Guidelines on the histopathology of chronic pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and the European Pancreatic Club

BACKGROUND

Chronic pancreatitis is a complex multifactorial fibro-inflammatory disease. Consensus guidelines are needed for the histopathological evaluation of non-autoimmune chronic pancreatitis (CP).

METHODS

An international working group with experts on the histopathology of CP evaluated 15 statements generated from evidence on seven key clinically relevant questions. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the level of evidence available for each statement. To determine the level of agreement, the working group voted on the statements for strength of agreement, using a nine-point Likert scale, and Cronbach's alpha reliability coefficients were calculated.

RESULTS

Strong consensus was obtained for 12 statements relating to all seven key questions including that: the cardinal features of CP are the triad of fibrosis, loss of acinar tissue and duct changes; there are no unique histopathological features that distinguish the different aetiologies of CP; clinical history and laboratory investigations, including genetic testing, are important in establishing the aetiology of CP; there is no reproducible and universally accepted histological grading system for assessing severity of CP, although classification as "mild", "moderate" and "severe" is usually applied; scoring systems for fibrosis are not validated for clinical use; asymptomatic fibrosis is a common finding associated with ageing, and not necessarily evidence of CP; there are no obvious diagnostic macroscopic features of early CP; histopathology is not the gold standard for the diagnosis of CP; and cytology alone is not a reliable method for the diagnosis of CP.

CONCLUSIONS

Cardinal histopathological features of CP are well-defined and internationally accepted and pathological assessment is relevant for the purpose of differential diagnosis with other pancreatic diseases, especially cancer. However, a reliable diagnosis of CP requires integration of clinical, laboratory and imaging features and cannot be made by histology alone.

Classification of subtype using IHC patterns for treatment decision of DCIS

e12035

Background: Ductal carcinoma in situ (DCIS) is a heterogenous group of breast lesion and demands a broad range of surgical management techniques. Previous studies reported the importance of receptor expression and referred to the risk of recurrence.We classified ductal carcinoma in situ (DCIS) into 4 subtypes using IHC staining (ER, PgR, HER2 and Ki-67) and investigated the frequency and their characteristics. Also we investigated whether this classification is related to the risk of recurrence. Methods: 117 women who underwent operation between 2010 and 2012 were included our study. We defined 4 subtypes as follows; luminal A (LA), ER and/or PgR (HR)(+) HER2(-) Ki-67(low), luminal B (LB), HR(+) HER2(-) Ki-67(high) or HR(+) HER2(+),HER2(H), HR(-) HER2(+), and basal-like(BL), HR(-) HER2(-).We also evaluated the risk of recurrence using Van Nuys Prognostic Index (VNPI), an algorithm based on DCIS size, nuclear grade (NG), necrosis, margin width and patient age. Results: The frequency of subtype was as follows; LA 77 cases (65.8%), LB 18 (15.3%), H 14 (12.0%) and BL 8 (6.8%). LA tended to smaller size (average: 3.2cm, range: 0.2-12), low NG (NG1 was 97.4%). In a contrary, H and BL were larger size (average: 3.7cm (H), 4.5cm (BL)) and high NG (these percentages of NG3 were 64.3% (H) and 50.0% (BL)). All of the BL had necrosis. About half of the LA was VNPI 6 and 7, but many of the other subtypes were more than VNPI 7 (p=0.02). Conclusions: Classification of subtypes using IHC patterns is simple, useful and, moreover, that are related to the risk of recurrence. Though it is important whether the woman is BRCA1/2 mutation carrier, we might be determined a treatment of DCIS by the subtype.

Dynamic morphologic change and differentiation from fetal to mature pancreatic acinar cells in rats

BACKGROUND/AIMS

Because of the notion that pancreatic and duodenal homeobox 1 (PdX-1)-positive cells are pancreatic stem cells that contribute to the differentiation and proliferation of exocrine cells, we examined PdX-1-associated changes in the morphology of rat pancreatic acinar cells that occur between the late fetal and early neonatal periods.

METHODS

Light and electron microscopy and PdX-1 and MIB-5 immunohistochemistry were used to examine pancreatic tissues obtained from fetal rats 22 days postconception (dpc), from newborn rats 48 and 72 hours after natural birth, and from rats 7 days after natural birth.

RESULTS

At 22 dpc, the cytoplasm of the acinar cells was large and eosinophilic due to accumulation of dense and numerous zymogen granules. Zymogen granules, rough endoplasmic reticulum, and other organelles were distributed throughout the cytoplasm. At 48 hours, i.e., just after feeding, the cytoplasm appeared smaller, less eosinophilic, and vacuolated. Electron microscopic examination showed cleaved nuclei and fewer zymogen granules. Expression of both PdX-1 and MIB-5 was increased at 48 hours. At 72 hours, acinar cell cytoplasm was decreased in size. At 7 days, the acinar cells were larger, biphasic distribution of zymogen granules was seen on the eosinophilic apical side, and rough endoplasmic reticulum and other ergastoplasms were seen on the basophilic basal side, typical of mature pancreatic acinar cells. Expression of PdX-1 and MIB-5 was markedly decreased in acinar cells.

CONCLUSION

Our findings indicate dynamic PdX-1-associated morphologic change from fetal to mature pancreatic acinar cells between 48 and 72 hours after birth.

Diagnostic challenge: intraductal neoplasms of the pancreatobiliary system

To help pathologists avoid misdiagnosis of intraductal neoplasms arising from the pancreatobiliary system, we report two cases that illustrate diagnostic pitfalls. The first is of a 66-year-old man who complained of appetite loss. An early examination led to a diagnosis of intraductal papillary mucinous neoplasm. Macroscopically, a multilocular cyst without visible mucin was identified. Histologically, the compartments consisted of complex fusion of tubular glands surrounded by dilated pancreatic duct. The neoplasm resembled an acinar cell cystadenocarcinoma. However, the neoplastic cells were negative for trypsin. Thus, the final histopathologic diagnosis was an unusual cystic variant of intraductal tubulopapillary neoplasm (ITPN) of the pancreas. The second case is of a 71-year-old man who complained of right upper quadrant pain. Although bile duct stone was suspected, a polypoid nodule was extracted. Histologically, the nodule was composed of tubular glands, with some complex fusion and focal dysplasia, consistent with carcinoma. In addition, lack of MUC-5AC expression led to an initial impression of ITPN of the bile duct. However, the neoplasm showed dysplastic cells based on the columnar cells resembling pyloric glands, indicating the sequential progression. Thus, the final histopathological diagnosis was intraductal papillary neoplasm of the bile duct with high-grade intraepithelial neoplasia. Because phenotypic variants of intraductal neoplasms of the pancreatobiliary system exist, ITPN and ITPN-mimicking tumor must be carefully differentiated from other intraductal neoplasms.

Immunohistochemical analysis of thymic carcinoma focusing on the possibility of molecular targeted and hormonal therapies

OBJECTIVE

Thymic carcinoma is a rare mediastinal malignant tumor, and in many patients, the tumor is detected in an inoperable advanced stage. Even when chemotherapy is administered to such patients, the patients show a poor response. We investigated new biomarkers of therapeutic molecular targets.

METHODS

This study included 44 patients diagnosed and treated for primary thymic epithelial tumors at Showa University Northern Yokohama Hospital, Showa University Hospital, and Showa University Fujigaoka Hospital from 2003 to 2011. We investigated new biomarkers of therapeutic molecular targets, such as the peroxisome proliferator-activated receptor γ (PPARγ), insulin-like growth factor 1 receptor (IGF1R), epidermal growth factor receptor (EGFR), estrogen receptor (ER), progesterone receptor (PgR), androgen receptor (AR), human epidermal growth factor type 2 (HER2)/neu, CD44, and L-type amino acid transporter 1 (LAT1), in thymic tumors.

RESULT

Immunohistochemical analysis showed that the PPARγ positivity rate in thymic carcinoma was 32 %, which was significantly higher than that in thymoma (4 %). The IGF1R positivity rate in thymic carcinoma was 73 %, which was significantly higher than that in thymoma (27 %).

CONCLUSION

Therefore, by examining the expressions of PPARγ and IGF1R, it would be possible to identify therapy-responsive patients and to improve results of thymic carcinoma treatment.

Gastric- and intestinal-type marker expression in invasive ductal adenocarcinoma of the pancreas

BACKGROUND

Although invasive ductal adenocarcinoma of the pancreas (PDAC) manifests as a relatively uniform histomorphological feature of the pancreatobiliary type, it may be complicated by metaplastic changes and heterogeneous gastric and intestinal elements. This study aimed to investigate the complication rate and clinicopathological significance of such heterogeneous elements.

METHODS

Fifty-nine patients who underwent resection of PDAC were examined in this study. Immunohistochemically, tumors showing high expression (>25%) of the intestinal-type (INT) marker CDX2 were classified as PDAC with INT. Those with high expression (>25%) of the gastric-type (GAS) marker MUC5AC were classified as PDAC with GAS, while those with high expression of both markers were classified as PDAC with INT/GAS. These patients were compared with those with PDAC of the negative group in which neither markers was highly expressed to examine their clinicopathological significance.

RESULTS

In the 59 patients, 31 (52.5%) showed high CDX2 or MUC5AC expression. Twenty-eight patients (47.5%) belonged to a negative group, 11 (18.6%) to a PDAC with INT group, 15 (25.4%) to a PDAC with GAS group, and 5 (8.5%) to a PDAC with INT/GAS group. No significant differences were observed for age, gender, size, localization, T classification, or prognosis among the four groups. Although the PDAC with GAS group had well differentiated types significantly more than the other groups, the rate of lymph node metastasis in this group was significantly higher (PDAC with GAS: 73%; other groups: 36%).

CONCLUSION

Complications with heterogeneous elements are not uncommon in PDAC, and this should be considered during the diagnosis and treatment of PDAC along with histogenesis of the disease.

Autopsy cases of miliary tuberculosis: clinicopathologic features including background factors

To assist physicians, especially young physicians, in identifying tuberculosis (TB) infection before the terminal stage, we analyzed 7 cases of numerous tuberculous granulomas in multiple organs and compared clinical and autopsy findings between cases. Patients ranged in age from 41 to 86 years at the time of death. The main chief complaint was fever of unknown origin (3 of 7 cases [43%]). The main underlying conditions were liver cirrhosis (2 of 7 cases [29%]) and chronic renal failure (2 of 7 cases [29%]). Two patients (29%) had been given methylprednisolone pulse therapy for various lung disorders. Active TB was not diagnosed before autopsy in 4 of 7 (57%) patients. Calcified lesions indicative of old TB were present in 4 of 7 (57%) patients. Thus, miliary tuberculosis may represent a re-emergence of latent TB infection in these cases. Various histologic features of nonreactive exudative inflammation were seen, along with granulomas containing Langhans giant cells with or without caseous necrosis in hypervascular organs, such as the lung, liver, and bone marrow. Physicians should be mindful of the possibility of miliary TB when older patients with hepatorenal disease and a history of TB infection have undergone immunosuppressive treatment. Active tuberculous infection can depend on the presence of an underlying disease and immunocompromise.

Autopsy cases of fulminant bacterial infection in adults: clinical onset depends on the virulence of bacteria and patient immune status

To assist physicians in recognizing the potentially fatal onset of symptoms in cases of fulminant bacterial infection, we analyzed 11 autopsy cases of such infection (four caused by Streptococcus pneumoniae, four by S. pyogenes, one by S. dysgalactiae subsp. equisimilis, one by Staphylococcus aureus, and one by Vibrio vulnificus). Clinicohistopathologic features were evaluated. All patients experienced sudden onset of hypotension and multiple organ failure, leading to unexpected death. Blood culture confirmed bacteremia. The main chief complaints were gastrointestinal symptoms (45%) and limb pain (36%). All had an underlying chronic illness (82%), e.g., a hematologic disorder (36.3%) or liver cirrhosis (27.2%). Necrotizing fasciitis occurred in only 55% of cases, with none involving pneumococcal infection. Laboratory tests typically showed C-reactive protein elevation but without leukocytosis, indicating a high-level inflammatory state. In ten cases, death was attributed to circulatory collapse due to sepsis; severe pulmonary congestion and hemorrhage were present in these cases. The onset of fulminant bacterial infection depends on both virulence of the bacterium and status of the host defense system.

Prognostic relevance of morphological types of intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVE

The clinicopathological significance of four morphological types of intraductal papillary mucinous neoplasms of the pancreas (IPMNs; gastric, intestinal, pancreatobiliary and oncocytic) was assessed.

DESIGN

Retrospective multicentre analysis of 283 surgically resected IPMNs.

RESULTS

Of the 283 IPMNs, 139 were of the gastric type, 101 were intestinal, 19 were pancreatobiliary and 24 were oncocytic. These types were significantly associated with clinicopathological factors including sex (p = 0.0032), age (p = 0.00924), ectatic duct size (p = 0.0245), detection of mural nodules (p = 4.09 × 10⁻⁶), histological grade (p < 2.20 × 10⁻¹⁶), macroscopic types with differential involvement of the pancreatic duct system (p = 3.91 × 10⁻⁵), invasive phenotypes (p = 3.34 × 10⁻¹²), stage (p < 2.20 × 10⁻¹⁶) and recurrence (p = 0.00574). Kaplan-Meier analysis showed significant differences in patient survival by morphological type (p = 5.24 × 10⁻⁶). Survival rates at 5 and 10 years, respectively, were 0.937 (95% CI 0.892 to 0.984) for patients with gastric-type IPMNs; 0.886 (95% CI 0.813 to 0.965) and 0.685 (95% CI 0.553 to 0.849) for those with intestinal-type IPMNs; 0.839 (95% CI 0.684 to 1.000) and 0.734 (95% CI 0.526 to 1.000) for those with oncocytic-type IPMNs; and 0.520 (95% CI 0.298 to 0.909) and undetermined for those with pancreatobiliary-type IPMNs. Analysis by the Cox proportional hazards model comparing prognostic risks determined by stage and the morphological and macroscopic types indicated that staging was the most significant predictor of survival (p = 3.68×10⁻⁸) followed by the morphological type (p = 0.0435). Furthermore, the morphological type remained a significant predictor in a subcohort of invasive cases (p = 0.0089).

CONCLUSION

In this multicentre retrospective analysis, the morphological type of IPMN appears to be an independent predictor of patient prognosis.

Possible recruitment of peripheral blood CXCR3+ CD27+ CD19+ B cells to the liver of chronic hepatitis C patients

It has been suggested that hepatitis C virus (HCV) infects not only hepatocytes but also immune cells, including B cells. HCV infection of B cells is the likely cause of B-cell dysregulation disorders such as mixed cryoglobulinemia, rheumatoid factor production, and B-cell lymphoproliferative disorders that may evolve into non-Hodgkin's lymphoma. To clarify the effects of chronic HCV infection on B-cell dynamics, peripheral B cells from chronic hepatitis C patients (CHC) were characterized. We found that the frequency of CD27(+) B cells, that is memory phenotype, was significantly reduced in the peripheral blood of CHC. At the same time, the amount of IFN-gamma-inducible protein-10 (IP-10), a CXCR3 ligand, was markedly elevated in the plasma of CHC. Furthermore, the CD27(+) B-cell population was found to highly express CXCR3 in CHC, thus suggesting that the CD27(+) B-cell population was recruited from peripheral blood to the inflammatory site of the liver of CHC, where IP-10 is produced. Immunohistochemical analyses of intrahepatic lymphocytes indicated that CXCR3(+) B cells were infiltrated in the liver of CHC. Our results thus offer new insight into the role of memory B cells in the HCV pathogenesis.

Secretion of intelectin-1 from malignant pleural mesothelioma into pleural effusion

Background:

Malignant pleural mesothelioma (MPM) is a rare but fatal tumour. Although most MPM patients show pleural effusion at even the early stage, it is hard to diagnose as MPM at the early stage because a sensitive and reliable diagnostic marker for MPM has not been found in plasma or pleural effusion.

Methods:

In this study, we investigated whether intelectin-1 was specifically contained in MPM cells and the pleural effusion of MPM patient by immunohistochemistry, western blotting, and enzyme-linked immunosorbent assay.

Results:

Malignant pleural mesothelioma cell lines, but not lung adenocarcinoma cell lines, secreted intelectin-1. In immunohistochemistry, epithelioid-type MPMs, but neither pleura-invading lung adenocarcinomas nor reactive mesothelial cells near the lung adenocarcinomas, were stained with anti-intelectin antibodies. Pleural effusion of MPM patients contained a higher concentration of intelectin-1 than that of lung cancer patients.

Conclusion:

These results suggest that detection of intelectin-1 may be useful for a differential diagnosis of epithelioid-type MPM in immunohistochemistry and that a high concentration of intelectin-1 in pleural effusion can be used as a new marker for clinical diagnosis of MPM.

Intraductal oncocytic papillary carcinoma of the pancreas showing numerous hyaline globules in the lumen

Two cases of intraductal oncocytic papillary carcinoma (IOPC) treated surgically were analyzed on light microscopy and immunohistochemistry: that of a 61-year-old man and that of a 55-year-old man. There were no clinical symptoms in either case. Pancreatic abnormalities were discovered incidentally on CT. Various clinical examinations were carried out, and the preoperative diagnosis was intraductal papillary mucinous carcinoma (IPMC) in both cases. Surgery was performed. Macroscopic observation of tissue cross-sections indicated multilocular cystic mass containing polypoid lesions encapsulated by the dilated pancreatic duct. Histologically, the cyst walls were lined by columnar epithelial cells with complex papillary projections associated with oxyphilic cytoplasm, and they were strongly immunoreactive with anti-mitochondrial antibody in the cytoplasm. Electron microscopy showed numerous mitochondria in the cytoplasm. IOPC was diagnosed. Interestingly, amorphous hyaline globules were produced from the oxyphilic cells, which exhibited a bud-like appearance. The hyaline globules were not positive for mucin staining. No case of IPMC with hyaline globules has been reported to date. The production of hyaline globules may be related to oncocytic differentiation. It is suggested that hyaline globules should be regarded as a characteristic of IOPC.

Ductal adenocarcinoma of the pancreas with psammomatous calcification. Report of a case

CONTEXT

Calcification is extremely rare in pancreatic ductal adenocarcinomas, but we may sometimes encounter focal dystrophic calcification.

CASE REPORT

We herein report the case of an 83-year-old female with pancreatic ductal adenocarcinoma associated with diffuse psammomatous calcification. The calcification was preoperatively detected by computed tomography. Numerous psammoma bodies were scattered throughout the tumor. Immunohistochemical positivity of osteopontin, a non-collagenous bone-related protein, was found in the psammoma bodies.

CONCLUSIONS

The possibility of pancreatic ductal adenocarcinoma should therefore be considered for a localized calcified lesion in the pancreas. Therefore, osteopontin may play a significant role in the development of psammoma bodies. Studies to elucidate the prognostic significance of psammoma bodies in pancreatic ductal adenocarcinomas are therefore recommended.

Expression of the tumor suppressor gene maspin and its significance in intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Maspin is a member of the serpin family of protease inhibitors and is thought to inhibit carcinoma invasion, metastasis, and angiogenesis and induce apoptosis. We examined maspin expression immunohistochemically and assessed its significance in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

METHODS

We examined 39 surgically resected specimens of IPMN that included 17 adenomas (IPMAs), 5 borderline tumors (IPMBs), 4 non-invasive carcinomas (non-invasive IPMCs), and 13 invasive carcinomas (invasive IPMCs). Immunostaining was performed according to the EnVision ChemMate method. The degree of maspin expression was scored and assessed according to the percentage and staining intensity of positive cells.

RESULTS

Maspin expression was minimal in normal pancreatic duct epithelium, whereas in IPMNs, maspin was expressed in neoplasms of all stages. Maspin expression increased with increasing grade from IPMAs, IPMBs, to non-invasive IPMCs but decreased significantly in invasive IPMCs. No specific association between maspin expression and mucin type was found. Analysis of maspin expression with respect to clinicopathologic factors in cases of invasive IPMC revealed a greater extent of invasion in cases of low maspin expression and significantly fewer apoptotic cells in the tumor.

CONCLUSIONS

Maspin was expressed at high levels in IPMNs at various stages from adenoma to invasive carcinoma, and our results suggest that maspin may be involved in the occurrence and progression of IPMN. In addition, our data suggest that the apoptosis-inducing action of maspin suppresses invasion and progression of IPMN.

Sudden death caused by fulminant bacterial infection: background and pathogenesis of Japanese adult cases

OBJECTIVE

To analyze a risk factor for the onset of fulminant bacterial infection.

PATIENTS AND METHODS

Nine unexpected acute death cases were clinicopathologically analysed. All cases represented the sudden onset of shock symptom, led to acute death within a few days, and later bacteremia was identified. Pathogens were Streptococcus pneumoniae (S. pneumoniae) (5 cases), group A beta Hemolytic Streptococcus pyogenes (S. pyogenes) (3 cases), and Vibrio vulnificus (V. vulnificus) (1 case).

RESULTS

Seven of the nine patients had underlying chronic illness. S. pneumoniae infection was associated with splenic dysfunction, and group A beta Hemolytic S. pyogenes and V. vulnificus infections were associated with alcoholic liver injury. Group A beta hemolytic S. pyogenes and V. vulnificus infections involved necrotizing fasciitis, and alcoholic liver cirrhosis was confirmed in two of the four patients.

CONCLUSION

Despite the different type of bacteria, the onset of fulminant bacterial infection depended upon depressed bacterial phagocytosis in the liver or spleen. Underlying chronic illnesses should be identified as a predisposing common risk factor. It is important to understand the relations between underlying chronic illness and the onset of fulminant infection.

Immunohistochemical analysis of nestin and c-kit and their significance in pancreatic tumors

The purpose of the present study was to clarify the difference of expression of two stem cell markers, nestin and c-kit, among various pancreatic epithelial tumors and evaluate their utility. Immunohistochemistry was done for 99 surgically resected pancreatic tumor specimens, including 20 ductal adenocarcinoma (DAC), two undifferentiated carcinomas (UC), 31 intraductal papillary-mucinous neoplasms (IPMN), six mucinous cystic neoplasms (MCN), five serous cystadenomas (SCA), six acinar cell carcinomas, two pancreatoblastoma (PB), eight solid-pseudopapillary neoplasms (SPN), and 19 endocrine neoplasms (EN). Nestin was widely expressed in four SPN, one PB, one SCA, sarcoma areas in two UC, one MCN, and one DAC, and an area of oncocytic component in one IPMN. Some of these SPN, SCA and sarcomatous or oncocytic components in which nestin was expressed, also coexpressed c-kit. Additionally, partial (scattered) expression of c-kit was observed in ductal elements of 16 DAC, eight IPMN, five MCN, and one UC, one SCA, and three EN. The eight c-kit-positive IPMN included four of 23 adenoma-to-border lesions and four of eight non-invasive-to-invasive carcinomas. The three EN were all carcinomas. These indicate that expression of two stem cell markers is different by tumor type, but the utility of judging direction or degree of differentiation and malignant grade on the basis of their expression status is suggested.

Clinicopathological findings in fulminant-type pneumococcal infection: Report of three autopsy cases

Reported herein are three autopsy cases of fulminant-type pneumococcal sepsis with disseminated intravascular coagulation (DIC) resulting in death within a few days of onset of symptoms. Two of the three patients had previously had a splenectomy because of a hematological disorder. None of the patients had received pneumococcal vaccination. On post-mortem every organ had congestion as well as bleeding. Interestingly, severe inflammation of the alveoli was absent despite the sepsis. The cause of death was rapidly progressive pneumococcal sepsis leading to DIC and circulatory failure, which appeared to cause pulmonary congestion and hemorrhage without pneumonia. It is important to understand the pathogenesis of fulminant-type pneumococcal infection because it is life-threatening for compromised hosts.

Right pleural effusion in Fitz-Hugh-Curtis syndrome

Right pleural effusion was diagnosed in a 36-year-old woman with right upper quadrant pain and fever. Enhanced pelvic computed tomography performed because of irregular genital bleeding revealed the pelvic inflammatory disease. Upon further questioning, the patient confirmed that she had recently undergone therapy for Chlamydia trachomatis infection. Therefore she was given an injection of tetracycline because we suspected Fitz-Hugh-Curtis syndrome (FHCS), a pelvic inflammatory disease characterized by perihepatitis associated with chlamydial infection. A remarkable clinical response to antibiotics was noted. The right upper quadrant pain was due to perihepatitis, and the final diagnosis was FHCS. Right pleural effusion may be caused by inflammation of the diaphragm associated with perihepatitis. Once chlamydial infection reaches the subphrenic liver, conditions in the closed space between the liver and diaphragm due to inflammatory adhesion may be conductive to chlamydial proliferation. The possibility of FHCS should be considered in patients and carefully distinguished from other abdominal diseases.

Autoimmune pancreatitis: histo- and immunopathological features

In recent years autoimmune pancreatitis (AIP) has been established as a special type of chronic pancreatitis. It is characterized by its histopathological and immunological features. The morphological hallmarks are periductal infiltration by lymphocytes and plasma cells, granulocytic epithelial lesions with focal destruction of the duct epithelium, venulitis, and diffuse sclerosis in advanced stages. AIP has therefore also been called lymphoplasmacytic sclerosing pancreatitis, duct-destructive chronic pancreatitis, or sclerosing pancreatitis. AIP most commonly involves the head of the pancreas and the distal bile duct. Occasionally it is mass-forming, and has been described as an inflammatory myofibroblastic tumor. The presence of more than 20 IgG4-positive plasma cells per high-power field is of high specificity for the tissue diagnosis of AIP.

Autoimmune Pancreatitis: Frequency, IgG4 Expression, and Clonality of T and B Cells

Autoimmune pancreatitis (AIP) is a newly recognized disease. The presence of IgG4 positive plasma cells is thought to be of diagnostic help. In a surgical series of chronic pancreatitis cases, we determined the relative frequency of AIP before and after 1990, analyzed the diagnostic significance of IgG4 expression and examined the presence of oligoclonal T or B-cell populations. The histopathology of 202 surgical specimens of chronic pancreatitis removed between 1975 and 2004 was reviewed and 2 groups were distinguished, 1 of AIP cases and the other of nonautoimmune chronic pancreatitis (non-AIP CP). The intensity of infiltration of pancreatic tissue by IgG4 positive plasma cells and other immune cells was studied immunohistochemically. Finally, T and B-cell clonality was tested by polymerase chain reaction-based analysis. Except for 1 case in 1978, all cases of AIP were observed after 1990. IgG4 positive plasma cells were detected in 72.5% of AIP cases and in 63.1% of non-AIP CP cases. More than 20 cells per high power field were only seen in AIP (sensitivity 43%, specificity 100%). This finding was associated with higher age and grade. Polyclonal T and B-cell populations were found in both AIP and non-AIP CP except for 1 AIP case showing an oligoclonal IgGH-FR3 gene rearrangement. AIP seems to have increased considerably in frequency in the last 2 decades. High density infiltrates of IgG4 positive plasma cells are diagnostic for AIP, but are seen in less than half of the cases. T or B-cell oligoclonality could not be established as a feature of AIP.

[Extrapleural pneumonectomy for malignant pleural mesothelioma]

We analyzed 14 patients with malignant pleural mesothelioma (MPM) who underwent extrapleural pneumonectomy (EPP). 14 men had a mean age of 58.5 years. Preoperarive histological diagnosis was as follows: epithelial 12, biphasic 1, sarcomatous 1. Postoperative diagnosis was: 8, 5, 1, respectively. According to staging of International Mesothelioma Interest Group (IMIG), 3 patients had stage 11 disease, 8 did stage Ill and 3 did stage IV, postoperatively. The operative mortality rate was 7% (1 death), and morbidity rate was 50% (7 cases). The median survival time and 2- and 5-year survival rate were 20.2 months, 33. 8.3%, respectively. EPP for strictly selected patients has been successful in improving survival of patients with negative-node, epithelial type and negative residual tumors.

[Clinical diagnosis of malignant pleural mesothelioma]

Accurate and rapid diagnosis of malignant pleural mesothelioma is important because of its rapid progress. But diagnosis of this disease is often difficult. We reviewed 64 cases with a pathological diagnosis of malignant pleural mesothelioma in the past 14 years in our hospital. We made diagnosis of this disease by cytologic study of pleural fluid (11 cases), percutaneous needle biopsy (16), thoracoscopic biopsy (34), or surgery (2). When cytologic findings are inconclusive, thoracoscopic biopsy is the most effective method for diagnosis and should be done without delay.

Oncocytic non-functioning endocrine tumor of the pancreas

Herein is presented the case of a malignant non-functioning endocrine tumor of the pancreas with oncocytic features, and a discussion on the high incidence of malignancy in oncocytic endocrine pancreatic tumors. The patient was a 65-year-old woman who showed no paraneoplastic symptoms produced by functioning pancreatic endocrine tumors. The primary tumor was located in the body and tail of the pancreas, and had metastasized to the liver. Tumor cells were arranged in a ribbon-like or trabecular pattern and had an abundant eosinophilic cytoplasm containing numerous mitochondria and neurosecretory granules. The cytoplasm of the tumor cells was intensely stained with an antimitochondrial antigen antibody. Most tumor cells stained positively with Grimelius stain and for chromogranin A. Some tumor cells also stained for synaptophysin. However, the tumor cells negatively stained for hormones such as insulin, glucagon, somatostatin, gastrin, vasoactive intestinal peptide and pancreatic polypeptide, for serotonin, and for pancreatic enzymes such as amylase and trypsin. Analysis of 18 oncocytic pancreatic endocrine tumors, consisting of those reported previously and that in the present case, suggests that the high incidence of malignancy in oncocytic endocrine tumors is associated with the high incidence of non-functioning endocrine tumors among them, most of which are malignant.

Evaluation of phosphate removal from water by immobilized phosphate-binding protein PstS

The phosphate (P(i))-binding protein PstS is a member of a family of periplasmic proteins that act as high-affinity receptors for active transport systems in bacteria. PstS protein purified from Pseudomonas aeruginosa was immobilized to N-hydroxysuccinimide-activated Sepharose, packed into a plastic column (5 x 70 mm), and examined for its potential ability to remove P(i) from water. The PstS-Sepharose column completely removed P(i) from 32P-labeled pond water containing about 0.5 microM P(i) (0.015 mg P per liter). More than 90% of 32P-P(i) that was retained in the column could be eluted by washing with low-pH water.

Clinical significance of nuclear morphometry at the invasive front of T1 colorectal cancer and relation to expression of VEGF-A and VEGF-C

OBJECTIVES

To better understand the metastatic potential of T1 colorectal cancer, we investigated variations in nuclear morphometry and expression of angiogenic factors in cancer cells at the invasive front. Sixty-five patients who had undergone curative resection were entered.

METHODS

Nuclear shape factor, area, width, and proportion of cells with large nucleoli in all cells were determined in two high-power magnification areas at the invasive front of the tumor. We then performed the Ward method for cluster analysis. A dendrogram revealed that cases fell into two clusters: cluster A with high atypical nuclei and cluster B with low atypical nuclei. Expression of vascular endothelial growth factor-A (VEGF-A) and -C were evaluated immunohistochemically at the invasive front of the tumor.

RESULTS

Nuclear atypia, and VEGF-C expression were associated significantly with lymph node metastasis by univariate analysis. Nuclear atypia was independently and significantly associated with lymph node metastasis by multivariate analysis. Whereas VEGF-A expression was associated with nuclear atypia, VEGF-C expression was not showed. Nuclear atypia, strong VEGF-A or -C expressions were not associated with the depth of invasion.

CONCLUSION

Nuclear morphometry and expression of angiogenic factors at the invasive front are useful prognostic markers of lymph node metastasis, even cases with slight invasion.

Sequential progression and intraductal spread of invasive ductal adenocarcinoma of the pancreas arising from around the main pancreatic duct

A 76-year-old woman was admitted to our hospital after increased transaminase, hepato-biliary enzyme levels, and tumor markers were found. Abdominal contrast computed tomography revealed a mass (20 x 18 mm) in the uncus of the pancreas. Magnetic resonance cholangiopancreatography showed an abrupt narrowing with the dilatation of the peripheral main pancreatic duct (MPD) in the pancreatic head. Endoscopic retrograde cholangiopancreatography showed only dilatation of the lower bile duct; insertion of the cannula was not seen because the MPD was obstructed. The patient underwent a Whipple-pancreatoduodenectomy. Histopathological and immunohistochemical examinations led to a diagnosis of sequential progression and intraductal spread of invasive ductal adenocarcinoma of the pancreas arising from around the main pancreaticduct. Interestingly, the intraductal spread was approximately 20 mm to the point where the carcinoma began to infiltrate. To the best of our knowledge, there have been no other reported cases of such broad intraductal spread, indicating that noninvasive lesions that replace the normal epithelia can be broader than those reported previously.

Intraductal tubular neoplasms of the pancreas: histogenesis and differentiation

OBJECTIVES

Intraductal neoplasms of the pancreas are generally referred to as intraductal papillary mucin-producing neoplasms (IPMNs), according to the WHO classification system. Herein, we report that morphologic and immunohistochemical features of intraductal tubular carcinoma (ITC) are quite different from those of intraductal papillary mucinous carcinoma (IPMC).

METHODS

We analyzed histogenesis and differentiation of ITC by light microscopy and immunohistochemistry.

RESULTS

Histologically, ITC was characterized as an intraductal nodular appearances with a monotonous tubular growth pattern without papillary projection. ITC showed de novo-like appearance without sequential progression usually observed in IPMC, suggesting that ITC is a homogeneous neoplasm. Cuboidal tumor cells in ITC resembled normal pancreatic duct epithelia, and the characteristic growth pattern of ITC replaced that of normal pancreatic duct epithelium. Immunohistochemically, ITC cells were positive for MUC-1 on the apical side of the cell membrane. In contrast to ITC cells, IPMC cells were negative for MUC-1, and ductal adenocarcinoma cells were strongly positive for MUC-1, as was the stroma around the cancer. The immunohistochemical staining pattern of DUPAN-2 resembled that of MUC-1. Interestingly, localization of MUC-1 and DUPAN-2 staining in ITC cells was similar to that in normal pancreatic ductules. ITC cells were negative for MUC-2 and MUC-5AC. In contrast, most IPMC cells were positive for MUC-2 and MUC-5AC.

CONCLUSION

Based on our histologic and immunohistochemical findings, the intraductal pancreatic neoplasm (IPN) can be classified into 2 groups: IPN with gastrointestinal differentiation and IPN with pancreatic duct differentiation. Our present data indicated that ITC cells may arise directly from duct epithelia without progression and possessed pancreatic duct differentiation. On the basis of our data, we suggest that classification of pancreatic neoplasms in the WHO and The Armed Forces Institute of Pathology (AFIP) systems should be reconsidered.

Cyopathologic and histologic features of biphasic pulmonary blastoma: a case report

BACKGROUND

Biphasic pulmonary blastoma is a rare malignant neoplasm of debatable histogenesis. Although well described histologically, it is scarcely mentioned in the cytologic literature.

CASE

A 78-year-old man reporting intermittent hemoptysis was admitted to the hospital. Chest radiography revealed a right-sided pulmonary mass. Cytologic examination of tumor specimens revealed 2 types of malignant cells. The smears were highly cellular, with a necrotic background. The stromal cells had predominantly round to ovoid or spindle-shaped nuclei and scant cytoplasm, and the nucleoli had slightly irregular borders with coarsely aggregated chromatin. The epithelial cells were arranged in sheets and glandular configurations. The cytoplasm of these cells was finely vacuolated or foamy, with indistinct cellular boundaries; eccentrically located nuclei were hyperchromatic and had irregularly shaped nucleoli. The cell block preparation showed a distinctly biphasic malignant tumor with the classic morphologic features of pulmonary blastoma.

CONCLUSION

A preoperative diagnosis ofpulmonary blastoma is difficult to obtain by cytopathologic methods. A diagnosis of biphasic pulmonary blastoma should be considered whenever epithelial cells and a separate population of stromal cells are seen in a pulmonary exfoliative cytology specimen.

Pathological assessment of pancreatic endocrine tumors for metastatic potential and clinical prognosis

The prognostic significance of several pathological factors (tumor size, mitotic index, Ki-67 labeling index, and vascular invasion) and expression of exocrine markers (CA19-9, CEA, AFP, and trypsin) in pancreatic endocrine tumors was studied. A total of 20 specimens of metastasizing (n = 10) and non-metastasizing (n = 10) tumors were subjected to histological and immunohistochemical examination. The metastasizing tumors showed significantly larger size, higher Ki-67 labeling index, increased number of mitotic cells, and more frequent vascular invasion in comparison with the non-metastasizing tumors. It was difficult to determine the effect of individual factors on clinical outcome because of slow disease progression in almost all cases. Numerous mitotic cells and widespread necrosis, however, were thought to indicate a poor prognosis, and tumors with these characteristics were regarded as high-grade malignant endocrine carcinomas. In one case, one-third of the tumor tissue comprised trypsin-positive cells, the outcome was comparatively poor, and the behavior of the tumor resembled that of mixed acinar-endocrine carcinoma. A simple multifactorial approach may be effective for the identification of tumors at increased risk of metastasis, but it remains difficult to determine clinical prognosis. It is essential to at least distinguish high-grade endocrine carcinomas from the more common endocrine tumors.

Osteopontin expression in proliferated bile ductules: the correlation with liver damage in fulminant hepatitis

There have been many reports about the severity of hepatic necrosis caused by fulminant hepatitis; however, the relation between proliferated bile ductules and osteopontin (OPN) expression in inflamed areas in each of the clinical forms of fulminant hepatitis has not been described. To analyze the mechanism in the onset of fulminant hepatitis, we classified not only 16 autopsy cases of fulminant hepatitis into two clinical forms--acute and subacute--but also 3 autopsy cases of late-onset hepatic failure (LOHF) associated with fulminant hepatitis, and examined liver specimens by light microscopy and immunohistochemistry and also serum transaminase levels. Histopathologic study revealed that some of the proliferated bile ductules were associated directly with deteriorating hepatocytes and that bile plugs were present in the proliferated bile ductules. The value of the proliferative cell nuclear antigen labeling index (PCNA-L I) for proliferated bile ductules was very high during the acute form of fulminant hepatitis. Immunohistochemical analysis revealed that OPN expression was higher in the proliferated bile ductules of acute-form fulminant hepatitis than in cirrhotic and normal liver bile ducts. Transaminase levels in acute-form fulminant hepatitis were significantly elevated in comparison with levels in the other forms of the disease. Comparison of acute form fulminant hepatitis with the subacute form and LOHF showed OPN expression in proliferated bile ductules and serum aspartate aminotransferase (ALT)max to be decreased in the subacute form of fulminant hepatitis. OPN expression is an important marker of the degree of liver inflammation, and its regulation mechanism is very important to understanding the pathophysiology of fulminant hepatitis.

Relation of E-cadherin and beta-catenin expression to pit pattern in colorectal cancer

To investigate the usefulness of pit pattern to estimate depth of submucosal invasion and the mechanism of change in pit pattern by tumor character in colorectal cancer, we investigated the relation between pit pattern and immuno-histochemical E-cadherin and beta-catenin expression. Fifty-seven colorectal tumors including 37 submucosal invasive carcinomas, 10 high-grade adenomas and 10 cases of advanced carcinomas invading into the muscularis propria were divided into a non-VN and VN group according to a modification of the Kudo classification system. In addition, distance between the invasive front and muscularis mucosae was measured, and histological and immunohistochemical expression of E-cadherin and beta-catenin in the superficial portion and invasive portion were examined. Many tumors with deep invasion were classified in the VN group. Among the submucosal invasive carcinomas in the VN group, there was a significantly higher number with deep invasion than with slight invasion. All submucosal invasive cancers with lymphatic invasion also had deep submucosal invasion. Immunohistochemical analysis revealed significant loss of normal membrano-cytoplasmic beta-catenin expression in the superficial area of cancers in the VN group. Submucosal carcinoma with deep invasion also had significant loss of membrano-cytoplasmic expression of beta-catenin in the superficial area. Pit pattern is useful not only to predict tumor character but also to estimate depth of invasion. Change in pit pattern may be associated with abnormality of beta-catenin expression.

Mucinous cystadenoma of the pancreas 17 years after excision of gallbladder because of a choledochal cyst

A 56-year-old woman who had undergone excision of the gallbladder because of a choledochal cyst had a tumorous lesion of the pancreas identified by upper abdominal ultrasonography, but an operation was not carried out, because there was no apparent increase in the cystic mass and no elevation of serum tumor markers. In October 2001, she was admitted to our hospital to check for malignancy because of elevated levels of the tumor marker Dupan-2. Abdominal enhanced computed tomography and upper abdominal ultrasonography revealed a large multilocular cystic mass in the body to tail of the pancreas. Endoscopic retrograde cholangiopancreatography showed elongation of the common duct that communicates with the common bile duct and the main pancreatic duct, indicating an anomalous arrangement of the biliary and pancreatic duct system. No apparent communications between the cystic mass and the main pancreatic duct were observed. In January 2002, the patient underwent a spleen-preserving distal pancreatectomy, and histopathological and immunohistochemical examinations led to the diagnosis of pancreatic mucinous cystadenoma with ovarian-like stroma. The mucinous cystadenoma was detected 17 years after the operation for the choledochal cyst. To the best of our knowledge, no documented case reports of mucinous cystadenoma of the pancreas associated with a choledocal cyst have been reported to date. We present here the first case report of pancreatic mucinous cystadenoma occurring in the body to tail of the pancreas, associated with a choledocal cyst.

Prognostic significance of the maspin tumor suppressor gene in pulmonary adenocarcinoma

PURPOSE

Maspin is a member of the serpin family and has tumor suppressor activity. We evaluated maspin expression in pulmonary adenocarcinoma in relation to a number of clinicopathological features.

METHODS

Maspin expression was examined immunohistochemically in a series of 78 pulmonary adenocarcinomas by the EnVision ChemMate method.

RESULTS

. Thirty-seven of 78 cases (47%) showed distinct maspin expression (maspin-positive group) and 41 (53%) did not (maspin-negative group). Maspin expression was not associated significantly with most clinicopathological variables including sex, age, tumor size, primary tumor, lymph node metastasis, visceral pleural invasion, pulmonary metastasis, and disease stage. However, the maspin-positive group had a better 5-year survival rate (62%) than did the maspin-negative group (42%). The difference in the 5-year survival rate was greatest in stage II patients (maspin-positive group, 69%; maspin-negative group, 17%; P = 0.048).

CONCLUSION

Our data indicate that maspin has prognostic significance for pulmonary adenocarcinoma. A better understanding of the role of maspin in tumor suppression may be helpful for development of novel chemotherapies for patients with this deadly tumor.

Immunohistochemical evaluation of tissue-specific proteolytic enzymes in adenomas containing foci of early carcinoma: correlations with cathepsin D expression and other malignant features

BACKGROUND

Cathepsin D (CD) is an aspartyl lysosomal protease, and the prognostic value of CD expression has been studied in a variety of tumors, however, its role in early adenocarcinomas remains unclear.

AIM OF THE STUDY

We evaluated the expression of CD in a series of colorectal adenomas with severe dysplasia containing foci of early carcinoma and compared the results to several histopathological and immunohistochemical features.

METHODS

Adenomas were obtained by endoscopic polypectomy from 33 patients. Twenty-four of the 33 adenomas contained well-differentiated adenocarcinomas and nine adenomas contained moderately differentiated adenocarcinomas.

RESULTS

Positive CD expressions were observed in 25% of well-differentiated adenocarcinomas and in 66.7% of moderately differentiated adenocarcinomas (p < 0.05). Of the 12 adenocarcinomas with positive CD expression, four had positive CD expression in their adenomas (p < 0.01), 6 showed positive Ki-67 expression in their adenomas (NS), and 10 had positive p53 expression in their adenomas (p < 0.05). No significant association was seen between the level of CD expression and adenoma size.

CONCLUSIONS

The expression of CD in adenocarcinoma correlated significantly with differentiation, and with the levels of CD and p53 expression in the adenomas of the polyp.

Clinicopathological significance and molecular regulation of maspin expression in ductal adenocarcinoma of the pancreas

We evaluated the biological relevance of maspin expression in pancreatic ductal adenocarcinoma and studied regulatory mechanisms of maspin gene activation in pancreatic carcinoma cell lines. Maspin expression was immunohistochemically detected in a series of 57 pancreatic ductal adenocarcinomas, 51 (90%) of which were classified as high-expressers. In lymph node metastases, maspin expression was somewhat decreasingly found in 39/49 (80%). Maspin high-expressers showed predominantly a low histological grade (p=0.013). Moreover, maspin expression was found in two mixed ductal-endocrine carcinomas, but not in 10 endocrine tumors and the surrounding normal pancreatic tissues. Using a luciferase reporter system, maspin promoter activity was induced in the maspin-positive pancreatic cancer cell lines as well as maspin-negative PANC-1 cells. Additionally, treatment with the DNA methyltransferase inhibitor, 5-aza-2' deoxycytidine, and histone deacetylase inhibitor, trichostatin A, led to re-expression of maspin mRNA in PANC-1 cells. Our results indicate that maspin expression is up-regulated in most if not all pancreatic ductal adenocarcinomas and may be related to the development and differentiation, and that DNA methylation and histone deacetylation may suppress maspin gene activation in pancreatic cancer cells.