Immunostaining With Immunoglobulin G Subclass Antibody Cocktail for Diagnosis of Type 1 Autoimmune Pancreatitis.

BACKGROUND.: Immunoglobulin (Ig) G4-related diseases (RDs) are systemic diseases in which serum IgG4 levels are frequently elevated. They can cause diffuse or focal tumor formation, organ swelling, and tissue thickening in organs infiltrated by IgG4+ plasma cells. The diagnostic criteria for IgG4-RDs include an IgG4/IgG ratio >40%, but counting IgG+ cells can be difficult because of the weakness of IgG staining density. We hypothesized that an antibody cocktail of mixed IgG1, IgG2, IgG3, and IgG4 (AC-IgG) might give immunohistochemistry results comparable with those of IgG in IgG4-RD. METHODS.: We compared AC-IgG reactivity with IgG expression in type 1 autoimmune pancreatitis (AIP), a representative IgG4-RD. We compared immunohistochemistry results using AC-IgG and IgG-only in 10 cases of AIP. The coefficient of variation (Cv) was used to analyze differences between AC-IgG and IgG findings in AIP by 13 board-certified pathologists. RESULTS.: Although mean values for IgG+ cells did not significantly differ between AC-IgG (34.3; range = 27.4-37.1) and IgG (30.0; range = 23.0-45.6; P = .6254), Cv was lower for AC-IgG (33.4%) than for IgG (51.4%; regression equation; y[IgG] = 0.988x + 0.982; correlation coefficient = 0.907). The data showed that the results of both methods were largely consistent. CONCLUSION.: AC-IgG could replace IgG to count IgG+ cells because of its lower Cv.

Malignant peritoneal mesothelioma diagnosed 50 years post-radiotherapy for ovarian cancer in a patient with a history of multiple malignancies: An autopsy case.

As the number of long-term cancer survivors is increasing, the incidence of post-irradiation malignant mesothelioma may also increase. We herein present the case of an 85-year-old female patient with a history of several surgeries for solid tumors and radiotherapy to the pelvis, who presented with abdominal pain and diarrhea. The patient's general condition gradually worsened and she succumbed to cardiopulmonary arrest triggered by vomiting ~3 months after the onset of the abdominal symptoms. An autopsy revealed malignant intestinal obstruction caused by peritoneal mesothelioma. Irradiation is a known risk factor for malignant mesothelioma, which may develop ~10-30 years after radiotherapy. To the best of our knowledge, this is the first report of a patient with malignant mesothelioma developing ~50 years after radiotherapy. The aim of the present study was to remind physicians that malignant mesothelioma should be considered in the differential diagnosis of patients with a history of radiotherapy who present with gastrointestinal symptoms.

Lower number of 5-hydroxymethylcytosine-expressing cells in plasma cell myeloma than in reactive plasma cell hyperplasia: a useful immunohistochemical approach for identification of neoplastic plasma cells.

Plasma cell myeloma (PCM) is a haematological malignancy defined by aberrant proliferation of plasma cells in the bone marrow. For the diagnosis of PCM, immunostaining of light chains or surface marker analyses by flow cytometry is needed but sometimes difficult. Aberrant methylation at the carbon-5 position of cytosine results in 5-methylcytosine (5-mC), which is a well-known epigenetic hallmark of cancer in mammals. 5-mC is oxidised to 5-hydroxymethylcytosine (5-hmC), and low 5-hmC levels occur in several cancers and haematopoietic malignancies. We compared the expression of 5-hmC by immunohistochemistry (IHC) in neoplastic plasma cells in 31 PCM cases and in non-neoplastic plasma cells in 14 benign reactive lesions. The mean percentage of 5-hmC-positive cells was 7.8% and 81.5% in PCM and plasma cell hyperplasia, respectively. Thus, the frequency of 5-hmC-positive cells in PCM specimens was significantly lower than that in reactive plasma cell hyperplasia (p < 0.001 by Student's t-test). IHC of 5-hmC is a useful method for differentiating neoplastic plasma cells from non-neoplastic plasma cells in reactive lesions even in tiny tissue samples unsuitable for flow cytometric analyses or for immunoglobulin light chain IHC.

Promoter hypomethylation of SKI in autoimmune pancreatitis.

The relationship between methylation abnormality and autoimmune pancreatitis (AIP)-a representative IgG4-related disease-has not yet been elucidated. We identified SKI might have a significant methylation abnormality in AIP through methylation array analysis using the Illumina Infinium Human Methylation 450K BeadChip array, and investigated the relationship of SKI with AIP clinicopathological features. The methylation rate of SKI was assessed by quantitative SYBR green methylation-specific PCR, and the degree of SKI expression in tissue specimens was assessed by immunohistochemistry in 10 AIP cases, 14 cases of obstructive pancreatitis area in pancreatic ductal adenocarcinoma (PDA) without a history of AIP, and 9 normal pancreas (NP) cases. The SKI methylation ratio was significantly lower in AIP than in PDA and NP. Additionally, the immunohistochemical staining-index (SI) score for SKI was significantly higher in AIP than NP, although there was no significant difference between AIP and PDA. There was a strong negative correlation between SI score and SKI methylation ratio, and between the serum concentrations of IgG4 and the SKI methylation ratio. There was a moderate positive correlation between the serum concentrations of IgG4 and SI. SKI is thought to be an oncogene indicating that SKI hypomethylation and carcinogenesis might be linked to AIP. Furthermore, the correlation between serum concentrations of IgG4 and SKI methylation levels suggest SKI might be involved in the pathogenesis of AIP. However, the role of SKI has not been clearly elucidated. Further studies are needed to understand further the function of SKI.

[Comparison of ventral and dorsal lymph node metastases of obturator nerve in radical prostatectomy].

OBJECTIVE: In this study, we assessed the significance of complete dissection of the dorsal lymph node of the obturator nerve during radical prostatectomy. PATIENTS AND METHODS: Fifty-six patients undergoing open radical prostatectomy and pelvic lymph node dissection for treatment of prostate cancer were included in this study. Neoadjuvant hormonal therapy and radiation therapy were not performed in any of the patients. First, pelvic lymph node dissection was performed between the external iliac vein and obturator nerve and classified as "ventral lymph node of the obturator nerve". Then, the tissue located in the area between the obturator nerve and the surface of the obturator internus muscle was removed and classified as "dorsal lymph node of the obturator nerve". Both lymph nodes were meticulously examined by identical pathologist. Lymph node yields, lymph node positive rate, and the factors associated with lymph node metastasis were studied. RESULTS: Eight of the 56 patients had pelvic lymph node metastases (6 were high risk and 2 were intermediate risk according to the D'Amico's criteria). In the 8 node-positive patients, only 1 patient had positive lymph node in "ventral lymph node of the obturator nerve" exclusively. Four patients had positive lymph node exclusively in "dorsal lymph node of the obturator nerve" and 3 patients had in both "ventral and dorsal lymph nodes of the obturator nerve". The total lymph node yields from "ventral lymph node of the obturator nerve" and "dorsal lymph node of the obturator nerve" were 459 (8.2 per patient) and 117 (2.1 per patient), respectively. The total numbers of positive lymph nodes from "ventral lymph node of the obturator nerve" and "dorsal lymph node of the obturator nerve" were 6 and 12, respectively. Lymph node positive rate was significantly higher in "dorsal lymph node of the obturator nerve" (10%) than "ventral lymph node of the obturator nerve" (1.3%) (P < 0.0001). The level of prostate-specific antigen (> or = 20 ng ml), Gleason score sum at prostate biopsy (> or = 9), and lymph node yield (> or = 16) were associated with lymph node status on univariate analysis. In multivariate analysis, only lymph node yield was associated with lymph node status. CONCLUSIONS: Dorsal lymph nodes of the obturator nerve should be dissected completely during radical prostatectomy.

A reversal in the vascularity of metastatic liver tumors from colorectal cancer after the cessation of chemotherapy plus bevacizumab: contrast-enhanced ultrasonography and histological examination.

OBJECTIVE: To assess the effect of chemotherapy plus bevacizumab on tumor vessels, as well as the reversibility of this effect, using contrast-enhanced ultrasonography (CEUS) and histology in patients with metastatic liver tumors derived from colorectal cancer. METHODS: The study included 12 patients who received chemotherapy plus bevacizumab, experienced a reduction in tumor vascularity as demonstrated by CEUS and consequently underwent liver resection. CEUS was performed before and after four courses of chemotherapy and before surgery. The numbers of microvessels highlighted by anti-CD34 antibodies in the viable tumor tissue were counted to quantify the microvessel density (MVD). As a control, 12 surgical specimens from 12 patients who had not received chemotherapy were examined. RESULTS: A reversal of tumor vascularity was observed in 10 of 12 patients. In two patients, the vascularity remained reduced. The MVD in the treatment group was significantly lower than that observed in the group without treatment. CONCLUSION: The data suggest that the tumor vessels regenerated substantially, although the effect of chemotherapy plus bevacizumab remained weak for approximately 6 weeks after the cessation of treatment. Therefore, future research must determine whether bevacizumab should be used prior to surgery.

A case of primary biliary cirrhosis that complicated with combined hepatocellular and cholangiocellular carcinoma.

Primary biliary cirrhosis (PBC) is frequently complicated with hepatocellular carcinoma (HCC), but complication with combined hepatocellular and cholangiocellular carcinoma (cHCC-CC) or cholangiocellular carcinoma (CCC) has not been reported. Here, we describe a case of PBC in which cHCC-CC occurred. The patient was a 70-year-old man who had developed jaundice at 62 years old. He was diagnosed with PBC based on a liver biopsy and blood tests. In August 2006, blood tests showed elevated alpha-fetoprotein, and a liver tumor in the right lobe and a metastatic lymphadenopathy in the back near to the head of the pancreas were detected by abdominal contrast-enhanced CT. A (18)F-fluorodeoxyglucose-PET scan showed accumulation of the tracer in the tumor and in a lymph node at the back of the pancreas. The tumor and lymph node were removed, and the tumor was diagnosed pathologically as cHCC-CC based on the presence of features of HCC and CCC. This case is the first to show that a patient with PBC can develop cHCC-CC. This is of interest, since cHCC-CC may originate in hepatic stem cells or hepatic precursor cells. This case also suggests that cHCC-CC should be included as a differential diagnosis for a liver tumor complicated with PBC.

A case of granulocyte-colony stimulating factor-producing hepatocellular carcinoma confirmed by immunohistochemistry.

Granulocyte-colony stimulating factor (G-CSF) is a naturally occurring glycoprotein that stimulates the proliferation and maturation of precursor cells in the bone marrow into fully differentiated neutrophils. Several reports of G-CSF-producing malignant tumors have been published, but scarcely any in the hepatobiliary system, such as in hepatocellular carcinoma (HCC). Here, we encountered a 69-yr-old man with a hepatic tumor who had received right hepatic resection. He showed leukocytosis of 25,450/microL along with elevated serum G-CSF. Histological examination of surgical samples demonstrated immunohistochemical staining for G-CSF, but not for G-CSF receptor. The patient survived without recurrence for four years, but ultimately passed away with multiple bone metastases. In light of the above, clinicians may consider G-CSF-producing HCC when encountering patients with leukocytosis and a hepatic tumor. More cases are needed to clarify the clinical picture of G-CSF-producing HCC.

Granulomatous transformation of capillary lesions in pulmonary-renal syndrome autologously induced anti-glomerular basement membrane disease in Wistar-Kyoto rats.

BACKGROUND: Pulmonary-renal syndrome is characterized by pulmonary hemorrhage and rapidly progressive glomerulonephritis in various immunological states. Histopathological analysis of pulmonary-renal syndrome is not yet complete. METHODS: Wistar-Kyoto (WKY) rats were sensitized using the noncollagenous (NC1) domain of type IV collagen from bovine kidney as an antigen. Histopathology of the kidneys and lungs was investigated with light microscopy, immunohistochemistry and electromicroscopy. Expression levels of cytokine mRNA were determined by real-time RT-PCR using renal tissue of rats. RESULTS: Macrophage-rich granulomatous glomerulonephritis and alveolar capillaritis accompanied with pulmonary hemorrhage were induced by the sensitization. The humoral antibody against NC1 was detected on the glomerular and alveolar capillary walls. Th2 cytokine IL-10 was dominant over Th1 cytokine IFN-gamma in renal tissues of WKY rats. CONCLUSION: The granulomatous transformation seemed to be induced by macrophage conspicuous capillaritis under dominant cellular immune reactions in WKY rats. In addition to Th1 cytokines, Th2 cytokines may also participate in the formation of granulomatous lesions.

Primitive neuroectodermal tumor as a differential diagnosis of CD56-positive tumors in adults.

A 33-year-old Japanese man was referred to our hospital after a huge intrapelvic tumor with bilateral hydronephrosis was found following persistent lumbago. Natural killer/T-cell lymphoma was suspected due to positive immunostaining for CD56, but CHOP therapy was ineffective. Re-evaluation of the tumor cells showed that they were positive for CD99, neuron-specific enolase, and synaptophysin and had a t(11 ; 22) (q24 ; q12) translocation, leading to the revised diagnosis of primitive neuroectodermal tumor (PNET). Systemic chemotherapies and radiation therapy were added to surgical resection, and no recurrence has been detected for 3 years. Taken together, PNET may be considered in adult patients with CD56-positive tumors.

Granulocyte-colony stimulating factor-producing pancreatic adenosquamous carcinoma showing aggressive clinical course.

Herein, we encountered an 89-year-old woman with pancreatic cancer who presented with fever without infective focus, leukocytosis of 45,860 /microL, and elevation of serum granulocyte-colony stimulating factor (G-CSF). The patient could not receive any curative therapy due to an extremely aggressive clinical course. Specimens taken at necropsy revealed an adenosquamous carcinoma positive for G-CSF by immunohistochemistry; it was only the second reported case to date. She was finally diagnosed with G-CSF-producing pancreatic cancer. In light of the above, clinicians should consider the presence of G-CSF-producing tumors, including pancreatic cancer, when presented with patients showing leukocytosis of unknown origin and fever without infective focus.

Zygomycosis presenting as acute myocardial infarction during hematological malignancies.

Here we report two patients with hematological malignancies associated with complications of fatal cardiac zygomycosis. The first case, a 72-year-old man with myelodysplastic syndrome being treated with low-dose cytarabine, died of sudden cardiac arrest. An autopsy revealed disseminated zygomycosis accompanied with occlusion of the coronary artery by fungal thrombi. The second case, a 52-year-old woman with acute lymphoblastic leukemia, developed febrile neutropenia and skin eruptions with induration on the face and extremities during the first induction chemotherapy. She experienced sudden bradycardia with unstable hemodynamics and died of acute myocardial infarction. Histological examination of a skin biopsy demonstrated zygomycosis. In light of the above, it should be kept in mind that cardiac zygomycosis might occur in hematologically compromised patients presenting with acute myocardial infarction.

A case of primary Epstein-Barr virus-associated cutaneous diffuse large B-cell lymphoma unassociated with iatrogenic or endogenous immune dysregulation.

Cutaneous Epstein-Barr virus (EBV)-associated B-cell lymphoma (EBVBL) in non-immunocompromised patients is very rare. Here, we report a case of cutaneous EBVBL in a 72-year-old Japanese woman without any signs of immunosuppression. She showed repeated high fever and skin eruptions on the face, limbs and palms. Histological diagnosis was diffuse large B-cell lymphoma. EBV infection was detected by in situ hybridization and Southern blotting. Immunostaining for viral proteins showed the patient to be positive for latent membrane protein 1 (LMP-1) and negative for Epstein-Barr virus nuclear antigen-1 (EBNA-2), indicating that a type II latency EBV infection pattern.

[A case of nonocclusive mesenteric ischemia (NOMI) which occurred in a patient with torsion of gallbladder].

We report a case of nonocclusive mesenteric ischemia (NOMI) which occurred in a patient with torsion of gallbladder. A 91-year-old woman was admitted to the hospital and was diagnosed of acute cholecystitis. The next day, she went into shock. Then, we diagnosed her illness as torsion of gallbladder by computed tomography and ultrasonography, and performed an emergency operation. After cholecystectomy, it was recognized that the wide range of the small intestine had become necrotic sporadically. We diagnosed it as NOMI, and performed the wide resection of the small intestine followed by making double stomas. There is no previous report of NOMI associated with torsion of gallbladder. We guess the cause of NOMI in this case would be dehydration because of gallbladder torsion. NOMI has high mortality. Early diagnosis and early treatment are of great importance in NOMI.

Post-inflammatory glomerular remodeling is influenced by transformed mesangial cells.

To identify the role of transformed mesangial cells (MC) during glomerular remodeling, anti-thymocyte-1 (Thy1) nephritis; modified Thy1 nephritis (injections of anti-Thy1 antibody four times, weekly); and Thy1 nephritis treated with signal transduction inhibitor 571 (Thy1 + STI); were analyzed. At week 1 the index of MC proliferation in modified Thy1 nephritis and in mesangiolysis in Thy1 + STI nephritis was highest among the three models. From week 4, the index of alpha-smooth muscle actin (alpha-SMA) was significantly higher in modified Thy1 nephritis than the other two models. Production of the mesangial matrix including type IV collagen was increased in modified Thy1 but inhibited in Thy1 + STI nephritis. In contrast to modified Thy1 nephritis, the capillary numbers in glomeruli recovered to normal at week 4 in Thy1, and at week 8 in Thy1 + STI nephritis. At week 12, both the adhesive and sclerotic index was significantly higher in modified Thy1 than in the other two models. Data suggest that a moderate amount of mesangial matrix results in a complete repair of capillary loops. Overproduction of the mesangial matrix retards capillary remodeling and finally induces glomerulosclerosis. Insufficient mesangial matrix delays the repair of capillary loops. In conclusion, transformed MC may influence glomerular remodeling by changing the amount of mesangial matrix.

Glomerulosclerosis develops in Thy-1 nephritis under persistent accumulation of macrophages.

To clarify the relationship between macrophages and development of glomerulosclerosis, the authors developed a new experimental nephritis model with macrophages persisting in Thy-1 nephritis. Methyl-cellulose was administered intraperitoneally in addition to the intravenous injection of the anti-Thy-1 antibody to Wistar rats. Foamy macrophages influxed into the lytic mesangium and stayed to form nodular aggregates. Mesangial cells proliferated with the formation of extracellular matrices around these nodular aggregates of macrophages. Immunohistochemical analyses revealed that alpha-smooth muscle actin (alpha-SMA) was expressed in the proliferative area around these nodules of foamy macrophages from day 7. Type I collagen and type IV collagen were also expressed around the foamy macrophages in correspondence with alpha-SMA expression from day 7. The electron microscopic study revealed that collagen fibrils were formed around the transformed mesangial cells. The expression of platelet endothelial cell adhesion molecule-1 (PECAM-1, CD31), a marker of glomerular vasculature endothelial cells, was not found in the area occupied by the foamy macrophages, suggesting the impairment of glomerular reconstruction. Macrophages may participate in the progression of glomerulosclerosis in Thy-1 nephritis by enhancing the production of the extracellular matrix through transformed mesangial cells and preventing reconstruction of the capillary network.

A case of an ABO-incompatible renal transplant with abundant intratubular basement membrane immune deposits.

We present a case of a 30-year-old man who received an ABO-incompatible renal transplant from his mother in 1996 after haemodialysis for 3 years. Although his renal function was stable, a renal biopsy was performed while he was in hospital for treatment of herpes zoster in 1999. Light microscopy provided no evidence of obvious acute or chronic rejection but a double contour pattern was observed in many tubular basement membranes (TBM). Immunofluorescence microscopy revealed deposits of IgG and C3 on the TBM in the absence of glomerular deposition. Massive electron-dense deposits were observed clearly by electron microscopy within TBM, revealing splitting and lamellation. This implies that the deposits resulted from the formation of immune complexes, but not from anti-TBM antibody. Although the role of TBM deposits in tubular injury is controversial, careful observation of patients with such deposits may be required because of their potential ability to induce immune reactions.

Hydronephrosis associated with retroperitoneal fibrosis and sclerosing pancreatitis.

Sclerosing pancreatitis is associated with raised concentrations of IgG4. We treated 22 patients with sclerosing pancreatitis, and identified and followed-up three with concomitant hydronephrosis caused by ureteral mass, later diagnosed as retroperitoneal fibrosis. We histologically examined the ureteral and pancreatic lesions of these patients and noted abundant infiltration of IgG4-bearing plasma cells in both tissues. Treatment with corticosteroids lowered serum concentrations of IgG4. IgG4 might also have a pathological role in a systemic fibrosing process that includes pancreatic and retroperitoneal lesions.