Clinicopathological features of immunoglobulin G4-related constrictive pericarditis.

AIM: Constrictive pericarditis (CP) is characterised by scarring fibrosis and a loss of pericardial elasticity, which causes heart failure. IgG4 (immunoglobulin G4)-related disease (IgG4-RD) is a systemic fibro-inflammatory disease characterised by the infiltration of IgG4-immunopositive plasmacytes and high serum IgG4 levels that frequently shape tumorous lesions. Although pericardial involvement of IgG4-RD is rare, with indications of CP, pericardial effusion and irregular masses, the clinical and pathological features remain unclear. In this study, we examined the relationship between CP and IgG4-RD. METHODS: Among 35 thick-walled CP cases (histologically pericardial thickening ≥2 mm), eight cases were aetiology identified. Using the diagnostic criteria for IgG4-RD, 11 cases were classified as IgG4-CP, whereas the remainder were considered true idiopathic CP (16 cases) and the clinical pathological features were evaluated. RESULTS: Compared with the other groups, the IgG4-CP group was more common in men and associated with low-grade fever and massive pericardial effusion with frequent recurrence. Deaths resulting from heart failure occurred in a few cases of the IgG4-CP group, but not in other groups. An increase in C-reactive protein and a high positivity rate of anti-nuclear antibodies frequently occurred in the IgG4-CP group. Histologically, the IgG4-CP group included lymphoid follicle, eosinophil infiltration and few calcifications. CONCLUSIONS: Pericardial IgG4-RD occurs not only as nodular lesions, but also as thick-walled CP, and accounts for approximately 40% of thick-walled CP cases of unknown cause. The predominant clinical characteristic was refractory and recurrent pericardial effusion. Recognising IgG4-RD as a cause of CP is important to initiate appropriate therapy.

Effect of Recent Antirheumatic Drug on Features of Rheumatoid Arthritis-Associated Lymphoproliferative Disorders.

OBJECTIVE: In this study, we examine how advancements in novel antirheumatic drugs affect the clinicopathologic features of lymphoproliferative disorder (LPD) in patients with rheumatoid arthritis (RA). METHODS: In this multicenter study across 53 hospitals in Japan, we characterized patients with RA who developed LPDs and visited the hospitals between January 1999 and March 2021. The statistical tools used included Fisher's exact test, the Mann-Whitney U-test, the log-rank test, logistic regression analysis, and Cox proportional hazards models. RESULTS: Overall, 752 patients with RA-associated LPD (RA-LPD) and 770 with sporadic LPD were included in the study. We observed significant differences in the clinicopathologic features between patients with RA-LPD and those with sporadic LPD. Histopathological analysis revealed a high frequency of LPD-associated immunosuppressive conditions. Furthermore, patients with RA-LPD were evaluated based on the antirheumatic drugs administered. The methotrexate (MTX) plus tacrolimus and MTX plus tumor necrosis factor inhibitor (TNFi) groups had different affected site frequencies and histologic subtypes than the MTX-only group. Moreover, MTX and TNFi may synergistically affect susceptibility to Epstein-Barr virus infection. In case of antirheumatic drugs administered after LPD onset, tocilizumab (TCZ)-only therapy was associated with lower frequency of regrowth after spontaneous regression than other regimens. CONCLUSION: Antirheumatic drugs administered before LPD onset may influence the clinicopathologic features of RA-LPD, with patterns changing over time. Furthermore, TCZ-only regimens are recommended after LPD onset.

Dual blockade of MET and VEGFR2 signaling pathways as a potential therapeutic maneuver for peritoneal carcinomatosis in scirrhous gastric cancer.

Scirrhous gastric cancer frequently develops into peritoneal carcinomatosis with malignant ascites, leading to an extremely poor prognosis. We had demonstrated that paracrine hepatocyte growth factor (HGF)-induced MET activation promotes peritoneal carcinomatosis with ascites formation. The vascular endothelial growth factor (VEGF) receptor (VEGFR)/VEGF axis facilitates tumor progression and formation of malignant ascites. This study investigated the role of MET and VEGFR2 in the development of peritoneal carcinomatosis with malignant ascites. Cabozantinib is a dual inhibitor of MET and VEGFR2. We examined the effects of cabozantinib on MET- and VEGFR2-mediated progression of peritoneal carcinomatosis in human scirrhous gastric cancer in vitro and in vivo. Cabozantinib inhibited HGF-stimulated proliferation of scirrhous cancer cell lines NUGC4 and GCIY, with a high potential to generate peritoneal carcinomatosis with ascites fluid, as well as the constitutive proliferation of MKN45 cells with MET amplification. Cabozantinib also inhibited the phosphorylation of both MET and VEGFR2 in scirrhous cancer cells and HGF- or VEGF-stimulated HUVECs. It effectively reduced ascitic fluid and prolonged the survival of NUGC4-inoculated nude mice. In clinical specimens, malignant ascites fluid from patients with peritoneal carcinomatosis contained high levels of HGF and VEGF. Our results strongly suggest that MET- and VEGFR2-mediated signaling pathways play pivotal roles in the pathogenesis of peritoneal carcinomatosis in scirrhous gastric cancer. Thus, the dual blockade of MET and VEGFR2 signaling may be a potential therapeutic maneuver for peritoneal carcinomatosis in scirrhous gastric cancer.

Concordance of the histological diagnosis of type 1 autoimmune pancreatitis and its distinction from pancreatic ductal adenocarcinoma with endoscopic ultrasound-guided fine needle biopsy specimens: an interobserver agreement study.

The histological diagnosis of type 1 autoimmune pancreatitis (AIP) based on the findings obtained by an endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is feasible, but the diagnostic consistency of this method has not been confirmed. We determined the interobserver agreement among 20 pathologists regarding the diagnosis of type 1 AIP, including the distinction from pancreatic ductal adenocarcinoma (PDAC) using large tissue samples obtained by EUS-FNB. After guidance for diagnosing AIP with biopsy tissues was provided, a round 2 was performed. The median sensitivity and specificity for diagnosing PDAC vs. non-neoplastic diseases were 95.2% and 100%, respectively. In groups of specialists (n = 7) and the generalists (n = 13), Fleiss' к-values increased from 0.886 to 0.958 and from 0.750 to 0.816 in round 2. The concordance was fair or moderate for obliterative phlebitis and storiform fibrosis but slight for ductal lesion of type 1 AIP. Discordant results were due to ambiguous findings and biopsy tissue limitations. Among the specialists, the ratio of cases with perfect agreement regarding the presence of storiform fibrosis increased in round 2, but agreement regarding obliterative phlebitis or ductal lesions was not improved. Although the histological definite diagnosis of type 1 AIP was achieved by most observers in > 60% of the cases, the confidence levels varied. Because some ambiguities exist, the histological diagnostic levels based on the diagnostic criteria of type 1 AIP should not be taken for granted. Guidance is effective for improving accurate PDAC diagnoses (notably by recognizing acinar-ductal metaplasia) and for evaluating storiform fibrosis.

Regional disturbance of the distribution of T regulatory cells and T helper cells associated with irregular-shaped germinal centers in immunoglobulin G4-related sialadenitis.

Although many germinal centers (GCs) have been reported in immunoglobulin (Ig) G4-related disease, the significance of GCs in IgG4-related disease has not received attention. Both T follicular regulatory cells (Tfr), which are regulatory T cells (Treg) in GCs, and T follicular helper cells (Tfh) produce the cytokine interleukin (IL)-10 and regulate GC development. In whole-slide image analysis in surgical specimens using immunohistochemistry, IgG4-related sclerosing sialadenitis (IgG4-SS, n = 17) was characterized by markedly numerous, large, and irregular-shaped GCs with increased IL-10 + cells and Tfr and Tfh in the total area of the salivary gland compared with controls, including patients with chronic sialadenitis (n = 17) and Sjögren syndrome (n = 15). In particular, the central area of GC in IgG4-SS showed a higher Tfr number and Tfr/Tfh ratio than controls. The number of Tfr in the central area was significantly correlated with the number of IgG4 + plasmacytes and the number, size, and irregularity of GCs. In the mantle area, which surrounds GCs, IgG4-SS showed a higher Treg number and Treg/T helper cells (Th) ratio than controls. In IgG4-SS, the Treg/Th ratio was highest in the mantle area outside GCs and the Tfr/Tfh ratio was highest in the central area inside GCs. However, in controls, the Treg/Th ratio gradually decreased from outside to inside GCs. Our findings reveal that the morphological abnormality of GCs and the characteristic localization and altered balance of Treg and Th in the different compartments of inside and outside GCs would be the novel hallmarks of IgG4-SS.

Suitability of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration versus Paired Transbronchial Biopsy Specimens for Evaluating Programmed Death Ligand-1 Expression in Stage III and IV Lung Cancer: A Comparative Retrospective Study.

Objectives: Cancer cells usually escape tumor-reactive T-cell responses using immune checkpoint proteins, such as programmed death protein-1 (PD-1) and its ligand, programmed death ligand-1 (PD-L1). These proteins can be blocked by immune checkpoint inhibitors (ICIs); the decision on ICI-based first-line treatment for advanced lung cancers depends on the PD-L1 levels in tumor specimens. Determining the PD-L1 expression conventionally requires histological specimens from resected tumors and core biopsy specimens. Non-small cell lung cancer (NSCLC) is usually diagnosed at stage III or IV; therefore, only small biopsy specimens, such as those obtained via endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are available. However, the suitability of EBUS-TBNA specimens determining the PD-L1 expression levels in advanced lung cancers remains unclear. Materials and Methods: Here, we investigated the concordance rate of PD-L1 expression between EBUS-TBNA and matched transbronchial biopsy (TBB) specimens. Using the 22C3 anti-PD-L1 antibody (immunohistochemistry), we determined the PD-L1 expression levels in paired specimens obtained from 69 patients (50 with advanced NSCLC and 19 with small cell lung cancer [SCLC]), as well as the efficacy of ICIs in these patients. Results: The concordance rate of PD-L1 expression between the EBUS-TBNA and TBB specimens was 78.3%. The κ values referent to the PD-L1-positive expression rate between EBUS-TBNA and TBB specimens were 0.707 and 0.676 at cutoff limits of ≥1% and ≥50%, respectively. Among the 19 SCLC patients, 16 (84.2%) exhibited no PD-L1 expression in both EBUS-TBNA and TBB specimens. Notably, the progression-free survival of patients with ≥50% PD-L1 expression in the paired specimens who received ICI treatment was 8.3 months. Conclusion: Collectively, our results validate the use of EBUS-TBNA specimens for the determination of the PD-L1 expression levels in the context of NSCLC and SCLC.

[Immunoglobulin G4( IgG4)-related Fibrosing Mediastinitis Localized in the Retrosternal Area:Report of a Case].

An 84-year-old man was referred to our out-patient clinic with an elongated mass localized to the retrosternal area that was incidentally identified by computed tomography. On 18F-fluorodeoxyglucose-positron emission tomography, this lesion showed intense tracer uptake. Thus, a surgical biopsy under thoracoscopy was performed. Histological examination revealed dense fibrous tissue associated with inflammatory cell infiltration. The immunoglobulin (Ig) G4/IgG plasma cell ratio was over 90%. Serum IgG4 levels were normal. According to the Umehara criteria for IgG4-related disease, a final diagnosis of a "possible" IgG4-related fibrosing mediastinitis was made. Oral glucocorticoid treatment with 30 mg/day prednisolone reduced the mass.

[Case report of a patient with recurrence after endoscopic submucosal dissection for superficial esophageal cancer, diagnosed with mediastinal lymph node endoscopic ultrasound-fine needle aspiration based on the symptom of hoarseness].

The patient was an 81-year-old man who presented with a complaint of hoarseness. When he was 80 years old, he had developed superficial esophageal cancer and had undergone endoscopic submucosal dissection (ESD) at our hospital. Two months after the ESD, he developed hoarseness. Computed tomography (CT) scan showed no abnormal findings at that time;therefore, he was diagnosed with idiopathic vocal cord paralysis, and followed up with symptom treatment in the Gastroenterology and Otolaryngology Departments. Ten months after the ESD, a CT scan revealed mediastinal lymph node swelling. He was admitted to our hospital for histopathological examination of the lymph node using endoscopic ultrasound-fine needle aspiration (EUS-FNA). The histopathological examination revealed squamous cell carcinoma of the lymph node, similar to the primary esophageal tumor. This result suggests that laryngeal nerve paralysis involving hoarseness is caused by lymph node metastasis of superficial esophageal cancer. We report that histopathological examination with EUS-FNA helps in determining the cause of hoarseness that develops after ESD.

A Case of Duodenal Neuroendocrine Tumor Accompanied by Gastrointestinal Stromal Tumors in Type 1 Neurofibromatosis Complicated by Life-Threatening Vascular Lesions.

BACKGROUND Type 1 neurofibromatosis (NF1) is known to be associated with not only neurogenic tumors but also gastrointestinal (GI) neoplasms. However, there are few reports on vascular lesions and the incidence is unknown. CASE REPORT We report here the case of a 45-year-old woman with a history of NF1 referred to our hospital for the purpose of detailed examination for positive fecal occult blood test. On the basis of the investigation reports, she was diagnosed with a neuroendocrine tumor (NET)-G1. We planned a subtotal stomach-preserving pancreaticoduodenectomy. The abdominal structures, including the vascular system, were abnormally fragile, and it was very difficult to achieve satisfactory hemostasis. The total amount of intraoperative blood loss was 7580 mL. Fulminant intra-abdominal bleeding occurred on postoperative day (POD) 3. Urgent angiography showed a rupture of the gastroduodenal artery. Transarterial embolization was performed, but the patient died of multiorgan failure on POD5. On histological examination, neurofibroma cells proliferating into the surrounding blood vessels were seen; moreover, immunohistochemistry staining with S-100 antibody showed positive neurofibroma cells surrounding the vascular wall. The pathological diagnosis was duodenal NET-G1 with multinodal involvement. CONCLUSIONS This case is a rare presentation of a NET with multiple gastrointestinal stromal tumors associated with NF1, which led to a fatal outcome due to the extreme fragility of the vessel walls. Since patients with NF1 might have vulnerable vessel walls, adequate surgical preparation for major surgical treatment is necessary.

A case of refractory pouchitis complicated by cytomegalovirus infection requiring administration of ganciclovir and infliximab.

Pouchitis is a frequent complication of surgical treatment of ulcerative colitis (UC), and is typically treated using antimicrobials. If pouchitis is refractory to antimicrobials, screening for complications, such as cytomegalovirus (CMV) infection, is necessary. However, the optimal approach to management of pouchitis complicated by CMV infection is unclear. We report the case of a 41-year-old female patient with UC presenting with pouchitis associated with CMV infection; she had received subtotal colectomy/ileal pouch anal anastomosis (IPAA). She was admitted to hospital with persistent fever, epigastric discomfort, and watery diarrhea despite receiving antibiotics. Laboratory findings showed inflammation and reactivation of CMV infection accompanied by liver injury. The endoscopic findings showed inflammation of the pouch and ileal mucosa on the oral side with extensive and deep punched-out ulcers. Immunohistological staining of biopsy specimens from an ulcerated lesion demonstrated CMV infection. Therefore, we diagnosed the patient with pouchitis complicated by CMV infection. The patient was treated with ganciclovir and infliximab, which resolved her symptoms and led to the disappearance of CMV-positive cells. There has been no recurrence of pouchitis. CMV infection should be considered in patients with UC who develop refractory pouchitis.

Imaging features and pathological evaluation by EUS-FNA enable conservative management in patient of lymphoepithelial cyst of the pancreas: a case report.

Pancreatic lymphoepithelial cysts (LECs) are rare cystic lesions filled with a keratinous substance and lined by squamous epithelium with underlying lymphoid tissue. Because pancreatic LECs are entirely benign, correct preoperative diagnosis is important to avoid unnecessary surgery. However, the imaging features of pancreatic LECs are not specific and preoperative diagnosis has proven difficult. A pancreatic mass was incidentally detected through abdominal ultrasonography in a 63-year-old male presenting without any symptoms. Computed tomography showed an exophytic cystic lesion in the pancreatic head. The lesion had heterogeneous high signal intensity with partial low intensity on T2-weighted magnetic resonance imaging (MRI) and high signal intensity on diffusion MRI. Endoscopic ultrasound (EUS) examination showed an encapsulated cystic lesion with relatively homogenous and highly echoic contents. EUS-guided fine-needle aspiration (EUS-FNA) revealed caseous appearance and rare fragments of apparently benign squamous epithelium on a background of keratinous debris, cyst contents, and scattered lymphocytes. We diagnosed a pancreatic LEC and opted for conservative management without surgery. Pathological evaluation based on images obtained through EUS-FNA showed macro- and microscopic features that were critical to determining the management strategy. In conclusion, the imaging and pathological features of pancreatic LECs can inform preoperative diagnosis, which may enable conservative management.

Guidance for diagnosing autoimmune pancreatitis with biopsy tissues.

The biopsy-based diagnosis of autoimmune pancreatitis (AIP) is difficult but is becoming imperative for pathologists due to the increased amount of endoscopic ultrasound-guided biopsy tissue. To cope with this challenge, we propose guidance for the biopsy diagnosis of type 1 AIP. This guidance is for pathologists and comprises three main parts. The first part includes basic issues on tissue acquisition, staining, and final diagnosis, and is intended for gastroenterologists as well. The second part is a practical guide for diagnosing type 1 AIP based on the AIP clinical diagnostic criteria 2018. Inconsistent histological findings, tips for evaluating IgG4 immunostaining and key histological features including the ductal lesion and others are explained. Storiform fibrosis and obliterative phlebitis are diagnostic hallmarks but are sometimes equivocal. Storiform fibrosis is defined as spindle-shaped cells, inflammatory cells and fine collagen fibers forming a flowing arrangement. Obliterative phlebitis is defined as fibrous venous obliteration with inflammatory cells. Examples of each are provided. The third part describes the differentiation of AIP from pancreatic ductal adenocarcinoma (PDAC), focusing on histological features of acinar-ductal metaplasia in AIP, which is an important mimicker of PDAC. This guidance will help standardize pathology reports of pancreatic biopsies for diagnosing type 1 AIP.

[Thymoma Presenting Synchronously with a Mycosis Fungoides;Report of a Case].

A 65-year-old woman presented with mycosis fungoides and an anterior mediastinal tumor. Stage Ⅱa mycosis fungoides was treated with bath psoralen plus ultraviolet A, topical corticosteroids, and oral bexarotene. One month later, a surgical resection was performed for the anterior mediastinal tumor, which was a stage Ⅱ thymoma with membrane invasion. Furthermore, adjuvant radiotherapy was performed for anterior mediastinum. The mycosis fungoides lesion exacerbated after 3 months;thus, chemotherapies were performed. The patient died of respiratory insufficiency due to multiple pulmonary metastases of mycosis fungoides 1 year after the operation.

The Serum Mac-2-binding Protein Glycosylation Isomer Dynamics in Acute Liver Injury.

Objective We aimed to examine the dynamics of serum Wisteria floribunda agglutinin-positive human Mac-2-binding protein glycosylation isomer (M2BPGi) in patients with acute liver injury. Methods Serum M2BPGi levels at the time of the diagnosis (n=77) and normalization of the serum alanine aminotransferase (ALT) level (n=26) were examined retrospectively. The difference in the serum M2BPGi level according to the etiology, and the correlations with other laboratory parameters were evaluated. Results The serum M2BPGi level at the time of the diagnosis was increased in 59 of 77 patients [2.3 cutoff index (COI); range, 0.31-11.1 COI] and was significantly decreased at the time of serum ALT normalization (0.68 COI; range, 0.15-1.87 COI; p<0.0001). The serum M2BPGi level was positively correlated with the duration for which serum ALT normalization was achieved (n=46, Spearman rho=0.53, p<0.0001). A multivariate analysis identified total bilirubin (T-bil), albumin, ALT, alkaline phosphatase, and etiology (e.g., drug-induced liver injury or etiology unknown) as independent factors for increased serum M2BPGi. In patients with infectious mononucleosis, the serum M2BPGi level was higher relative to the degree of increase of serum ALT or T-bil levels in comparison to other etiologies. Conclusion The serum M2BPGi level in patients with acute liver injury reflects the magnitude and duration of liver injury. However, it should be noted that the degree of increase of serum M2BPGi in patients with acute liver injury may differ according to the etiology.

Clinicopathological features of immunoglobulin G4-related pleural lesions and diagnostic utility of pleural effusion cytology.

OBJECTIVE: Immunoglobulin (Ig)G4-related disease is a recently described systemic immune-mediated fibro-inflammatory disease that frequently occurs in tumorous form. Herein, we elucidated the clinicopathological and cytological characteristics of IgG4-related pleural lesions (PLs). PATIENTS AND METHODS: Among 22 patients with fibro-inflammatory PLs of idiopathic aetiology, eight cases were diagnosed as IgG4-PL and the remaining 14 as non-IgG4-PL according to comprehensive diagnostic criteria for IgG4-related disease. Cell block examination of pleural effusion (CBPE) was performed in five patients with IgG4-PL and in six with non-IgG4-PL. Both groups were compared in terms of clinical presentation, laboratory data, histopathological features of resected pleura, and cytological features of pleural effusion (PE). RESULTS: PE was the most common (six patients, 75%) clinical presentation of IgG4-PL. IgG4-PL comparatively showed significantly more frequent concomitant allergic disease (P = .021), higher serum IgE levels (P = .012), higher adenosine deaminase levels in pleural fluid (P = .005), and rare spontaneous recovery without treatment (P = .046). The IgG4-PL group was histologically characterised by thicker fibrous pleura, storiform fibrosis, and infiltration of regulatory T cells, eosinophils and basophils. Using CBPE, IgG4-PL was cytologically distinct with numerous IgG4+ cells and eosinophils. The cytology of CBPE positively correlated with the histology of pleural tissue in the number of IgG4+ cells and eosinophils (R = .769 and .803, respectively). CONCLUSION: IgG4-PL frequently presents with PE and is histologically and cytologically characterised by abundant infiltration of IgG4+ cells and eosinophils. We believe that CBPE with immunohistochemistry/special staining could assist in the auxiliary diagnosis of IgG4-PL.

Recurrent biliary dissemination of colon cancer liver metastasis: a case report.

BACKGROUND: Most colorectal cancer liver metastases form nodules within the hepatic parenchyma, and hepatectomy is the only radical treatment for synchronous metastases. There is concern about intrabiliary tumor growth which may affect the surgical margin, resulting in local recurrence after hepatectomy for colorectal cancer liver metastasis; however, there has been no report of the dissemination in the bile duct after hepatectomy. Here, we report an unusual case of biliary dissemination of colorectal cancer that caused recurrent intrabiliary growth after hepatectomy, and discuss the management of intrabiliary metastasis of colorectal cancer. CASE PRESENTATION: A 69-year-old Japanese man underwent treatment for liver dysfunctions 3 years after aortic valve replacement. Computed tomography revealed an enhanced tumor within the hilar bile duct and dilatation of the left hepatic duct, typical of hilar cholangiocarcinoma. Endoscopic retrograde cholangiopancreatography revealed tumor shadow in his bile duct, and the cytology confirmed malignant cells in the bile. We performed extended left hepatectomy with bile duct resection; his postoperative course remained good without acute complications. After 3 months postoperatively, he was readmitted for subacute cholangitis and obstructive jaundice. Immediately, percutaneous transhepatic cholangiography drainage was performed, followed by cholangiography that exhibited intrabiliary tumor growth in the remnant liver. On immunohistochemical examination, tumor cells were positive for cytokeratin 20 and CDX2 but negative for cytokeratin 7. Then, computed tomography revealed an enhanced tumor-like lesion at the descending colon. After 3 months, left hemicolectomy was performed. Meanwhile, the percutaneous transhepatic cholangiography drainage fluid turned bloody, which was considered to be bleeding from a residual bile duct tumor. Accordingly, radiotherapy was initiated to prevent tumor bleeding around the hilar bile duct, but, unfortunately, the effects were short-lived, and cholangitis rebooted after 1 month leading to our patient's death due to septic liver failure. Autopsy revealed a remnant tumor in the bile duct, but no noticeable nodular metastasis was observed, except for a single small metastasis in the lower lobe of the left lung. CONCLUSIONS: The intrabiliary growth of metastatic colorectal cancer mimics cholangiocarcinoma occasionally. To date, as the effect of chemotherapy or radiotherapy remains uncertain, the complete resection of a bile duct tumor is the only method which could result in a better prognosis.

IgG4-Related Pleuritis With No Other Organ Involvement.

A 65-year-old man was admitted for productive cough and dyspnea. Bilateral pleural effusions were observed on chest X-ray. Although the bilateral pleural effusions were exudative with an increased number of lymphocytes, bacterial culture and polymerase chain reaction analysis for Mycobacterium tuberculosis were negative. Immunological examinations showed high levels of immunoglobulin G4 (IgG4) in both serum and pleural effusion fluid. Pathologic evaluation of a left pleural biopsy specimen using hematoxylin and eosin staining and immunohistochemical staining showed fibrosis-associated lymphoplasmacytic infiltration, 50 IgG4-positive plasma cells per high-power field, and an IgG4/IgG ratio of 40%. Thus, a diagnosis of IgG4-related pleuritis without other systemic manifestations was established. The bilateral pleural effusion improved following corticosteroid therapy. This is a rare case of IgG4-related pleuritis with no other organ involvement.

Inflammatory features, including symptoms, increased serum interleukin-6, and C-reactive protein, in IgG4-related vascular diseases.

Immunoglobulin (IgG) 4-related diseases (IgG4-RDs) are fibro-inflammatory conditions characterized by tumorous swelling and serum IgG4 levels. Intrapelvic IgG4-RD has been subclassified according to the localization site and aortic shape as IgG4-related aortic aneurysms (IgG4-AAs), periaortitis (IgG4-PA), and retroperitoneal fibrosis (IgG4-RF). The IgG4-AA pathogenesis would involve interleukin (IL)-6 upregulation, and Th2-predominant and Treg-activated immune conditions. We characterized the features of intrapelvic IgG4-RD lesions, including presence of vascular lesions. The clinical, serological, and pathological features, including cytokines concerning Th1/2 and Treg (IL-4, IL-6, IL-10, IL-13, and interferon-gamma) of patients with IgG4-AAs (n = 24), IgG4-PA (n = 8), and IgG4-RF (n = 10) were retrospectively compared. Clinical symptoms, such as low-grade fever, abdominal/lumber pain, and anemia, were frequently detected in IgG4-AAs but rarely in IgG4-RF. Serum IL-6 and C-reactive protein (CRP) were significantly higher in IgG4-AAs and IgG4-PA than in IgG4-RF. Pathologically, IL-6+ cells were more frequently detected in IgG4-PA and IgG4-AAs than in IgG4-RF. There were no noteworthy differences in the clinical complications, white blood cell counts, serum IgE, and serum and immunopositive cells of other cytokines between the subgroups. Among IgG4-AAs and IgG4-PA, serum IL-6 and IL-6+ cells correlated with CRP, aortic diameter, and periaortic fibrosis. IgG4-AA and IgG4-PA, but not IgG4-RF, were characterized by "inflammatory" features, such as increased CRP and serum/pathological IL-6, and clinical inflammatory symptoms; thus, IgG4-AA and IgG4-PA belong to the same group as IgG4-related vascular disease. High levels of CRP and IL-6 would be hallmarks of IgG4-related vascular disease.

A Young Man with Non-alcoholic Steatohepatitis and Serum Anti-mitochondrial Antibody Positivity.

A 37-year-old obese man who was a social drinker was admitted to our hospital to undergo a detailed examination for liver injury with anti-mitochondrial antibody positivity. Abdominal ultrasonography revealed moderate fatty liver. A histological analysis showed steatosis of approximately 30% of the hepatocytes, focal necrosis, a few ballooning hepatocytes and lobular inflammation suggestive of steatohepatitis, epithelioid granuloma and irregularity of the sequence of the bile duct epithelium accompanied by lymphocyte infiltration suggestive of chronic cholangitis. He was diagnosed with non-alcoholic steatohepatitis complicated with primary biliary cholangitis. His liver injury was improved by weight loss and high-dose ursodeoxycholic acid treatment.

A case of an elderly female with diffuse hepatic hemangiomatosis complicated with multiple organic dysfunction and Kasabach-Merritt syndrome.

Since diffuse hepatic hemangiomatosis (DHH) is an extremely rare disease especially in adults, the etiology and natural course of adult-onset DHH has not been well understood. We report a case of DHH complicated with multiple organic dysfunction and Kasabach-Merritt syndrome (KMS) in an 83-year-old female. She presented with mild abdominal distension and laboratory findings revealed thrombocytopenia and abnormal coagulation, indicating disseminated intravascular coagulation (DIC). Enhanced computed tomography revealed diffuse, hypodense hepatic nodules with delayed enhancement involving the whole liver, and multiple hypodense splenic legions. To obtain a definitive diagnosis, laparoscopic-guided biopsy was performed. Histological findings revealed irregularly dilated non-anastomotic vascular spaces, which were lined with flat endothelial cells without cellular atypia. We diagnosed this as DHH complicated with splenic lesions and KMS. Although the patient was treated with symptomatic treatment, such as anti-coagulation therapy, hemangiomatous lesions, especially in the spleen, progressed rapidly, leading to worsening of DIC. Finally, the patient died of multiple organ failure at 12 months after diagnosis. A postmortem examination demonstrated diffuse hemangiomatosis of not only the liver and spleen, but also the adrenal glands and bone marrow. Despite no malignant histologically, DHH can be fatal if it progresses rapidly within a short period of time.