Pathogenesis of follicular thymic hyperplasia associated with rheumatoid arthritis.

Lymphoproliferative disorders may occur in patients with rheumatoid arthritis (RA) who are treated with methotrexate. However, follicular thymic hyperplasia (FTH) associated with RA (FTH-RA) is generally not considered a lymphoproliferative disorder. To investigate the pathogenesis of FTH-RA, we examined 12 cases of FTH involving thymic enlargement, four of FTH involving RA and eight of FTH involving myasthenia gravis (MG). Increased numbers and larger germinal center (GC) size were observed in FTH-RA group. The percentage of distorted GCs was 13.3% in FTH-RA group and 3.25% in FTH associated with MG (FTH-MG) group. A greater meshwork of follicular dendritic cells was observed in the GCs of FTH-RA group. Positive indices of CD27+ cells and PD-1+ cells per GC in FTH-RA group were significantly higher than those in FTH-MG group, though positive indices of CD68+ cells and CD163+ cells were similar. Myoid cell proliferation, as evaluated by α-SMA, tenascin-C, and l-caldesmon expression, was significantly increased in the FTH-RA group compared with the FTH-MG group. These results suggest that FTH should be considered in patients with RA treated with methotrexate. The pathogenesis of FTH-RA includes GC expansion and increased numbers of memory B cells, follicular helper T cells, and myoid cells, indicating humoral immunity activation.

Comparative study of HO-1 expressing synovial lining cells between RA and OA.

OBJECTIVES: We aimed to clarify the characteristics of heme oxygenase (HO)-1 expressing cells in the synovium from rheumatoid arthritis (RA) and osteoarthritis (OA), and to investigate the co-expression of HO-1 and IgG-Fc/HLA-DR complex. METHODS: The characteristics of HO-1 expressing cells in the synovium were investigated by using immunohistochemistry. The co-expression of HO-1 and IgG-Fc/HLA-DR complex was examined by an in situ proximity ligation assay (PLA) with immunofluorescence. HO-1 mRNA was investigated by reverse transcription-polymerase chain reaction. RESULTS: The number of HO-1+ cells from the RA synovium is higher than that from OA synovium. The double positive cells of HO-1 and IgG-Fc/HLA-DR complex were detected by the in situ PLA with immunofluorescence in RA synovium. HO-1 mRNA was detected in both RA and OA synovium. CONCLUSION: A portion of HO-1+ cells with IgG-Fc/HLA-DR complex in lining layer of RA may be concluded as one of antigen presenting cells in RA and may be involved in production of RF.

Good prognosis for follicular lymphoma with estrogen receptor α-positive follicular dendritic cells.

Follicular lymphoma (FL) has a meshwork of follicular dendritic cells (FDCs). We previously demonstrated the presence of estrogen receptor alpha (ERα)+ CD23+ FDCs in grades 1-2 FL. The significance of FDCs as a prognostic factor in FL remains unknown. The current study aimed to compare clinicopathological features, including prognosis, between FL with and without ERα+ FDCs. This study evaluated the clinicopathological significance of ERα expression in 70 FL patients by immunostaining. The presence of ERα mRNA on FDCs from 5 FL patients was confirmed by CD21/ERα double staining (immunohistochemistry and in situ hybridization). We defined patients with frequent ERα expression as the ERαhigh group and those with infrequent ERα expression as the ERαlow group. Thirty-two patients were assigned to the ERαhigh group (45.7%), and 38 patients were assigned to the ERαlow group (54.3%). Both overall survival (OS) and progression-free survival (PFS) were significantly better in the ERαhigh group than in the ERαlow group (OS, log-rank, P = .0465; PFS, log-rank, P = .0336). Moreover, high ERα expression on FDCs was an independent prognostic factor for OS in both the univariate ([hazard ratio] HR, 0.163; P = .0260) and multivariate (HR, 0.050; P = .0188) analyses and for PFS in both the univariate (HR, 0.232; P = .0213) and multivariate (HR, 0.084; P = .0243) analyses. ERα mRNA expression was detected in CD21+ FDCs within the neoplastic follicles of FL patients. In conclusion, a neoplastic follicular microenvironment with ERα-positive FDCs might affect the grade and presence of the follicular pattern of FL and improve patient prognosis.

Immunohistochemical staining as supportive diagnostic tool for pseudomyxoma peritonei arising from intraductal papillary mucinous neoplasm: A report of two cases and literature review.

BACKGROUND/OBJECTIVES: Pseudomyxoma peritonei (PMP) arising from an intraductal papillary mucinous neoplasm of the pancreas (IPMN) is a rare condition. The diagnosis of IPMN as the origin of PMP is mainly inferred from the clinical course and the exclusion of PMP from other organs. The pathological diagnosis has not yet been established. To evaluate the usefulness of immunohistochemical staining for the diagnosis of the primary lesion of PMP as IPMN. METHODS: There are 2 cases of PMP arising from IPMN between March 2010 and December 2019 at National Center for Global Health and Medicine. A PubMed search that reported PMP arising from IPMN identified 16 additional cases. Diagnostic methods and clinicopathological features of 18 cases were compared. RESULTS: Four cases including our two cases used immunohistochemical staining for the diagnosis of PMP arising from IPMN. The correspondence of the immunohistochemical staining between PMP and IPMN was shown in the three cases including previously reported two cases and one of our two cases to identify the primary lesion of PMP as IPMN. In addition, we revealed that the comparison of the immunostaining pattern of PMP with the representative immunostaining pattern of the candidate primary lesions is helpful for the diagnosis of the primary lesion of PMP. CONCLUSIONS: Immunohistochemical staining is helpful to identify the primary lesion of PMP as IPMN.

Relationships between recurrence patterns and subventricular zone involvement or CD133 expression in glioblastoma.

INTRODUCTION: We previously reported that CD133 expression correlated with the recurrence pattern of glioblastoma (GBM). Subventricular zone (SVZ) involvement may also be associated with distant recurrence in GBM. Therefore, we herein investigated whether the combined analysis of SVZ involvement and CD133 expression is useful for predicting the pattern of GBM recurrence. MATERIALS AND METHODS: We retrospectively analyzed 167 cases of GBM. Tumors were divided into four groups based on spatial relationships between contrast-enhanced lesions (CEL) and the SVZ or cortex (Ctx) on MRI. The initial recurrence pattern (local/distant) was obtained from medical records. To identify factors predictive of recurrence, we examined CD133 expression by immunohistochemical, clinical (age, sex, KPS, Ki-67 labeling index, surgery, and MRI characteristics), and genetic (IDH1, MGMT, and BRAF) factors. RESULTS: The CD133 expression rate was higher in SVZ-positive tumors than in SVZ-negative tumors (P = 0.046). Distant recurrence was observed in 21% of patients, and no significant difference was noted in recurrence patterns among the four groups. However, strong CD133 expression was associated with a shorter time to distant recurrence in univariate, multivariate, and propensity-matched scoring analyses (P < 0.0001, P = 0.001, and P = 0.0084, respectively). In the combined analysis, distant recurrence was the most frequent (70%) in group III (SVZ-negative, Ctx-positive) GBM and those with high CD133 expression rates (≥ 15%). CONCLUSION: An integrated analysis of CD133 expression and MRI-based tumor classification may be useful for predicting the recurrence pattern of GBM.

Increasing Heme Oxygenase-1-Expressing Macrophages Indicates a Tendency of Poor Prognosis in Advanced Colorectal Cancer.

BACKGROUND: Many cancers express heme oxygenase-1 -(HO-1) at a higher frequency than healthy tissues, and this elevated expression is associated with cancer prognosis. Here, we aim to clarify the correlation between HO-1-expressing macrophage numbers and clinicopathological parameters of advanced colorectal cancer. MATERIALS AND METHODS: Formalin-fixed and paraffin-embedded tissues of patients with advanced colorectal cancer were used. To detect HO-1 expression in macrophages, immunohistochemistry was performed. The number of positive cells was measured. Furthermore, HO-1 mRNA in colorectal cancer was examined by reverse transcription polymerase chain reaction. RESULTS: Among the HO-1-negative and HO-1-positive groups, 58.02 and 85.00% of cases, respectively, were positive for lymph node metastasis. The disease-free survival (DFS) time was significantly shorter (p < 0.05) in the -HO-1-positive group (2.44 years) than in the HO-1-negative group (4.09 years). However, according to the Cox proportional-hazards regression model, the HO-1-positive group could not be a risk factor of poor prognosis. HO-1 mRNA expression was confirmed in colorectal normal and cancer tissues. CONCLUSION: In this study, the correlation between HO-1-expressing macrophages and clinicopathological parameters in the tumor microenvironment of colorectal cancer was studied for the first time, and the expression was associated with lymph node metastasis and shortening of DFS.

[A case of fibrinogen storage disease with primary biliary cholangitis].

A 66-year-old woman was diagnosed as primary biliary cholangitis (PBC) and was previously hospitalized for ascites and jaundice. She came to our hospital for further examination of the liver by needle biopsy, which showed interface hepatitis that mainly comprised lymphocytes and inflammatory infiltrates in the bile duct in the portal area. On the other hand, numerous intracytoplasmic inclusions that were positive for fibrinogen immunostaining were seen in the lobular area. Finally, we histologically diagnosed as PBC with fibrinogen storage disease (FSD). FSD is rare disease that leads to liver damage caused by abnormal fibrinogen storage in the endoplasmic reticulum of hepatocytes, with only four cases reported in Japan until now.

Differential expression of estrogen receptor-α on follicular dendritic cells from patients with grade 1-2 and grade 3 follicular lymphoma.

Hormone therapy has been used for patients with estrogen receptor alpha (ERα)-positive breast cancers. Recently, some studies reported the expression of ERα on neoplastic cells from B-cell lymphomas. However, there has been only one report of ERα expression on the follicular dendritic cells (FDCs) that structurally and functionally support the microenvironment of follicular lymphomas (FLs). The objective of this study was to investigate the frequency of ERα expression on FDCs in nonneoplastic reactive lymphoid tissues and to compare the frequency of ERα expression on FDCs in the axillary lymph nodes between patients with and without antiestrogen therapy and among patients with grades 1-3 of FL. Reverse transcription-polymerase chain reaction was performed to detect ERα mRNA in FL. In nonneoplastic germinal centers (GCs) from patients with tonsillitis or reactive lymphadenitis, ERα was expressed in the light zone. ERα-positive cells strongly correlated with the width of GCs (rs  = 0.81, P < 0.01) and the CD21-positive (rs  = 0.69, P < 0.01) and CD23-positive (rs  = 0.83, P < 0.01) FDC meshwork. The axillary lymph nodes had fewer ERα-positive cells, smaller GCs, and a looser CD21- and CD23-positive FDC meshwork with hormone therapy than without hormone therapy (P < 0.01). Neoplastic follicles of G1-2 FL had more ERα-positive cells and a larger CD23+ FDC meshwork than those of G3 FL (P < 0.01). ERα mRNA was detected in both G1-2 FL and G3 FL by reverse transcription-polymerase chain reaction. In conclusion, these results suggested that antiestrogen hormone therapy may decrease the number of ERα-positive FDCs and that the responses mediated by the estrogen-ERα interaction on FDCs may differ between G1-2 FL and G3 FL.

[Hypopituitarism associated with autoimmune pancreatitis: a case report].

We herein report the case of a 64-year-old male patient with hypopituitarism associated with autoimmune pancreatitis (AIP). The patient was previously diagnosed with AIP based on the presence of a swollen pancreas, elevated serum immunoglobulin G4, and narrowing of the pancreatic duct by imaging. Magnetic resonance imaging revealed a pituitary stem tumor, and loading test showed a decrease in the function of the anterior lobe suggesting severe failure of growth hormone secretion. Treatment with steroids was effective in reducing the pituitary lesion and improving the function of the anterior lobe. The present case illustrates the importance of pituitary function evaluation before steroid treatment in patients with AIP.

Medium-chain triglycerides supplement therapy with a low-carbohydrate formula can supply energy and enhance ammonia detoxification in the hepatocytes of patients with adult-onset type II citrullinemia.

Citrin, encoded by SLC25A13, constitutes the malate-aspartate shuttle, the main NADH-shuttle in the liver. Citrin deficiency causes neonatal intrahepatic cholestasis (NICCD) and adult-onset type II citrullinemia (CTLN2). Citrin deficiency is predicted to impair hepatic glycolysis and de novo lipogenesis, resulting in hepatic energy deficit. Secondary decrease in hepatic argininosuccinate synthetase (ASS1) expression has been considered a cause of hyperammonemia in CTLN2. We previously reported that medium-chain triglyceride (MCT) supplement therapy with a low-carbohydrate formula was effective in CTLN2 to prevent a relapse of hyperammonemic encephalopathy. We present the therapy for six CTLN2 patients. All the patients' general condition steadily improved and five patients with hyperammonemic encephalopathy recovered from unconsciousness in a few days. Before the treatment, plasma glutamine levels did not increase over the normal range and rather decreased to lower than the normal range in some patients. The treatment promptly decreased the blood ammonia level, which was accompanied by a decrease in plasma citrulline levels and an increase in plasma glutamine levels. These findings indicated that hyperammonemia was not only caused by the impairment of ureagenesis at ASS1 step, but was also associated with an impairment of glutamine synthetase (GS) ammonia-detoxification system in the hepatocytes. There was no decrease in the GS expressing hepatocytes. MCT supplement with a low-carbohydrate formula can supply the energy and/or substrates for ASS1 and GS, and enhance ammonia detoxification in hepatocytes. Histological improvement in the hepatic steatosis and ASS1-expression was also observed in a patient after long-term treatment.

Steroidogenesis in ovarian-like mesenchymal stroma of hepatic and pancreatic mucinous cystic neoplasms.

STEROIDOGENESIS IN HEPATIC MUCINOUS CYSTIC NEOPLASM: Aim Mucinous cystic neoplasms (MCNs) occur in the ovary, pancreas, and retroperitoneum but very rarely in the liver. Mucinous cystic neoplasms are known to harbor ovarian-like mesenchymal stroma (OLS) expressing progesterone and estrogen receptors. In this study we evaluated steroidogenesis in OLS of 25 hepatic MCNs and 24 pancreatic MCNs. Methods Both steroid receptors and steroidogenic factors were immunohistochemically evaluated using H-scores and results were compared with those in 15 ovarian MCNs and 10 normal ovaries. Results Androgen receptor (AR) H-scores in OLS were significantly higher in hepatic, pancreatic, and ovarian MCN than those in normal ovaries. H-scores of cytochrome P450 17α-hydroxylase/c17-20 lyase (P450c17) and 5α-reductase-1 (5αRED-1) in the stroma were significantly higher in OLS of hepatic and pancreatic MCN than in the stroma of ovarian MCN and normal ovary. In tumor epithelium, AR H-scores were significantly higher in hepatic and pancreatic MCN than in ovarian MCN. In both hepatic and pancreatic MCN, a significant positive correlation was detected between AR H-score in the epithelium and P450c17 H-score in OLS (hepatic MCN: Pearson's r = 0.446, P = 0.025; pancreatic MCN: r = 0.432, P = 0.035). In pancreatic MCN, a significantly positive correlation was detected between AR H-score in the tumor epithelium and 5αRED-1 H-score in OLS (Pearson's r = 0.458, P = 0.024). Conclusions These results indicated that locally produced androgens in OLS could be pivotal for tumorigenesis of both hepatic and pancreatic MCN and influence epithelial cells, possibly in a paracrine fashion, which could represent biological significance of OLS in these neoplasms.

Corneal vesicles accumulate collagen VI associated with tissue remodeling in apolipoprotein a-I deficiency: a case report.

BACKGROUND: Apo A-I deficiency clinically shows low serum levels of HDL cholesterol and corneal opacity at a young age. Histopathological evaluations of affected corneas are not enough, and the mechanism of corneal opacity is still unclear. CASE PRESENTATION: A 61-year-old woman suffered from blurred vision with a corneal opacity. She had significantly reduced serum levels of high-density lipoprotein cholesterol and Apo A-I, stenosis of the coronary arteries, and ischemic heart failure. On genetic examination, a homozygous mutation of Apo A-ITsukuba was identified. Histopathological examination of the corneal button after PKP showed numerous vesicles in the corneal stroma, which were more prominent in the deep stroma than in the shallow stroma. Collagen VI was observed in some of those vesicles. CONCLUSION: We experienced a rare case of corneal opacity due to Apo A-I deficiency. Our histopathological findings indicated that structural changes in corneal collagen fibrils contribute to the formation of stromal vesicles.

[Spontaneous Remission of Everolimus-Induced Interstitial Lung Disease in Metastatic Renal Cell Carcinoma : An Autopsy Case Report].

Interstitial lung disease (ILD) is a common side effect of the mechanistic target of rapamycin inhibitor everolimus. Most cases of everolimus-induced ILD are mild and reversible. As per guidelines, even if Common Terminology Criteria for Adverse Events grade 1 or 2 everolimus-induced ILD occurs, either continuation of everolimus without dose reduction or readministration at a low dose is possible. However, the pathophysiology of everolimus-induced ILD is unknown. We present a case of everolimus-induced ILD with spontaneous remission during treatment in a patient with metastatic renal cell carcinoma. At autopsy, there was no evidence of remodeling or chronic inflammation in the lungs. Cryptogenic interstitual pneumonia and broncholitis obliterans with organizing pneumonia can be suspected as a pattern of mild everolimus-induced ILD. This case report provides evidence that everolimus-induced ILD is reversible fromthe pathological perspective.

A case of pancreatic intraepithelial neoplasia-3 with autoimmune pancreatitis.

We report a case of pancreatic intraepithelial neoplasia-3 (PanIN-3) with autoimmune pancreatitis (AIP). The patient, a 75-year-old man, had been diagnosed to have AIP with stenosis of the main pancreatic duct. After six years, computed tomography demonstrated dilatation of the main pancreatic duct in the mid-pancreas. Although we could not confirm the presence of any pancreatic tumor on the basis of imaging modalities alone, cytological examination of the pancreatic juice obtained by endoscopic retrograde pancreatography revealed atypical cells. Therefore, we performed pancreatoduodenectomy and obtained a pathologic diagnosis of PanIN-3 with AIP. The present case is informative in the context of pancreatic carcinogenesis in AIP.

[Asynchronous Bilateral Testicular Infarction with Suspected Polyarteritis Nodosa : A Case Report].

This report documents a case of asynchronous bilateral testicular infarction. The patient was a 42- year-old man who presented with left testicular pain and swelling. He had a past history of right idiopathic testicular infarction and underwent a right orchiectomy 6 years ago. He also had received treatment for 5 years for suspected polyarteritis nodosa (PAN). The left scrotal pain persisted for a week and left orchiectomy was performed. Pathological evaluations demonstrated a benign testis with testicular hemorrhage and chronic vasculopathy. There was no fibrinoid necrosis of medium-size vessel walls which characterizes PAN. In this report, we review the pathogenesis, risk of contralateral testicular infarction, and management of testicular infarction.

Isocitrate dehydrogenase mutation is frequently observed in giant cell tumor of bone.

Giant cell tumors of bone (GCTB) are benign and locally destructive tumors that include osteoclast-type multinuclear giant cells. No available treatment is definitively effective in curing GCTB, especially in surgically unresectable cases. Isocitrate dehydrogenase (IDH) mutations have been reported not only in gliomas and acute myeloid leukemias, but also in cartilaginous tumors and osteosarcomas. However, IDH mutations in GCTB have not been investigated. The IDH mutations are remarkably specific to arginine 132 (R132) in IDH1 and arginine 172 (R172) or arginine 140 (R140) in IDH2; IDH1/2 mutations are known to convert α-ketoglutarate to oncometabolite R(-)-2-hydroxyglutarate. We recently reported that the most frequent IDH mutation in osteosarcomas is IDH2-R172S, which was detected by MsMab-1, a multispecific anti-IDH1/2 mAb. Herein, we newly report the IDH mutations in GCTB, which were stained by MsMab-1 in immunohistochemistry. DNA direct sequencing and subcloning identified IDH mutations of GCTB as IDH2-R172S (16 of 20; 80%). This is the first report to describe IDH mutations in GCTB, and MsMab-1 can be anticipated for use in immunohistochemical determination of IDH1/2 mutation-bearing GCTB.

Familial Intraductal Papillary Mucinous Neoplasm Associated With the Germline MSH6 Missense Variant and Progression of Pancreatic cancer.

OBJECTIVES: Intraductal papillary mucinous neoplasm (IPMN) in individuals with at least one first-degree relative with IPMN is defined as familial IPMN. However, few studies have reported on familial IPMN, its clinical characteristics, or the associated genetic factors. MATERIALS AND METHODS: We report the case of a 58-year-old woman with multifocal IPMN and a mural nodule in the pancreatic body. The patient underwent a distal pancreatectomy and developed pancreatic head cancer 1 year and 6 months postoperatively. The patient had a family history of multifocal IPMN in her father. Therefore, a genetic predisposition to IPMN and pancreatic cancer was suspected. The patient was analyzed for germline variants, and the resected IPMN was subjected to immunohistochemical and somatic variant analyses. RESULTS: Next-generation sequencing revealed a heterozygous germline missense variant in exon 5 of MSH6 (c.3197A>G; Tyr1066Cys). The pathogenicity of this variant of uncertain significance was suspected based on multiple in silico analyses, and the same MSH6 variant was identified in the patient's father's colonic adenoma. The mural nodule in the pancreatic body was pathologically diagnosed as a high-grade IPMN with ossification and somatic KRAS and PIK3CA variants. CONCLUSIONS: This case revealed a possible genetic factor for familial IPMN development and presented interesting clinicopathological findings.