Immune Checkpoint Inhibitor-induced Pancreatitis with Pancreatic Enlargement Mimicking Autoimmune Pancreatitis: A Case Report and Review of the Literature.

A 61-year-old woman was administered 35 cycles of pembrolizumab for the treatment of recurrent endometrial cancer, achieving a complete response. She presented with asymptomatic pancreatic enlargement and elevated hepatobiliary enzymes, but amylase and lipase levels were within the normal ranges. Intrapancreatic bile duct stenosis due to pancreatic enlargement was present, mimicking autoimmune pancreatitis on computed tomography performed before the onset of clinical manifestations. A histological examination of a biopsy specimen showed lymphocyte and plasma cell infiltration with dense fibrosis in the stroma. The patient was successfully treated with oral prednisolone. There were no manifestations of recurrent pancreatitis after tapering the prednisolone dose.

The Ki67 index evaluation of pancreatic neuroendocrine tumors using 3D immunohistochemistry in small tissue specimens.

BACKGROUND: /Objectives: This study aimed to evaluate the usefulness of three-dimensional (3D) immunohistochemistry for the Ki67 index of small tissue specimens of pancreatic neuroendocrine tumor (PanNET). METHODS: Clinicopathological materials from 17 patients with PanNET who underwent surgical resection at Jichi Medical University Hospital were analyzed. We compared the Ki67 index of endoscopic ultrasonography-fine-needle aspiration biopsy (EUS-FNAB) specimens, surgical specimens, and small tissue specimens hollowed from paraffin blocks of surgical specimens that were substituted for EUS-FNAB specimens ("sub-FNAB"). The sub-FNAB specimens were optically cleared using LUCID (IlLUmination of Cleared organs to IDentify target molecules) and analyzed using 3D immunohistochemistry. RESULTS: The median Ki67 index in FNAB, sub-FNAB, and surgical specimens with conventional immunohistochemistry were 1.2% (0.7-5.0), 2.0% (0.5-14.6), and 5.4% (1.0-19.4), respectively. The median Ki67 index in sub-FNAB specimens with tissue clearing was calculated separately using the total number of cells on multiple images ("multiple slice"), with the image of the fewest positive cells ("coldspot"), and with the image of most positive cells ("hotspot"), which were 2.7% (0.2-8.2), 0.8% (0-4.8), and 5.5% (2.3-12.4), respectively. PanNET grade evaluated for the hotspot of the surgical specimens was significantly more consistent with those of the hotspot than multiple images of sub-FNAB specimens (16/17 vs. 10/17, p = 0.015). Hotspot evaluation using 3D immunohistochemistry of the sub-FNAB specimens showed agreement with the assessment of the surgical specimens (Kappa coefficient: 0.82). CONCLUSIONS: Tissue clearing and 3D immunohistochemistry for the Ki67 index can potentially improve the preoperative evaluation of EUS-FNAB specimens of PanNET in routine clinical practice.

[Incidentally Detected Right Atrial Blood Cyst].

A 48-year-old man underwent computed tomography for the examination of lower back pain, which incidentally detected a cardiac tumor in the right atrium. On echocardiography, the tumor was identified as a 30 mm round mass with a thin wall and iso- and hyper-echogenic contents that originated from the atrial septum. The tumor was successfully removed under cardiopulmonary bypass, and the patient was discharged in good health. The cyst was filled with old blood, and focal calcification was observed. Pathological examination revealed that the cystic wall was composed of thin-layered fibrous tissue lined with endothelial cells. Regarding a treatment, it is reported that early surgical removal is preferable to avoid embolic complications, however it is controversial. Furthermore, it needs to discuss about the difference between fetal/neonatal and adult cases.

Performance of an artificial intelligence-based diagnostic support tool for early gastric cancers: Retrospective study.

OBJECTIVES: Endoscopists' abilities to diagnose early gastric cancers (EGCs) vary, especially between specialists and nonspecialists. We developed an artificial intelligence (AI)-based diagnostic support tool "Tango" to differentiate EGCs and compared its performance with that of endoscopists. METHODS: The diagnostic performances of Tango and endoscopists (34 specialists, 42 nonspecialists) were compared using still images of 150 neoplastic and 165 non-neoplastic lesions. Neoplastic lesions included EGCs and adenomas. The primary outcome was to show the noninferiority of Tango (based on sensitivity) over specialists. The secondary outcomes were the noninferiority of Tango (based on accuracy) over specialists and the superiority of Tango (based on sensitivity and accuracy) over nonspecialists. The lower limit of the 95% confidence interval (CI) of the difference between Tango and the specialists for sensitivity was calculated, with >-10% defined as noninferiority and >0% defined as superiority in the primary outcome. The comparable differences between Tango and the endoscopists for each performance were calculated, with >10% defined as superiority and >0% defined as noninferiority in the secondary outcomes. RESULTS: Tango achieved superiority over the specialists based on sensitivity (84.7% vs. 65.8%, difference 18.9%, 95% CI 12.3-25.3%) and demonstrated noninferiority based on accuracy (70.8% vs. 67.4%). Tango achieved superiority over the nonspecialists based on sensitivity (84.7% vs. 51.0%) and accuracy (70.8% vs. 58.4%). CONCLUSIONS: The AI-based diagnostic support tool for EGCs demonstrated a robust performance and may be useful to reduce misdiagnosis.

Cytological detection of metastatic chordoma cells in pleural effusions: A case report.

Cytological detection of chordoma cells in the serosal cavity is challenging because of its rare presentation. Herein, we report a case of chordoma showing malignant pleural effusion accompanied by pleuropulmonary metastases in a 68-year-old woman. Cytological analysis was performed using pleural fluid obtained following thoracentesis. Conventional cytological staining demonstrated few clusters of large, atypical cells characterized by epithelial cell-like connectivity and rich cytoplasm with foamy and/or multivacuolar changes. The nuclei of these atypical cells were large and either round or oval with no conspicuous irregularities in the nuclear membrane. Periodic acid-Schiff staining of these atypical cells revealed fine granules in the cytoplasm. Giemsa staining showed foamy and/or multivacuolar cytoplasm in these cells, with metachromatic mucoid stroma in the surroundings. Immunocytochemistry analysis using cellblock showed these cells to be positive for broad cytokeratins, epithelial membrane antigen, S100 protein, vimentin, and Brachyury. To the best of our knowledge, this is the first case report in which chordoma cells were cytologically detected in pleural effusions. Our findings also suggest that conventional cytology combined with cellblock immunocytochemistry can increase the accuracy of chordoma cell detection in the serosal cavity.

The pocket-creation method facilitates endoscopic submucosal dissection of gastric neoplasms involving the pyloric ring.

Background and study aims Endoscopic submucosal dissection (ESD) of superficial gastric lesions involving the pyloric ring is difficult. The pocket-creation method (PCM) with a small-caliber-tip transparent hood can overcome this difficulty by compressing the pyloric sphincter applying both traction and counter-traction. The aim of this study is to clarify the usefulness of the PCM for ESD of superficial gastric neoplasms involving the pyloric ring compared to the conventional method (CM). Patients and methods From October 2006 to August 2019, 66 gastric lesions requiring duodenal submucosal dissection beyond the pyloric ring in 66 patients were resected. The CM was mainly performed in the first period (CM group, n = 46) and the PCM in the second period (PCM group, n = 20). We retrospectively reviewed their medical records. Results Although no significant differences were observed in en bloc resection rates between the two groups, the PCM group had a significantly higher R0 resection rate than the CM group ( P  = 0.047). There were no holes in resected specimens in the PCM group while three specimens in the CM group had a hole. The dissection speed in the PCM group tended to be higher than in the CM group, although it did not reach statistical significance ( P  = 0.148). No significant differences were observed for the incidence of adverse events. Conclusions This is the first study reporting the advantages of the PCM over the CM for ESD of gastric lesions involving the pyloric ring. We believe that the PCM is an effective strategy to compress the pyloric sphincter and facilitates R0 resection.

New Diagnostic Approach for Esophageal Squamous Cell Neoplasms Using Linked Color Imaging and Blue Laser Imaging Combined with Iodine Staining.

A 62-year-old man with a flat early esophageal cancer was referred for endoscopic treatment. White light imaging revealed a pale red lesion, whereas linked color imaging (LCI) and blue laser imaging (BLI) yielded purple and brown images, respectively. Iodine staining demonstrated a large unstained area with a homogenous but very weak pink-color sign. This area appeared more clearly as purple and green on LCI and BLI, respectively; however, a different colored portion was observed at the 4 o'clock position inside the iodineunstained area. Histopathology findings of the resected specimen revealed squamous intraepithelial neoplasia at the 4 o'clock position and an esophageal squamous cell carcinoma in the remaining iodine-unstained area. LCI and BLI combined with iodine staining produce characteristic images that overcomes the pink-color sign, reflecting the histological features of a flat esophageal neoplasm. This new method is useful for detailed evaluation of early flat squamous cell neoplasms.

Primary carcinosarcoma of the ureteropelvic junction associated with ureteral duplication: A case report.

RATIONALE: Primary carcinosarcoma of the upper urinary tract is rare. Ureteral duplication is one of the most common urinary tract malformations. Additionally, the association between ureteral duplication and malignancy is unknown. To the best of our knowledge, no cases of malignant tumors diagnosed as carcinosarcoma with ureteral duplication have been reported. We herein report the case of a patient with carcinosarcoma of the ureteropelvic junction associated with incomplete ureteral duplication. PATIENT CONCERNS: A 60-year-old Japanese woman presented with painless gross hematuria. She had a history of total hysterectomy and chemotherapy for endometrioid carcinoma 5 years before. She had no history of occupational chemical exposure. DIAGNOSES: Radiographic imaging revealed right incomplete ureteral duplication, hydronephrosis, and a polypoid tumor in the ureteropelvic junction of the lower moiety of the right kidney. Urine cytology showed a small amount of degenerated atypical epithelial and nonepithelial cells. The transureteral biopsy specimen showed dysplastic urothelial cells and atypical myoid spindle cells. These findings were indefinite for malignancy. INTERVENTIONS: The patient underwent right nephroureterectomy. Pathological examination of the resected tumor showed a biphasic neoplasm composed of carcinomatous and sarcomatous components. The sarcomatous component was immunohistochemically positive for vimentin, desmin, h-caldesmon, and α-SMA and negative for pancytokeratin (AE1/AE3), low molecular weight cytokeratin (CAM 5.2), EMA, E-cadherin, GATA3, uroplakin 2, and p63. Based on these findings, we diagnosed the tumor as carcinosarcoma. OUTCOMES: The postoperative course was uneventful. No additional therapy was administered. The patient has remained alive without recurrence for 21 months since surgery. LESSONS: Carcinosarcoma can arise from ureteral duplication. Although the majority of carcinosarcomas of the upper urinary tract are diagnosed at an advanced stage and have a poor prognosis, some can have a less aggressive course. Further studies are needed to determine the association between ureteral duplication and malignancy.

Prognostic significance of the degree of lymphatic vessel invasion in locally advanced, surgically resectable pancreatic head cancer: A single center experience.

Little is known concerning the prognostic significance of the degree of lymphatic vessel invasion in pancreatic head cancer. To address this gap in knowledge, we retrospectively examined 60 patients with locally advanced, surgically resectable pancreatic head cancer who underwent pancreaticoduodenectomy and lymph node (LN) dissection.All cases were histopathologically diagnosed as ductal adenocarcinoma, stage II (25 pT3N0 cases, 35 pT3N1 cases). The following variables were investigated: age; sex; neoadjuvant therapy; adjuvant therapy; tumor size; tumor grade; invasion into the serosa, retropancreatic tissue, duodenum, bile duct, portal venous system and perineural area; cut margins; LN metastasis; and the number of invaded lymphatic vessels (LVI-score).Univariate analysis demonstrated that LN metastasis and an LVI-score ≥5 were significantly associated with poor disease-free survival. Multivariate Cox regression analysis confirmed that LN metastasis and an LVI-score ≥7 were significantly associated with poor disease-free survival. Additionally, LVI-scores ≥9 and ≥10 were comparable to or surpassed the significance of LN metastasis based on the hazard ratio. Univariate analysis demonstrated that tumor size >30 mm, duodenal invasion, LN metastasis and an LVI-score ≥2 were significantly associated with poor overall survival. Multivariate Cox regression analysis confirmed that LN metastasis and LVI-scores ≥9 and ≥10 were significantly associated with poor overall survival, and an LVI-score ≥10 was comparable to or surpassed the significance of LN metastasis based on the hazard ratio.Our study strongly suggests that a high degree of lymphatic vessel invasion is associated with a poor prognosis in patients with locally advanced, surgically resectable pancreatic head cancer.