 months and was maintained for 22 months.

The utility of gastric biopsy for diagnosing immunoglobulin (Ig)G4-related gastrointestinal disease (IgG4-GID) remains unclear. Bottom-heavy plasmacytosis (BHP) is a distinct feature of IgG4-GID. To clarify the feasibility of using gastric biopsies to diagnose BHP in IgG4-GID, we analyzed the histological features and immunostaining of gastric biopsy specimens from 31 known IgG4-related disease (IgG4-RD) patients and we assessed the presence of BHP in 1696 consecutive routine gastric biopsies. Cases with both >10 IgG4-positive plasma cells per high-power field and an IgG4/IgG-positive ratio >40% were defined as IgG4-high. Ten of the 31 IgG4-RD patients were concluded to have IgG4-GID, in which IgG4-positive plasma cells were notably detected at the deeper part of the mucosa. Six cases displayed BHP whereas the remaining four cases showed transmural infiltration with concomitant Helicobacter pylori-associated gastritis. In addition to BHP, we identified two unique histologic features for IgG4-GID: plasmacytic aggregation in the muscularis mucosae and permeative plasmacytic infiltration between fundic glands in the non-atrophic mucosa. Six of the routine cases (0.35%) displayed BHP, including a case with IgG4-RD. IgG4-GID can be suspected by the presence of gastric biopsy specimens with characteristic histological features. Such cases are recommended to undergo further examinations to determine whether IgG4-RD is present.

Histopathological diagnosis of pancreatic ductal adenocarcinoma (PDAC) on endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) specimens has become the mainstay of preoperative pathological diagnosis. However, on EUS-FNB specimens, accurate histopathological evaluation is difficult due to low specimen volume with isolated cancer cells and high contamination of blood, inflammatory and digestive tract cells. In this study, we performed annotations for training sets by expert pancreatic pathologists and trained a deep learning model to assess PDAC on EUS-FNB of the pancreas in histopathological whole-slide images. We obtained a high receiver operator curve area under the curve of 0.984, accuracy of 0.9417, sensitivity of 0.9302 and specificity of 0.9706. Our model was able to accurately detect difficult cases of isolated and low volume cancer cells. If adopted as a supportive system in routine diagnosis of pancreatic EUS-FNB specimens, our model has the potential to aid pathologists diagnose difficult cases.

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Background and Aims: Cold snare polypectomy (CSP) of small colorectal polyps is widely used. However, the technique is still troubled by insufficient resection depth, which may prevent precise pathologic evaluation. In this study, we investigated whether submucosal injection of saline solution helps to achieve deeper resection in CSP. Methods: The study was a single-center, prospective, randomized trial. Patients with small (3- to 10-mm diameter) nonpedunculated adenomatous or sessile serrated colorectal polyps were randomly allocated to either conventional CSP (C-CSP) or CSP with submucosal injection (CSP-SI). Primary outcome was the rate of complete muscularis mucosae (MM) resection, defined by the proportion of MM under the tumor more than 80% of the tumor's horizontal dimension. Secondary outcomes were the rates of negative lateral and vertical margins, fragmentation of resected specimens, conversion to hot snare mucosal resection, intraprocedural bleeding, delayed bleeding, and perforation. Results: Two hundred fourteen patients were randomly assigned to the CSP-SI (n = 107) or C-CSP (n = 107) group. The rate of complete MM resection was 43.9% in the CSP-SI group and 53.3% in the C-CSP group, a statistically insignificant difference. The rates of negative lateral margin and vertical margin (42.3% and 56.7%, respectively) in the CSP-SI group were significantly lower than those (58% and 76%) in the C-CSP group (P = .03 and P = .006, respectively). There was no polypectomy-related major bleeding or perforation. Conclusions: Saline solution injection into the submucosa did not improve the resection depth of CSP of small colorectal polyps, and the method resulted in lower rates of negative lateral and vertical margins of resected lesions.

A 76-year-old male with lower-limb weakness was admitted to our hospital where thrombocytopenia and anemia were noticed. CT showed massive splenomegaly and multiple nodules inside the spleen. Bone marrow examination showed an increase of macrophages with large cytoplasm. Suspected of splenic lymphoma, the patient underwent splenectomy. Spleen specimens were histologically analyzed and suggested the probability of Gaucher's disease (GD). Leukocyte glucocerebrosidase (GBA) enzyme activity had decreased to 1.25 nmol/mg, and mutation analysis of GBA revealed two missense variants, p.D448H (D409H), p.L483P (L444P), which confirmed the diagnosis of type I GD. Fourteen months after splenectomy, he developed right buttock pain, and pelvic magnetic resonance imaging showed a fragile right pubic and pelvic fracture. We initiated injection of imiglucerase as enzyme replacement therapy (ERT) and administered bisphosphonate. His symptoms gradually improved without surgical treatment. In addition, thrombocytopenia and anemia also improved, and angiotensin-converting enzyme levels decreased. Type I GD should be considered a differential diagnosis of giant splenomegaly and thrombocytopenia, even in the elderly. ERT or substrate reduction therapy should be administrated to GD patients, while paying attention to the development of bone lesions.

Background Management of diminutive pharyngeal neoplasms is controversial. Thus, we conducted a single-center, prospective pilot study to investigate the efficacy and safety of endoscopic excision with cold forceps biopsy (CFB) of these lesions. Patients and Methods Thirty-nine lesions endoscopically diagnosed with narrow-band imaging as pharyngeal neoplasms of 3 mm or smaller were excised with CFB using jumbo biopsy forceps (cap diameter 2.8 mm, jaw volume 12.4 mm(3)). The primary outcome was endoscopically determined local remnant/recurrence rate 3 months after CFB. The secondary outcomes were histopathologically determined local remnant/recurrence rate; risk factors associated with the endoscopic remnant/recurrence; and incidence of intraoperative or delayed bleeding and other adverse events. Results Histological diagnosis of the 39 CFB-excised lesions were: 11 high-grade dysplasia (28.2%), 22 low-grade dysplasia (56.4%), two basal cell hyperplasia (5.1%) and four atypical squamous epithelium (10.3%).Twenty-seven patients (30 lesions) underwent follow-up endoscopy 3 months after CFB; the endoscopic and pathological local remnant/recurrence rate was 20% (6/30; 95% confidence interval (CI), 7.7-36.6%) and 16.7% (5/30; 95% CI, 5.6-34.7%), respectively. Location of the lesion in the hypopharynx was a significant risk factor associated with the endoscopic local remnant/recurrence (P = 0.049). No significant adverse events occurred. Conclusions Cold forceps biopsy with jumbo biopsy forceps appears to be a safe and effective technique for excising diminutive pharyngeal neoplasms. Although small, the excised lesions may have a remarkably high frequency of high-grade dysplasia. (Clinical trial registration number: UMIN000037980).