Patient-derived tumoroid models of pulmonary large-cell neuroendocrine carcinoma: a promising tool for personalized medicine and developing novel therapeutic strategies

Pulmonary large-cell neuroendocrine carcinoma (LCNEC), a disease with poor prognosis, is classified as pulmonary high-grade neuroendocrine carcinoma, along with small-cell lung cancer. However, given its infrequent occurrence, only a limited number of preclinical models have been established. Here, we established three LCNEC tumoroids for long-term culture. Whole-exome sequencing revealed that these tumoroids inherited genetic mutations from their parental tumors; two were classified as small-cell carcinoma (S-LCNEC) and one as non-small cell carcinoma (N-LCNEC). Xenografts from these tumoroids in immunodeficient mice mimicked the pathology of the parent LCNEC, and one reproduced the mixed-tissue types of combined LCNEC with a component of adenocarcinoma. Drug sensitivity tests using these LCNEC tumoroids enabled the evaluation of therapeutic agent efficacy. Based on translational research, we found that a CDK4/6 inhibitor might be effective for N-LCNEC and that Aurora A kinase inhibitors might be suitable for S-LCNEC or LCNEC with MYC amplification. These results highlight the value of preclinical tumoroid models in understanding the pathogenesis of rare cancers and developing treatments. LCNEC showed a high success rate in tumoroid establishment, indicating its potential application in personalized medicine.

Establishment and characterization of novel high mucus-producing lung tumoroids derived from a patient with pulmonary solid adenocarcinoma

Among mucus-producing lung cancers, invasive mucinous adenocarcinoma of the lung is a rare and unique subtype of pulmonary adenocarcinoma. Notably, mucus production may also be observed in the five subtypes of adenocarcinoma grouped under the higher-level diagnosis of Invasive Non-mucinous Adenocarcinomas (NMA). Overlapping pathologic features in mucus-producing tumors can cause diagnostic confusion with significant clinical consequences. In this study, we established lung tumoroids, PDT-LUAD#99, from a patient with NMA and mucus production. The tumoroids were derived from the malignant pleural effusion of a patient with lung cancer and have been successfully developed for long-term culture (> 11 months). Karyotyping by fluorescence in situ hybridization using an alpha-satellite probe showed that tumoroids harbored aneuploid karyotypes. Subcutaneous inoculation of PDT-LUAD#99 lung tumoroids into immunodeficient mice resulted in tumor formation, suggesting that the tumoroids were derived from cancer. Xenografts from PDT-LUAD#99 lung tumoroids reproduced the solid adenocarcinoma with mucin production that was observed in the patient's metastatic lymph nodes. Immunoblot analysis showed MUC5AC secretion into the culture supernatant of PDT-LUAD#99 lung tumoroids, which in contradistinction was barely detected in the culture supernatants of NCI-A549 and NCI-H2122 pulmonary adenocarcinoma cells known for their mucin-producing abilities. Here, we established a novel high-mucus-producing lung tumoroids from a solid adenocarcinoma. This preclinical model may be useful for elucidating the pathogenesis of mucus-producing lung cancer.

A Study of the Risk Factors for 402 Patients with Esophageal Squamous Cell Carcinoma - A Retrospective Comparison with Health Checkup Participants

Objective Esophageal cancer is a gastrointestinal cancer with a poor prognosis. However, it is curable and can be treated endoscopically if it is detected at an early stage. The objective of this study was to identify the factors that contribute to early detection. Methods From April 2011 to December 2019, we retrospectively investigated consecutive patients diagnosed with esophageal squamous cell carcinoma (ESCC) through upper gastrointestinal endoscopy at two hospitals of Kawasaki Medical University based on medical records. The factors contributing to the early detection of ESCC were investigated by comparing patients with ESCC with those undergoing health checkups in whom no organic lesions were found in the upper gastrointestinal tract on endoscopy (controls). Patients Factors contributing to early detection were examined in 402 ESCC cases and 391 sex- and age-matched controls, and early and advanced cancers were compared along with the risk factors for ESCC. Results A multivariate analysis showed that alcohol consumption and smoking, concomitant cancer of other organs, and a low body mass index (BMI) were factors associated with ESCC (odds ratio [OR], 4.65; 95% confidence interval [CI], 2.880-7.520, OR,3.63; 95% CI, 2.380-5.540, OR, 2.09; 95% CI, 1.330-3.270, OR, 6.38; 95% CI, 3.780-10.800), whereas dyslipidemia was significantly less common in patients with ESCC (OR, 0.545; 95% CI, 0.348-0.853). Comparing early and advanced cancers, a history of endoscopic screening was the only factor involved in early detection (OR, 7.93; 95% CI, 4.480-14.00). Conclusion The factors associated with ESCC include alcohol consumption, smoking, concomitant cancer of other organs, and a low BMI. Endoscopy in subjects with these factors may therefore be recommended for the early detection of ESCC.

Appendiceal mucocele pathologically classified as appendiceal epithelial hyperplasia and preoperatively diagnosed by contrast-enhanced ultrasonography: A case report

We report a patient with a mucocele with diffuse wall thickening diagnosed by transabdominal ultrasonography and contrast-enhanced ultrasonography. Transabdominal ultrasonography showed diffuse thickening of the entire appendix wall and an anechoic area that appeared to be fluid collected throughout the appendix lumen. However, the "onion skin sign" was not detected. Contrast-enhanced ultrasonography combined with superb microvascular imaging revealed abundant mucosal blood flow and no abnormal vascular network within the mucosa of the appendix wall. We preoperatively diagnosed a mucocele complicated by acute and chronic appendicitis, and ileocecal resection was performed. Macroscopic and microscopic findings of the resected specimens demonstrated that the appendiceal wall was diffusely thickened, with fibrosis and inflammatory cell infiltration, and that the appendiceal root rumen was narrowed with epithelial hyperplasia. No neoplastic changes were observed. The cause of the appendiceal mucocele was likely fibrosis and stenosis at the root of the appendix due to initial acute appendicitis.

Immunohistological analysis of B7-H4, IDO1, and PD-L1 expression and tumor immune microenvironment based on triple-negative breast cancer subtypes

BACKGROUND

B7 homolog 4 (B7-H4) and indoleamine 2,3-dioxygenase (IDO1) are factors involved in the inhibition of antitumor activity and are new therapeutic targets for immune checkpoint therapy. Our study aimed to simultaneously investigate the interrelationship among B7-H4, IDO1 and programmed cell death ligand 1 (PD-L1) expression in triple-negative breast cancer (TNBC), including tumor immune microenvironment (TIME) and TNBC subtypes.

METHODS

Immunostaining for PD-L1, B7-H4, and IDO1 was performed on whole-slide sections of 119 cases of TNBC. The TIME was evaluated based on stromal tumor infiltrating lymphocytes (sTILs; %), pattern classification of TILs, tumor-stroma ratio (TSR), and tertiary lymphoid structure (TLS). TNBC subtypes were also determined by immunohistochemistry analysis of cytokeratin 5/6 and androgen receptor (AR) expression.

RESULTS

B7-H4 expression was significantly higher in cases with a combined positive score cutoff of 5 for PD-L1 (clone 28-8; p = 0.021), inflamed TIL pattern (p = 0.007), and TLS ≥ 4 (p = 0.006). B7-H4 expression was higher in case of CK5/6 ≥ 10 (p = 0.035). The H-scores of AR and B7-H4 were inversely correlated (ρ = - 0.509, p < 0.001). B7-H4 and IDO1 expression levels were inversely correlated in cases with AR < 10 (ρ = - 0.354, p < 0.001).

CONCLUSIONS

These results suggest that considering the TIL pattern and TLS and identifying the expression of PD-L1 and the basal-like type are useful for estimating B7-H4 expression. In addition, luminal androgen receptor (LAR)-type is frequently deficient in B7-H4 expression. In non-LAR types, B7-H4 and IDO1 expression are exclusive.

Protease-Activated Receptor 1 (PAR1) Expression Contributes to HPV-Associated Oropharyngeal Cancer Prognosis

BACKGROUND

Human papillomavirus (HPV)-associated oropharyngeal cancer occasionally has a poor prognosis, making prognostic risk stratification crucial. Protease-activated receptor-1 (PAR1) is involved in carcinogenesis, and its expression is regulated by alpha-arrestin domain-containing protein 3 (ARRDC3). It is also involved in the tumor microenvironment. We sought to evaluate the predictive ability of PAR1, ARRDC3, and tumor-infiltrating lymphocyte (TIL) scores in patients with oropharyngeal, hypopharyngeal, and uterine cervical cancers, serving as comparators for HPV-associated oropharyngeal cancer.

METHODS

Immunohistochemical analysis of p16, ARRDC3, and PAR1 expression was performed on 79 oropharyngeal, 44 hypopharyngeal, and 42 uterine cervical cancer samples. The TIL scores were assessed and classified into the following groups based on invasion: low: 0-10%, medium: 20-40%, and high: > 50%. For prognostic analysis, the three groups were evaluated by dividing them into low, medium, and high categories, or alternatively into two groups using the median value as the cutoff.

RESULTS

p16 was expressed in 44 (56%) oropharyngeal, 8 (18%) hypopharyngeal, and all uterine cervical cancer samples. ARRDC3 was detected in 39 (49%) oropharyngeal, 25 (57%) hypopharyngeal, and 23 (55%) uterine cervical cancer samples. PAR1 was expressed in 45 (57%) oropharyngeal, 22 (50%) hypopharyngeal, and 22 (50%) uterine cervical cancer samples. Patients diagnosed with p16-positive oropharyngeal cancer had a substantially improved prognosis compared to those diagnosed with p16-negative cancer. The PAR1-negative cases had a considerably improved prognosis compared to the positive cases (disease-specific survival [DSS] and -negative cases (disease-free survival [DFS]). Multivariate analysis revealed that ARRDC3-positive cases had an appreciably better DSS prognosis than patients with p16-negative oropharyngeal cancers. PAR1-positive patients among patients with p16-positive oropharyngeal cancer had a poor prognosis. With respect to DFS, patients with PAR1-positive and p16-negative oropharyngeal cancer had a 35-fold higher recurrence rate than those with PAR1-negative and p16-negative oropharyngeal cancer.

CONCLUSION

Our results suggest that PAR1 expression affects the prognosis and recurrence rate of HPV-associated oropharyngeal cancer.

A surgical case of pulmonary adenocarcinoma in the right upper lobe associated with a systemic artery-to-pulmonary artery fistula

A 52-year-old female never-smoker with an abnormal shadow in the right lung detected on radiography was referred to our institution. Contrast-enhanced computed tomography revealed an irregular nodule in the upper lobe of the right lung, suggestive of a pulmonary vascular abnormality. Angiography revealed a direct communication between the right internal mammary artery (IMA) and the right upper lobe pulmonary artery branches, with dilated and tortuous vascular proliferation. As multiple branch arteries were seen flowing into the upper lobe from the IMA, transcatheter selective embolization of these vessels and right upper lobectomy by video-assisted thoracoscopic surgery were performed. Contrary to the clinical diagnosis, the pathological finding was a pulmonary adenocarcinoma of the right upper lobe. Additional lymph node dissection was performed later. We report an extremely rare and unprecedented case of pulmonary adenocarcinoma fed by the right IMA, with a literature review.

[Three Cases of Appendiceal Goblet Cell Adenocarcinoma in Our Institution]

Appendiceal goblet cell adenocarcinoma(AGCA)is a newly designated pathological term adopted in the 5th edition of the WHO classification. It is synonymous with goblet cell carcinoid, which was previously categorized as a part of appendiceal carcinoid. However, since 2018, it has been classified as a subtype of adenocarcinoma. We have experienced 3 cases of this relatively rare tumor, of which 2 were initially diagnosed with acute appendicitis and were diagnosed with AGCA by pathological examination after an emergency appendectomy. Each of them underwent additional ileocolic resection with lymph node dissection as the second surgery. In the 3rd case, an appendiceal tumor was detected during preoperative examinations for an ovarian tumor. Staging laparoscopy revealed comorbid peritoneal dissemination, and only the appendix and right ovary were removed in the consecutive surgery. The ovarian tumor was pathologically diagnosed as a metastasis of AGCA. In this case, the introduction of oxaliplatin-based systemic chemotherapy after surgery achieved a complete response after more than 2 years. Although no recurrence has been observed in all 3 cases to date, AGCA is considered highly malignant compared to conventional appendiceal carcinoids. Therefore, it is crucial to practice multidisciplinary treatments, including sufficient radical surgery based on a precise diagnosis of AGCA, as is performed for advanced colorectal cancer.

The inclusion of nuclear area improves the Paris system for reporting urinary cytology

OBJECTIVE

The Paris System for Reporting Urinary Cytology (TPS) is a well-known urinary diagnostic model; however, occasional false-positives are a problem. To address this issue, we developed an improved algorithm (IA), based on additional cytological features, for TPS diagnosis.

METHODS

Cytological features were evaluated in 29 hard-to-classify cases, including 22 malignant cases and seven benign cases, using image analysis. The optimal IA was determined using the area under the receiver operating characteristic curve as an index. Re-evaluation was performed by applying measured values to the TPS and IA algorithms.

RESULTS

Using TPS, 12 of the 22 malignant cases were reassigned to a more appropriate category, and the remaining 10 malignant cases remained hard-to-classify. Two of the seven benign cases were classified as suspicious for high-grade urothelial carcinoma, and the remaining five benign cases remained in the original category. The IA, which included nuclear area as a parameter, showed the same diagnostic sensitivity as TPS, and three of the seven benign cases were reassessed as negative. Thus, the positive and negative predictive values of the IA were higher than those of TPS (84.6% and 100% vs 75.9% and 0%).

CONCLUSIONS

The newly developed IA is a practical algorithm with which to address the limitations of TPS and thus may contribute to improved diagnostic accuracy.

Benefit of Continuation of Low-Dose Imatinib for Gastrointestinal Stromal Tumors despite Adverse Events with Regular-Dose Imatinib

Tyrosine kinase inhibitors (TKIs) such as imatinib improve the prognosis of patients with gastrointestinal stromal tumors (GISTs). However, treatment options for GISTs are still limited, and the continuation of TKIs is difficult due to adverse events in some cases. The effectiveness of low-dose imatinib is unclear. We report 2 cases to show effectiveness of low-dose imatinib in patients with adverse events. The first case is a male in his early 60s with a history of intestinal GIST resection who was diagnosed with recurrent GIST with peritoneal dissemination. He was started on low-dose imatinib (300 mg) because of a history of subconjunctival hemorrhage after receiving postoperative imatinib. Follow-up contrast-enhanced ultrasonography revealed that the tumors had shrunk in size and number after 2 months of treatment with 300-mg imatinib. He continued this treatment and showed partial response for 8 months. The second case is a female in her late 70s with rectal GIST who was treated with imatinib 400 mg. Due to a severe skin lesion, she changed her treatment to sunitinib 2 months after initiation. However, new metastasis in the liver was confirmed after 4 months of administration of sunitinib. She underwent surgical esection of the rectal tumor to reduce the volume. After the surgery, low-dose imatinib (300 mg) with oral steroids was adopted. Follow-up confirmed the absence of recurrence at the rectum and no increase in hepatic tumor size for 18 months. Aggressive treatment with low-dose imatinib instead of discontinuation or alteration of treatment may benefit patients with unresectable and postoperative GISTs with sensible mutation to imatinib.

A Case of Autoimmune Gastritis and Hepatitis with Enlarging Gastric Polyps after Reducing the Dose of Prednisolone

Autoimmune gastritis is immune-mediated gastritis that destroys the oxyntic mucosa. Autoimmune hepatitis is an inflammatory liver disease caused by an autoimmune reaction. These diseases share similar pathogeneses as organ-specific autoimmune disorders; however, cases involving both diseases are quite rare and scarcely reported. Herein, we report a patient with concurrent autoimmune gastritis and hepatitis who developed enlargement of hyperplastic polyps and progression of gastric atrophy. The patient was a 79-year-old female referred to our hospital for the treatment of hyperplastic polyps detected on a follow-up upper gastrointestinal endoscopy. The patient's previous upper gastrointestinal endoscopy from 3 years prior revealed small hyperplastic polyps and no mucosal atrophy. However, the current upper gastrointestinal endoscopy revealed three 10-mm red polyps, severe mucosal atrophy in the corpus, and mild atrophy in the antral area. In addition, biopsy samples from the gastric body revealed decreased parietal cells and diffuse lymphocytic infiltration of the deep mucosa. Further, chromogranin A-positive endocrine cell micronests and enterochromaffin-like cell hyperplasia were detected. After confirming the diagnosis of autoimmune gastritis, endoscopic mucosal resection was performed for all the polyps, which were histopathologically diagnosed as hyperplastic polyps without malignancy. Therefore, clinicians should consider autoimmune gastritis for enlarged hyperplastic polyps and gastric atrophy progression.

Development, Disappearance, and Clinical Course of Melanosis Coli: Sex Differences in the Progression of Severity

Melanosis coli (MC) is an acquired colorectal disorder visualized as colonic mucosa pigmentation. Disease severity is confirmed based on MC depth, shape, and coloration, although the clinical course is not fully understood. This study sought to clarify characteristics of MC development and disappearance and to investigate its clinical course and severity. Contributors to MC grade progression were explored. This study reviewed MC cases discovered via colonoscopy at a single institution over a 10-year period. Of all 216 MC cases, 17 developing and 10 disappearing cases were detected. Anthranoid laxative use was a key factor: 29.4% of the developing cases had used such agents before the initial MC diagnosis, whereas 40% of disappearing cases had discontinued anthranoids prior to detection of MC disappearance. Among 70 grade I cases, progression to grade II occurred in 16 cases during a mean follow-up of 3.67±2.1 years (rate of progression=22.8%). Males more commonly showed progressive than stable grade I cases, and the probability of progression was higher for male than for female cases. An association between anthranoid administration and MC presence was presumed, and grade I MC was found to progress in severity over 5 years.

Two Cases of Acute Gastric Mucosal Lesions Due to Helicobacter pylori Infection Confirmed to be Transient Infection

Two adult cases of acute gastric mucosal lesions (AGML) caused by Helicobacter pylori infection were confirmed by spontaneous eradication during the follow-up period. The clinical course of the initial infection by H. pylori in adults with AGML remains unclear, whether it is transient or progresses to a persistent infection. In these two reported cases, gastric biopsies at the time of the onset revealed the presence of H. pylori; however, serum H. pylori antibodies performed at the same time were negative. Retesting for H. pylori serum antibody, after six months in one and after two months in the other, was negative, confirming spontaneous eradication.

IgG4-related lung disease with multifocal pulmonary consolidations near the pleura: A case report

RATIONALE

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a systemic immune-mediated condition that can cause fibroinflammatory lesions in multiple organs. Approximately 35% of IgG4-RD patients have some symptoms in the chest and IgG4-related lung disease (IgG4-RLD) is observed in about 10% of IgG4-RD cases. In addition, it is thought that glucocorticoid therapy is effective for IgG4-RD and IgG4-RLD. It is difficult to diagnose IgG4-RLD complicated with another lung disease.

PATIENT CONCERNS

An 85-year-old Japanese man was hospitalized due to pulmonary consolidations just below the pleura in chest computed tomography while being treated with antibiotics. Previously, an upper lobectomy of the right lung was performed for an upper lung mucinous adenocarcinoma, and he was diagnosed with chronic obstructive pulmonary disease. Although he took antibiotics before admission, C-reactive protein levels were elevated.

DIAGNOSIS

IgG4 levels were also elevated (IgG4; 733 mg/dL), and lung biopsy histology showed an abundance of IgG4-positive plasma cell infiltration; about 40% of the affected area was occupied by such infiltration. Based on such findings, we finally diagnosed him as IgG4-RLD.

INTERVENTIONS

We administered 20 mg/d prednisolone.

OUTCOMES

About 2 weeks after administration of prednisolone by intravenous injection, his multifocal pulmonary consolidations just below the pleura were markedly improved and his pulmonary symptoms disappeared. Four weeks after glucocorticoid therapy, IgG4 levels decreased from 831 mg/dL (peak) to 547 mg/dL.

LESSONS

We should consider IgG4-RLD, a rare disease, when lesions are detected as pulmonary consolidations near the pleura and are unresponsive to antibiotic therapy. Glucocorticoid therapy, however, is very effective for such IgG4-RLD.

Brain and Adrenal Metastasis From Unknown Primary Tumor: A Case Report

The clinical management of brain metastasis (BM) and adrenal metastasis (AM) of cancer of unknown primary (CUP) can be challenging. A 73-year-old man presented to the hospital with sudden-onset hemiplegia. His laboratory data were normal, except for elevated levels of carcinoembryonic antigen (CEA) (33.8 ng/mL). Contrast-enhanced magnetic resonance imaging revealed a 2-cm mass with ring enhancement in the right parietal lobe and extensive vasogenic edema around the tumor. The lesion was diagnosed as BM; however, we could not detect the primary origin by fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT). Stereotactic radiotherapy was then administered, resulting in reduced tumor size and relief of symptoms. Follow-up after one year revealed an elevated CEA level (148.6 ng/mL) and remarkable fluorodeoxyglucose (FDG) uptake in the right adrenal gland, with an area of enhancement of 20 mm, on FDG-positron emission tomography computed tomography, with normal findings in other distant organs. He underwent adrenalectomy, and the adrenal tumor was diagnosed as a poorly differentiated adenocarcinoma likely of lung origin based on the histopathologic and immunohistochemistry findings of cytokeratin (CK) 7 (+), CK 20 (-), thyroid transcription factor-1 (TTF-1) (+), inhibin (-), napsin A (+), prostate-specific antigen (PSA) (-), caudal type homeobox 2 (CDX-2) (-), synaptophysin (-), and p40 (-). Metastatic tumors of unknown primary origin remain latent. Aggressive treatment of these lesions can be beneficial for symptom relief, diagnosis, and prolongation of survival.

Subjective factors affecting prognosis of 469 patients with esophageal squamous cell carcinoma: a retrospective cohort study of endoscopic screening

Background

To date, no in-depth studies have focused on the impact of various clinical characteristics of esophageal squamous cell carcinoma (ESCC), including its association with subjective symptoms, on patient prognosis. We aimed to investigate the clinical factors that affect the prognosis of patients with ESCC and to clarify how subjective symptoms are related to prognosis.

Methods

We retrospectively evaluated the clinical records of 503 consecutive patients with ESCC from April 2011 to December 2019. Six established prognostic factors for ESCC (body mass index, alcohol drinking, cigarette smoking, sex, clinical stage, and age) and subjective symptoms were used to subgroup patients and analyze survival differences. Next, the patients were divided into two groups: a symptomatic group and an asymptomatic group. In the symptomatic group, differences in the incidence of subjective symptoms according to tumor size, tumor location, macroscopic tumor type, and clinical stage were examined. Finally, subjective symptoms were divided into swallowing-related symptoms and other symptoms, and their prognosis was compared.

Results

Multivariate Cox regression analysis identified sex [hazard ratio (HR) 1.778; 95% CI 1.004–3.149; p = 0.049], TNM classification (HR 6.591; 95% CI 3.438–12.63; p < 0.001), and subjective symptoms (HR 1.986; 95% CI 1.037–3.803; p = 0.0386) as independent risk factors for overall survival. In the symptomatic group, the mean time from symptom onset to diagnosis was 2.4 ± 4.3 months. The incidence of subjective symptoms differed by clinical stage, and the prognosis of patients with swallowing-related symptoms was significantly worse than that of patients with other symptoms.

Conclusion

The results of this study suggest that screening by upper gastrointestinal endoscopy, independent of subjective symptoms (especially swallowing-related symptoms), may play an important role in the early detection and improvement of prognosis of ESCC, although further validation in a large prospective study is needed.

<b><i>Helicobacter pylori</i></b>-Negative Advanced Gastric Cancer Arising from the Gastric Mucosa without Inflammation, Atrophy, or Intestinal Metaplasia

Gastric cancer is strongly associated with atrophic gastritis associated with <i>Helicobacter pylori</i> infection. The eradication of <i>H. pylori</i> has been reported to improve inflammation of the gastric mucosa, atrophy, and intestinal metaplasia and has also been shown to inhibit the development and growth of gastric cancer. Advanced gastric cancer from <i>H. pylori</i>-negative mucosa without inflammation, atrophy, or intestinal epithelialization is rarely found. We report on two cases of advanced gastric cancer without endoscopic evidence of gastric mucosal atrophy. One case was in the gastric angle 9 years after <i>H. pylori</i> eradication and the other case was in the pylorus of an uninfected stomach. Although gastric cancer is strongly associated with atrophic gastritis caused by <i>H. pylori</i> infection, postoperative histopathological examination of the stomach in both cases showed no inflammation, atrophy, or intestinal metaplasia. Poorly differentiated adenocarcinomas were confirmed at the microscopic level, and both cases were determined to be type 4 using the Borrmann classification. There is a body of evidence showing that <i>H. pylori</i> infection can cause gastric cancer and is the most prevalent infection-induced cancer in the world. The 2 cases here displayed different carcinogenesis than gastric mucosal atrophy caused by <i>H. pylori</i> infection. With the spread of <i>H. pylori</i> eradication treatments and an increasing number of uninfected patients, these case reports can contribute to future strategies for the diagnosis of gastric cancer.

Endoscopic features and clinical importance of autoimmune gastritis

Autoimmune gastritis (AIG) is a special type of chronic gastritis characterized by autoimmune disorders caused by cellular immunity, resulting in the destruction of parietal cells and production of antiparietal cell antibodies. Endoscopic findings of AIG are mainly characterized by corpus-dominant advanced atrophy. The antral area is generally considered to have no or mild atrophy; however, there are cases wherein the gastric mucosa is red or faded due to past infection with Helicobacter pylori or bile reflux. Currently, there are no diagnostic criteria for AIG in Japan, and it is important to make a diagnosis based on the presence of gastric autoantibodies and characteristic endoscopic and histological findings. AIG is associated with gastric cancer, neuroendocrine tumors (NETs), and other autoimmune diseases, such as thyroid diseases, anemia, and neurological symptoms due to impaired absorption of iron and vitamin B₁₂ , and thus requires systemic treatment. The significance of diagnosing AIG is to include patients as a high-risk group for the development of gastric cancer and gastric NETs, provide an opportunity to detect autoimmune endocrine diseases, and initiate therapeutic intervention before anemia and neurological symptoms develop. It is important to pay close attention to the occurrence of AIG comorbidities not only at the time of AIG diagnosis but also during follow-up after detection.

Neuroendocrine tumor secondary to pulmonary hypoplasia: A case report

Pulmonary hypoplasia is diagnosed during the perinatal period and is a cause of death in newborns. However, these developmental abnormalities are diagnosed in adulthood in some cases. A 70‐year‐old male smoker was diagnosed with stage IIIA pulmonary adenocarcinoma in the right upper lobe with right middle lobe hypoplasia. He subsequently underwent right upper and middle lobectomy with lymph node dissection by video‐assisted thoracoscopic surgery. In addition to an invasive adenocarcinoma in the right upper lobe, pathological examination of the hypoplastic lobe revealed neuroendocrine hyperplasia, as well as tumorlets and a typical carcinoid. Eight cases of pulmonary neuroendocrine tumors that developed from pulmonary hypoplasia have been reported to date. Interestingly, all but one case occurred in the right middle lobe. Neuroendocrine cell hyperplasia has been reported to develop in hypoplastic lungs postnatally; therefore, we speculated that the lesion was the origin of these neuroendocrine tumors. Moreover, the pathological findings suggested that atelectasis was involved in the pathogenesis of this rare condition. In adults, when lobar hypoplasia is diagnosed, neuroendocrine tumors should be anticipated.

Diagnosis of Fibrotic Distal Ileum Stenosis after Ischemic Enteritis Using Transabdominal Ultrasonography

Ischemic enteritis (IE) is a rare disorder which is caused by inadequate blood flow to small intestine. The diagnostic procedure of this disease has not sufficiently established because of its rarity. Here, we report a case of IE in a hemodialysis-dependent 70-year-old man and summarize the diagnostic options for IE. The patient was admitted to our hospital because of acute abdominal distention and vomiting. He presented with mild tenderness in the lower abdomen and slightly elevated C-reactive protein level as revealed by blood tests. Radiographic imaging showed small bowel obstruction due to a stricture in the distal ileum. Contrast-enhanced abdominal ultrasonography revealed a 7-cm stenotic site with increased intestinal wall thickening, which preserved mucosal blood perfusion. Elastography revealed a highly elastic alteration of the stenotic lesion, indicating benign fibrotic changes resulting from chronic insufficient blood flow. Based on a clinical diagnosis of IE with fibrous stenosis, a partial ileostomy was performed. After surgical treatment, oral intake was initiated without recurrence of intestinal obstruction. Pathological findings revealed deep ulceration with inflammatory cell infiltration at the stenotic site. Occlusion and hyalinization of the venules in the submucosal layer indicated IE. In addition to current case, we reviewed past case reports of IE. Through this case presentation and literature review, we summarize the usefulness and safety of transabdominal ultrasonography for diagnosing IE.

Colorectal neoplasms in melanosis coli: a survey in Japan and a worldwide meta-analysis

PURPOSE

The association between melanosis coli (MC) and colorectal neoplasms remains unclear. Thus, we primarily aimed to clarify the epidemiology of MC in the Japanese population, identify the relationship between the use of anthranoids and MC, and determine the prevalence of detected intestinal lesions in patients with MC. We subsequently conducted a meta-analysis of published data, including our results, to summarize the influence of MC on the prevalence of colonic neoplasms.

METHODS

We conducted a retrospective survey in Japan to investigate the effects of MC on intestinal disorders. The prevalence of colorectal neoplasms and ileal ulcers was evaluated by colonoscopy, and the clinical characteristics of the participants were investigated using an electronic database. Odds ratios for colorectal neoplasms were calculated. We also performed a meta-analysis using Review Manager to reveal the comprehensive relationship between MC and colorectal neoplasms.

RESULTS

We enrolled 690 Japanese participants in the primary study. The prevalence of regular anthranoid use was significantly higher in the MC group than in the control group (50.9% vs. 6.5%, p < 0.01). Hyperplastic/inflammatory polyps and adenomas were more frequently detected in the MC group than in the control group. In a meta-analysis of five studies, a significantly higher prevalence of hyperplastic/inflammatory polyps and adenomas was reported in the MC group than in the control group, while the incidence of adenocarcinoma was not significantly different between the two groups.

CONCLUSION

Although hyperplastic polyps and adenomas were more frequently detected in MC patients, MC was not associated with an elevated risk of colorectal cancer.

MRI and CT features of a malignant myoepithelioma of the scrotum: A case report and literature review

Malignant myoepithelioma of the scrotum is extremely rare. We report the case of a 51-year-old man with malignant myoepithelioma of the scrotum, wherein computed tomography and magnetic resonance imaging revealed a lobulated soft tissue mass with calcification, cystic component, and solid component with gradual contrast enhancement on dynamic contrast-enhanced scans. The patient presented with scrotal induration, and there was no elevation of tumor markers and no evidence of a metastatic lesion on computed tomography and magnetic resonance imaging. Histopathological examination of the resected scrotal specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was malignant myoepithelioma of the scrotum. This case shows that scrotal malignant myoepithelioma might appear as a well-defined lobulated mass with cystic regions. We conjecture that the enhancement pattern and apparent diffusion coefficient values can be potential markers for scrotal myoepithelial tumors.

[Three Cases of Colon Medullary Carcinoma in Our Institution]

Medullary carcinoma of the colorectum is a relatively new histological subtype that was first described in the eighth edition of the Japanese classification of colorectal, appendiceal, and anal carcinoma. In our institution, only 3 cases of medullary carcinoma have been diagnosed since 2013. Case #1 was a 93-year-old woman with type 1 ascending colon cancer; she received a right hemicolectomy. The tumor invaded the subserosal layer, but no lymph nodal metastasis was observed. Case #2 was a 91-year-old woman with obstructive ascending colon cancer. After intracolonic decompression using the transnasal ileus tube, she received a right hemicolectomy. This tumor also extended into the subserosal layer without lymph nodal metastasis. Case #3 was a 65-year-old woman with a family history of cancers; she received a right hemicolectomy for cecal cancer with an aberrant elevation of serum tumor markers such as CEA and CA19-9. The tumor invaded the subserosal layer with regional lymph nodal metastases. Notably, these 3 cases were females who had right-sided tumors and all showed diminished expressions of MLH1 and PMS2 mismatch repair-associated genes, together with epidemiological characteristics of medullary carcinoma. Herein, we report their pathological features along with the corresponding literature review.

A case of eosinophilic gastroenteritis with high PET-CT accumulation treated by P-CAB

Eosinophilic gastroenteritis (EGE) can present findings on computed tomography (CT) images that resemble malignant tumors. EGE is generally treated with systemic oral steroid administration, which is reportedly effective in relieving symptoms at least temporarily. Here, we report a case of EGE that mimicked malignant lymphoma in a gastroduodenal lesion, in which treatment with a potassium-competitive acid blocker without systemic oral steroid administration relieved the symptoms and reversed the initial image findings. A 56-year-old woman became aware of discomfort in her epigastric region, which gradually worsened. This case showed antroduodenal wall thickness, which mimicked a malignant lymphoma with increased F-18 fluorodeoxyglucose (FDG) uptake by positron emission tomography/computed tomography (PET/CT). An upper gastrointestinal endoscopy revealed protruding erosions in the antrum and severe edematous changes in the duodenum. Extensibility of the normal gastric wall by insufflation also occurred. However, an abdominal ultrasound indicated wall thickening with a preserved wall structure. Histological examinations showed a large amount of eosinophil infiltration, mainly in the gastroduodenal mucosa, without malignant cells. Thus, we made a final diagnosis of EGE. The patient was then administered 20 mg vonoprazan fumarate per day because she refused steroid treatment and because the pathological lesion was also localized from the duodenum to the antrum. After 3 weeks of potassium-competitive acid blocker treatment, her symptoms were alleviated, and the degree and extent of thickening of the gastroduodenal wall in upper gastrointestinal endoscopy and ultrasonographic image findings had remarkably improved.

IgA Vasculitis in a Lung Cancer Patient During Chemoradiotherapy

A 72-year-old man with locally advanced lung squamous cell carcinoma experienced red purpura on the lower legs and hematuria when the disease progressed during definitive chemoradiotherapy. He had renal dysfunction and proteinuria. Biopsy specimens of the skin lesion and kidney revealed immunoglobulin A vasculitis. Potential causes such as paraneoplastic syndrome and cancer treatment have been proposed. The administration of steroids rapidly improved the symptoms. The presentation of immunoglobulin A vasculitis is accompanied by malignancies. Clinicians should keep this syndrome in mind, even during curative-intent treatment.

Clinical application of a lung cancer organoid (tumoroid) culture system

Despite high expectations for lung tumoroids, they have not been applied in the clinic due to the difficulty of their long-term culture. Here, however, using AO (airway organoid) media developed by the Clevers laboratory, we succeeded in generating 3 lung tumoroid lines for long-term culture (>13 months) from 41 lung cancer cases (primary or metastatic). Use of nutlin-3a was key to selecting lung tumoroids that harbor mutant p53 in order to eliminate normal lung epithelial organoids. Next-generation sequencing (NGS) analysis indicated that each lung tumoroid carried BRAFG469A, TPM3-ROS1 or EGFRL858R/RB1E737*, respectively. Targeted therapies using small molecule drugs (trametinib/erlotinib for BRAFG469A, crizotinib/entrectinib for TPM3-ROS1 and ABT-263/YM-155 for EGFRL858R/RB1E737*) significantly suppressed the growth of each lung tumoroid line. AO media was superior to 3 different media developed by other laboratories. Our experience indicates that long-term lung tumoroid culture is feasible, allowing us to identify NGS-based therapeutic targets and determine the responsiveness to corresponding small molecule drugs.

Gastric Hyperplastic Polyps after Argon Plasma Coagulation for Gastric Antral Vascular Ectasia in Patients with Liver Cirrhosis: A Case Suggesting the "Gastrin Link Theory"

We herein report a case of gastric hyperplastic polyps after argon plasma coagulation (APC) for gastric antral vascular ectasia (GAVE) in the antrum of a 65-year-old man with liver cirrhosis and hypergastrinemia induced by long-term proton pump inhibitor (PPI) use. Two years after APC therapy, endoscopy demonstrated multiple gastric polyps in the antrum and angle. A gastric polyp biopsy indicated foveolar epithelium hyperplasia, which was diagnosed as gastric hyperplastic polyps. One year after switching to an H2 blocker antagonist, endoscopy revealed that the polyps and GAVE had disappeared, with normal gastrin levels suggesting that PPI-induced hypergastrinemia had caused gastric hyperplastic polyps after APC therapy, and the polyps had disappeared after discontinuing PPIs.

Disappearance of Gastric Hyperplastic Polyps after the Discontinuation of Proton Pump Inhibitor in a Patient with Liver Cirrhosis

Here, we report on a rare case of gastric hyperplastic polyps which disappeared after the discontinuation of proton pump inhibitor (PPI). The patient was an 83-year-old woman with liver cirrhosis and portal hypertension, along with gastroesophageal reflux disease treated by PPI. An initial upper gastrointestinal endoscopy showed unique polypoid lesions in the greater curvature of the stomach. Biopsy specimens of the lesions were diagnosed as hyperplastic polyps and she was followed. One year later, a second endoscopy showed that the lesions had increased in number and size, and an endoscopic mucosal resection (EMR) was performed for the main polyps. The resected specimens indicated a proliferation of foveolar epithelium cells with an increase of capillary ectasia and parietal cell hyperplasia, which was thought to be induced by hypergastrinemia from the PPI. Three months after the EMR, she was admitted because of bleeding from the remaining polyps along with an increase in new polyps. After conservative treatment, PPI was stopped and rebamipide was used. One year and 6 months later, an endoscopy showed the complete disappearance of all gastric polyps.

Magnetic resonance imaging findings of a myxoid leiomyosarcoma of the uterus: A case report and literature review

Uterine myxoid leiomyosarcomas (MLMSs) are extremely rare. Here, we report a rare case of uterine MLMS with unique and bizarre magnetic resonance imaging (MRI) findings on diffusion-weighted images (DWIs) and dynamic contrast-enhanced (DCE) MRI scans. A 67-year-old woman presented with a uterine MLMS that had a multilocular cystic mass with a septum and solid components. The tumour demonstrated marked hyperintensity on T2-weighted images in a myxoid stroma with gradual partial contrast enhancement and diffusion restriction, which could be a characteristic feature suggestive of a myxoid malignant smooth muscle tumour of the uterus rather than a uterine leiomyoma with myxoid degeneration.

Basedow's disease with associated features of Hashimoto's thyroiditis based on histopathological findings

BACKGROUND

Basedow's disease and Hashimoto's thyroiditis are autoimmune thyroid disorders and usually diagnosed with elevation of serum autoimmune antibodies. Thyrotropin receptor antibodies (TRAb) and/or thyroid-stimulating antibody (TSAb) are usually used for diagnosis of Basedow's disease, and thyroid peroxidase antibodies (TPOAb) and/or thyroglobulin antibodies (TgAb) are for diagnosis of Hashimoto's thyroiditis. However, it is difficult to diagnose a subject as Basedow's disease with associated features of Hashimoto's thyroiditis only with elevation of such autoimmune antibodies.

CASE PRESENTATION

A 44-year-old woman with 5-year history of Basedow's disease underwent a total thyroidectomy. She did not have a goiter. TRAb, TSAb, TPOAg and TgAb were all positive before a total thyroidectomy. In histopathological macroscopic examination, diffuse hyperplasia of the thyroid gland was observed. Furthermore, in histopathological microscopic examination, both characteristics of Basedow's disease and Hashimoto's thyroiditis were observed. After a total thyroidectomy, titers of all thyroid-associated autoimmune antibodies were markedly reduced.

CONCLUSION

Herein, we report a subject with Basedow's disease without a goiter whose TPOAb and TgAb were relatively high at the onset of Basedow's disease. In addition, interestingly, the histopathological findings of this subject showed direct signs of Basedow's disease and Hashimoto's thyroiditis in the same thyroid gland. Considering from such findings, she seemed to have Basedow's disease with associated features of Hashimoto's thyroiditis. In conclusion, we should bear in mind the possibility of Basedow's disease with associated features of Hashimoto's thyroiditis in subjects with Basedow's disease, particularly when TPOAb and TgAb as well as TRAb and TSAb are positive.

High Prevalence of Autoimmune Gastritis in Patients with Nonalcoholic Steatohepatitis

Objective To evaluate the prevalence of autoimmune gastritis in patients with histologically proven nonalcoholic steatohepatitis (NASH). Methods A total of 33 patients with NASH and 143 patients with chronic liver disease (66, 24, 22, 10, 1, and 21 patients with hepatitis C, hepatitis B, autoimmune hepatitis/primary biliary cholangitis, non-B/non-C hepatitis, fatty liver, and alcoholic disease, respectively) who underwent upper gastrointestinal endoscopy between January 2013 and August 2016 were retrospectively assessed to determine the prevalence of autoimmune gastritis. The clinical characteristics of these patients with NASH and autoimmune gastritis were examined, and the clinical characteristic and biomarkers were compared between patients with NASH with and without autoimmune gastritis. Results Six of the 33 patients with NASH (19.4%) were diagnosed with autoimmune gastritis. The prevalence of autoimmune gastritis was higher in patients with NASH than in those with other chronic liver diseases [4/143 (2.8%), p=0.002]. All six patients with NASH and autoimmune gastritis exhibited high serum gastrin levels; five of the patients were positive for anti-parietal cell antibodies, and one was negative for anti-parietal cell antibodies but positive for intrinsic factor antibody. Furthermore, 1 patient presented with iron-deficiency anemia (hemoglobin <11 g/dL), but none developed pernicious anemia. Endocrine cell micronests were found in four patients. Patients with NASH and autoimmune gastritis tended to be older with lower ferritin levels than the other patients. Conclusion The prevalence of NASH with concomitant autoimmune gastritis was high, highlighting the need for upper endoscopy for the diagnosis of autoimmune gastritis and gastric malignancies.

A case report of left lower lobe segmentectomy for pulmonary metastasis from retroperitoneal liposarcoma

BACKGROUND

The principle treatment for retroperitoneal liposarcoma is surgical resection, however there are many cases of recurrence. In addition to local recurrence, retroperitoneal liposarcoma, particularly dedifferentiated liposarcoma is known to occasionally cause lung metastases.

CASE REPORT

A 72-year-old woman with a diagnosis of retroperitoneal liposarcoma and probable right upper lobe early pulmonary adenocarcinoma underwent sequential local tumor resection and right upper lobectomy. Twenty months after liposarcoma resection, a computed tomography (CT) scan of the chest revealed a nodule located in the left lower lobe. A CT-guided biopsy was performed and she was subsequently diagnosed with pulmonary metastasis from retroperitoneal liposarcoma. The nodule enlarged chronologically, however a left lower lobectomy could not be performed because respiratory function after the right upper lobectomy was not sufficient. Therefore, in order to preserve the left superior segment (S6), the basal segments (S8+S9+S10) were resected. Seven months after the surgery, she is living a self-reliant life without recurrence of liposarcoma.

CONCLUSION

Here we have reported a case of pulmonary metastasis from retroperitoneal liposarcoma following limited surgery. In cases where respiratory function is limited, lower lobe segmentectomy can be an effective treatment. For the treatment of a single pulmonary metastasis from retroperitoneal liposarcoma, metastasectomy was considered to be effective as long as no local recurrence was seen after initial primary tumor resection.

Descending necrotizing mediastinitis in a healthy young adult

A 26-year-old man with right lower mandibular and chest pain, fever, and respiratory distress was urgently transported to our hospital. CT images revealed gas collection and an abscess from the neck to the mediastinum with bilateral pleural effusion. Descending necrotizing mediastinitis (DNM) induced by an odontogenic infection of a right mandibular molar abscess was diagnosed. The cervical and mediastinal areas were drained, extensive debridement was performed, necrotic tissue was excised, and broad-spectrum antibiotics were administered immediately. Prompt diagnosis and intensive care were necessary for managing the DNM, and the patient was discharged with no comorbidities.

A Case of Birt-Hogg-Dubé (BHD) Syndrome Harboring a Novel Folliculin (FLCN) Gene Mutation

Patient: Female, 56

Final Diagnosis: Birt-Hogg-Dubé syndrome

Symptoms: Dyspnea

Medication: —

Clinical Procedure: —

Specialty: Pulmonology

Herpetic esophagitis following bendamustine-containing regimen

A 76-year-old Japanese woman presented to our hospital with anorexia. Two years before, she was diagnosed with non-Hodgkin's lymphoma and had received ten cycles of systemic chemotherapy. After salvage chemotherapy with bendamustine and rituximab (B-R), bone marrow suppression had lasted >3 months. Esophagogastroscopy revealed polynesic white protrusions in the mid-esophagus. These lesions were diagnosed as herpetic esophagitis. To the best of our knowledge, there is no other report in which herpetic esophagitis has been documented as an adverse event of B-R regimen. Because the complication could cause symptomatic gastrointestinal discomfort, physicians should be aware of this disease.

Successful palliation for an aged patient with primary pericardial mesothelioma

An 85-year-old Japanese man with a complaint of exertional dyspnea was admitted to our hospital. Sixty-three years prior to admission at our hospital, he handled asbestos for 2 years in a factory. His chest computed tomography showed a massive pericardial effusion leading to cardiac tamponade and right pleural plaque. After a pericardiocentesis was performed, he recovered from cardiac failure caused by the cardiac tamponade. Pathological examination of the pericardial effusion revealed malignant mesothelial cells. Therefore, he was diagnosed with primary pericardial mesothelioma (PPM) related to asbestos exposure. Although his disease slowly progressed over 18 months, he remained active without any adjuvant treatments such as chemotherapy. Long-term palliation in an aged patient with PPM is rarely obtained using supportive care alone because the prognosis of PPM has been consistently reported to be very poor and almost fatal within a year. Clinical oncologists and thoracic surgeons should be aware of this disease because the accumulation of knowledge on PPM may lead to successful treatment even in aged patients.

Non-occlusive mesenteric ischemia after splenic metastasectomy for small-cell lung cancer

A 68-year-old man presented with severe abdominal pain. Seven months earlier, he had received systemic chemotherapy for small-cell lung cancer with solitary metastasis to the spleen, followed by splenectomy. Abdominal computed tomography and abdominal arterial angiography showed diffuse ischemia of the mesenteric artery without apparent occlusion. The patient also suffered from septicemia caused by Enterococcus faecium. Therefore, a diagnosis of non-occlusive mesenteric ischemia (NOMI) induced by septicemia was supposed. Although treatment with antibiotics and papaverine hydrochloride was administered and the necrotic tissue in the intestinal tract was resected, the patient died. Physicians should be aware that patients undergoing splenectomy are likely to be affected by septicemia, which may subsequently induce NOMI.

Obstructive jaundice caused by intraductal metastasis of lung adenocarcinoma

Obstructive jaundice caused by metastases to the porta hepatis is often observed in patients with various advanced cancers; however, metastasis of lung cancer to the common bile duct with subsequent development of jaundice is rare. A 75-year-old female with lung adenocarcinoma harboring epidermal growth factor receptor (EGFR) mutation (15-bp in-frame deletion in exon 19 and T790M in exon 20) developed obstructive jaundice during therapy. Obstruction of the common bile duct caused by an intraductal tumor was identified by computed tomography, endoscopic retrograde cholangiopancreatography, and endoscopic ultrasonography. Although primary cholangiocarcinoma was highly suspected according to the imaging findings, immunohistochemical evaluation of the intraductal tumor demonstrated thyroid transcription factor-1 positive adenocarcinoma. Furthermore, peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp analysis showed that the tumor contained the same EGFR mutation as that in the primary lung cancer. Thus, we confirmed intraductal metastasis from a lung adenocarcinoma. To our knowledge, this is the second report of obstructive jaundice caused by intraductal metastasis of lung cancer.

Docetaxel for non-small-cell lung cancer harboring the activated EGFR mutation with T790M at initial presentation

A 72-year-old woman was referred to our hospital with Stage IV non-small-cell lung cancer (NSCLC). Chest computed tomography revealed a mass in the upper lobe of the right lung, with pleural effusion. Cytologic examination identified adenocarcinoma cells in the right pleural effusion. Furthermore, both a deletion mutation in exon 19 and a threonine-methionine substitution mutation at position 790 in exon 20 (T790M) were detected in the epidermal growth factor receptors (EGFR) in the malignant cells. As systemic chemotherapy consisting of carboplatin and pemetrexed or erlotinib proved ineffective, docetaxel monotherapy was initiated as a third-line treatment. Following salvage chemotherapy, her Eastern Cooperative Oncology Group performance status improved from 3 to 1, with tumor regression over 5 months. To the best of our knowledge, this is the first report of successful docetaxel treatment for a patient with NSCLC harboring the T790M EGFR-activating mutation identified before treatment with EGFR tyrosine kinase inhibitors.