Adenocarcinoma arising in a gastrocystoplasty.

Gastrocystoplasty is a form of surgical bladder augmentation or neobladder used to restore bladder capacity and compliance in children and in patients with neurogenic bladder. Other forms of bladder augmentation include ileocystoplasty and colocystoplasty. Reported complications of gastrocystoplasty include post-operative bleeding, haematuria, stricture, metabolic alkalosis and rupture of the gastric segment. There are reports of adenocarcinomas arising in the setting of ileocystoplasty and colocystoplasty. However, the first case of adenocarcinoma arising in the setting of a gastrocystoplasty is reported.

Jaundice caused by a clinically undetectable T-cell lymphoma infiltrating the sphincter of Oddi.

Malignant lymphoma rarely presents with jaundice. We describe a patient who had a unique etiology for painless jaundice, dilated ducts, and a normal ampulla of Vater. A Whipple's procedure was performed for the suspicion of pancreatic cancer, and initial pathological review detected only mild focal chronic pancreatitis. Seven months later, the patient developed ascites, retroperitoneal mass, and splenomegaly caused by a T-cell lymphoma. Reevaluation of the Whipple's specimen revealed previously unrecognized microscopic infiltration and fibrosis of the sphincter of Oddi by atypical T-lymphocytes. Obstructive jaundice caused by a clinically undetectable primary duodenal T-cell lymphoma has not been previously reported and is contrasted with other causes of jaundice associated with malignant lymphoma and ampullary lesions.

Haloalkane hydrolysis with an immobilized haloalkane dehalogenase.

Haloalkane dehalogenase from Rhodococcus rhodochrous was covalently immobilized onto a polyethyleneimine impregnated gamma-alumina support. The dehalogenating enzyme was found to retain greater than 40% of its original activity after immobilization, displaying an optimal loading (max. activity/supported protein) of 70 to 75 mg/g with an apparent maximum (max. protein/support) of 156 mg/g. The substrate, 1,2,3-trichloropropane, was found to favorably partition (adsorb) onto the inorganic alumina carrier (10 to 20 mg/g), thereby increasing the local reactant concentration with respect to the catalyst's environment, whereas the product, 2,3-dichloropropan-1-ol, demonstrated no affinity. Additionally, the inorganic alumina support exhibited no adverse effects because of solvent/component incompatibilities or deterioration due to pH variance (pH 7.0 to 10.5). As a result of the large surface area to volume ratio of the support matrix and the accessibility of the bound protein, the immobilized biocatalyst was not subject to internal mass transfer limitations. External diffusional restrictions could be eliminated with simple agitation (mixing speed: 50 rpm; flux: 4.22 cm/min). The pH-dependence of the immobilized dehalogenase was essentially the same as that for the native enzyme. Finally, both the thermostability and resistance toward inactivation by organic solvent were improved by more than an order of magnitude after immobilization.

Sepsis-induced apoptosis causes progressive profound depletion of B and CD4+ T lymphocytes in humans.

Patients with sepsis have impaired host defenses that contribute to the lethality of the disorder. Recent work implicates lymphocyte apoptosis as a potential factor in the immunosuppression of sepsis. If lymphocyte apoptosis is an important mechanism, specific subsets of lymphocytes may be more vulnerable. A prospective study of lymphocyte cell typing and apoptosis was conducted in spleens from 27 patients with sepsis and 25 patients with trauma. Spleens from 16 critically ill nonseptic (3 prospective and 13 retrospective) patients were also evaluated. Immunohistochemical staining showed a caspase-9-mediated profound progressive loss of B and CD4 T helper cells in sepsis. Interestingly, sepsis did not decrease CD8 T or NK cells. Although there was no overall effect on lymphocytes from critically ill nonseptic patients (considered as a group), certain individual patients did exhibit significant loss of B and CD4 T cells. The loss of B and CD4 T cells in sepsis is especially significant because it occurs during life-threatening infection, a state in which massive lymphocyte clonal expansion should exist. Mitochondria-dependent lymphocyte apoptosis may contribute to the immunosuppression in sepsis by decreasing the number of immune effector cells. Similar loss of lymphocytes may be occurring in critically ill patients with other disorders.

IFNgamma and lymphocytes prevent primary tumour development and shape tumour immunogenicity.

Lymphocytes were originally thought to form the basis of a 'cancer immunosurveillance' process that protects immunocompetent hosts against primary tumour development, but this idea was largely abandoned when no differences in primary tumour development were found between athymic nude mice and syngeneic wild-type mice. However, subsequent observations that nude mice do not completely lack functional T cells and that two components of the immune system-IFNgamma and perforin-help to prevent tumour formation in mice have led to renewed interest in a tumour-suppressor role for the immune response. Here we show that lymphocytes and IFNgamma collaborate to protect against development of carcinogen-induced sarcomas and spontaneous epithelial carcinomas and also to select for tumour cells with reduced immunogenicity. The immune response thus functions as an effective extrinsic tumour-suppressor system. However, this process also leads to the immunoselection of tumour cells that are more capable of surviving in an immunocompetent host, which explains the apparent paradox of tumour formation in immunologically intact individuals.

Solid low-grade in situ carcinoma of the breast: role of associated lesions and E-cadherin in differential diagnosis.

Low-grade solid in situ carcinomas of the breast are difficult to classify. The authors investigated 12 cases of in situ carcinomas with equivocal features and correlated their histologic attributes with those of the associated invasive carcinomas as well as with E-cadherin expression in both in situ and invasive disease. E-cadherin-positive in situ lesions were invariably associated with invasive carcinomas of the ductal type. In situ carcinomas that were E-cadherin negative were associated with invasive carcinomas of the lobular type in five of six cases. In all cases, the invasive carcinomas showed the same pattern of E-cadherin reactivity as the in situ lesions. Sharply defined cellular membranes, necrosis, and occasional microacini were seen in both E-cadherin-positive and negative in situ carcinomas, whereas intracytoplasmic lumina and a noncohesive appearance were seen only in E-cadherin-negative lesions.

IFN-gamma action in the media of the great elastic arteries, a novel immunoprivileged site.

Infection of medial smooth muscle cells with gamma-herpesvirus 68 (gammaHV68) causes severe chronic vasculitis that is restricted to the great elastic arteries. We show here that persistence of disease in the great elastic arteries is (a) due to inefficient clearance of viral infection from this site compared with other organs or other vascular sites, and (b) associated with failure of T cells and macrophages to enter the virus-infected elastic media. These findings demonstrate immunoprivilege of the media of the great elastic arteries. We found that IFN-gamma acted on somatic cells during acute infection to prevent the establishment of medial infection and on hematopoietic cells to determine the severity of disease in this site. The immunoprivileged elastic media may provide a site for persistence of pathogens or self antigens leading to chronic vascular disease, a process regulated by IFN-gamma actions on both somatic and hematopoietic cells. These concepts have significant implications for understanding immune responses contributing to or controlling chronic inflammatory diseases of the great vessels.

Undifferentiated embryonal sarcoma with unusual features arising within mesenchymal hamartoma of the liver: report of a case and review of the literature.

Undifferentiated embryonal sarcoma (UES) is a rare and highly malignant hepatic neoplasm, affecting almost exclusively the pediatric population. It has replaced malignant mesenchymoma, under which diagnostic term the first three cases were described. A link between embryonal sarcoma and mesenchymal hamartoma of the liver (MHL) has long been proposed, because of clinicopathologic overlaps of these entities; however, until recently, this association remained tenuous. Cases of UES arising in a background of mesenchymal hamartoma of the liver have previously been reported in two teenage girls. Discovery of a similar genetic abnormality in MHL and UES has clinched the supposed link between them. There have also been two reports of UES with prominent cystification, one associated with peripheral eosinophilia, and thereby masquerading as hydatid cyst of the liver. We report a case of UES arising in a young boy with MHL, with unusual histologic features, including large mesothelial-lined cysts and ectopic adrenal cortical tissue under Glisson's capsule.

Malignant peripheral nerve sheath tumors with t(X;18). A pathologic and molecular genetic study.

Spindle cell sarcomas often present the surgical pathologist with a considerable diagnostic challenge. Malignant peripheral nerve sheath tumor, leiomyosarcoma, fibrosarcoma, and monophasic synovial sarcoma may all appear similar histologically. The application of ancillary diagnostic modalities, such as immunohistochemistry and electron microscopy, may be helpful in the differentiation of these tumors, but in cases in which these adjunctive techniques fail to demonstrate any more definitive evidence of differentiation, tumor categorization may remain difficult. Cytogenetic and molecular genetic characterization of tumors have provided the basis for the application of molecular assays as the newest components of the diagnostic armamentarium. Because the chromosomal translocation t(X;18) has been observed repeatedly in many synovial sarcomas, it has been heralded as a diagnostic hallmark of synovial sarcoma. To formally test the specificity of this translocation for the diagnosis of synovial sarcoma, RNA extracted from formalin-fixed, paraffin-embedded tissue from a variety of soft tissue and spindle cell tumors was evaluated for the presence of t(X;18) by reverse transcriptase-polymerase chain reaction. Although 85% of the synovial sarcomas studied demonstrated t(X;18), 75% of the malignant peripheral nerve sheath tumors in our cohort also demonstrated this translocation. We conclude that the translocation t(X;18) is not specific to synovial sarcoma and discuss the implications of the demonstration of t(X;18) in a majority of malignant peripheral nerve sheath tumors.

Analysis of mucosal gene expression in inflammatory bowel disease by parallel oligonucleotide arrays.

DNA arrays capable of simultaneously measuring expression of thousands of genes in clinical specimens from affected and normal individuals have the potential to provide information about disease pathogenesis not previously possible. Few studies have applied mRNA profiling to diseases involving complex tissues like the intestinal mucosa, reflecting the unique challenges inherent to this type of analysis. We report the analysis of mucosal gene expression in ulcerative colitis (UC) patients and inflamed and noninflamed control specimens. Genes can be used as markers for cell recruitment, activation, and mucosal synthesis of immunoregulatory molecules. Self-organizing maps were applied to cluster and analyze gene expression patterns and were paired with histopathological scores to identify genes associated with increased disease activity. Clustering was achieved on the basis of differences in expression levels across individual specimens. Several inflammatory mediators were identified as likely determinants of characteristic histological features of active UC. These results provide proof of principle for application of functional genomics to larger inflammatory bowel disease populations for gene discovery, to facilitate identification of disease subgroups on the basis of gene expression signatures, and for prediction of disease behavior or optimal therapeutic intervention.

Merlin, DAL-1, and progesterone receptor expression in clinicopathologic subsets of meningioma: a correlative immunohistochemical study of 175 cases.

The molecular pathogenesis of meningiomas is poorly characterized. Loss of NF2 (merlin) expression has been reported in 30%-80% of all sporadic meningiomas. Recently, we found that loss of expression for a second Protein 4.1-family tumor suppressor. DAL-1, is also common. A biologically important role for progesterone receptor (PR) has also been proposed based on its reported inverse relationship with tumor grade. In order to better define the pathogenetic roles of these proteins, we studied the merlin, DAL-1, and PR immunoprofiles in 175 fully characterized meningiomas, including nonrecurring versus recurring benign, proliferative versus brain invasive atypical and anaplastic subtypes. Loss of expression for either Protein 4.1-family tumor suppressor (merlin or DAL-1) was almost universal (92%), with combined losses being common (58%). Individually, absence of merlin or DAL-1 protein was detected in 74% and 76% respectively, with no significant differences among the 5 subsets. PR immunoreactivity was commonly associated with retained DAL-1 expression (p < 0.001) and with tumor grade, with 51% of benign, 21% of atypical, and 11% of anaplastic tumors staining positive (p < 0.001). We conclude that PR immunohistochemistry may have diagnostic utility in meningothelial neoplasms. Protein 4.1-family tumor suppressor losses are likely important early events in meningioma pathogenesis, whereas PR expression is associated with benignity.

Injection of iron compounds followed by induction of the stress response causes tissue injury and apoptosis.

To determine whether iron-laden tissue subsequently stimulated to produce the stress ("heat shock") response-sustained injury, hindlimbs of male ND4 mice were injected with iron salts, hemin, or hemoglobin. The stress response was induced with sodium arsenite or with heat. Ulcers appeared at the injection site. Tissues were analyzed by three distinct techniques-electron microscopy, TUNEL stain, and agarose gel electrophoresis of low molecular weight DNA-which collectively suggest that the tissue injury is, at least in part, the consequence of accelerated apoptosis. The data suggest that the toxicity of free iron is amplified by induction of the stress (heat shock) response to signal a programmed response. This model and mechanism may have implications in pathological processes ranging from the cutaneous wounds of venous stasis disease to the tissue failure of multiple organ dysfunction.

Renal cell carcinoma with rhabdoid features.

Neoplasms with rhabdoid features have been reported at many anatomic sites. In the kidney, rhabdoid tumors are typically found in children, whereas only rare examples have been reported in adults. Little is known of renal cell carcinomas (RCCs) that exhibit rhabdoid features. The objective of this study was to determine the incidence of RCC with rhabdoid attributes and characterize the histologic, immunophenotypic, and ultrastructural features by retrospective analysis of 480 consecutively identified cases of RCC in radical nephrectomy specimens. Immunohistochemical evaluation was performed in cases with rhabdoid foci using a panel of antibodies to pancytokeratin (pan-CK), CK7, CK20, epithelial membrane antigen (EMA), S-100 protein, desmin, vimentin, neuron-specific enolase (NSE), muscle-specific actin (MSA), smooth muscle actin (SMA), human melanoma, black-45 (HMB-45), and glial fibrillary acidic protein (GFAP). Electron microscopy was also performed in selected cases. The presence and extent of rhabdoid foci in relation to pathologic stage and grade were assessed. Twenty-three of 480 cases of RCC (4.7%) exhibited rhabdoid features. The 23 patients were all adults with a mean age of 61.8 years (age range, 33-84 yrs). Fifteen of the patients were men and eight were women. Histologically, the rhabdoid foci were typified by sheets and clusters of variably cohesive, large epithelioid cells with vesicular and often eccentric nuclei, prominent nucleoli, and large, paranuclear intracytoplasmic hyaline globules (inclusions). The presence of these rhabdoid features was related to high histologic Fuhrman grade of the nonrhabdoid carcinoma component, with an incidence of 0 of 84 grade I cases, eight of 300 grade 2 cases (2.6%), six of 70 grade 3 cases (8.9%), and nine of 26 grade 4 cases (34.6%; p = 3 x 10(-9)). The rhabdoid foci were all high grade. The presence of rhabdoid foci was also found in higher stage carcinomas. A total of 52% (12 of 23) of RCC cases with rhabdoid features exhibited extrarenal extension compared with 28% (24 of 92) of contemporary RCCs without rhabdoid features (p = 0.03). The size of the rhabdoid component ranged from 1 mm to more than 2 cm and comprised 1% to 50% of the renal mass. Immunoreactivity for vimentin (100%), NSE (79%), and panCK (56%) was present in the majority of cases. Substantial percentages of cases were immunopositive for EMA (47%) and S-100 protein (37%), with minimal to no immunohistochemical reactivity for CK7 (5%), SMA (5%), CK20 (0%), desmin (0%), MSA (0%), HMB-45 (0%), and GFAP (O%). A distinctive globular, paranuclear reaction pattern was found for the cytokeratin, EMA, and vimentin immunostains. Ultrastructurally, the rhabdoid cells had paranuclear intermediate filament aggregates or paranuclear condensation of organelles, often associated with peripheral vacuolization. Adult RCCs may harbor a rhabdoid component, and these neoplasms can be regarded as "composite" tumors. Rhabdoid elements are important to identify because of their high-grade nature, and association with high stage. Adult RCC with rhabdoid elements should be distinguished from pure rhabdoid tumors of kidney, in light of their clinicopathologic differences. Rhabdoid differentiation in adult renal cell carcinoma may represent clonal divergence and/ or evolution, and emergence of a particularly aggressive element.

WT1 staining reliably differentiates desmoplastic small round cell tumor from Ewing sarcoma/primitive neuroectodermal tumor. An immunohistochemical and molecular diagnostic study.

Differentiating desmoplastic small round cell tumor (DSRCT) from another similar small round cell tumor of childhood, the Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET), can be difficult because morphologic and immunohistochemical features overlap. We studied the predictive value of immunohistochemistry with an antibody to the C-terminal region of the Wilms tumor (WT1) protein for differentiating DSRCT from EWS/PNET in 24 malignant small round cell tumors that had been previously diagnosed as DSRCT or EWS/PNET by standard methods. We performed reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in cases with available tissue as a confirmatory measure: 6 of 13 DSRCTs were informative by RT-PCR, and 6 of 6 showed an EWS-WT1 fusion; all 13 DSRCTs showed strong, definitive nuclear staining with the WT1 antibody. All 11 EWS/PNETs were WT1 antibody negative; 7 of 11 cases classified as EWS/PNET were informative by RT-PCR, and 7 of 7 showed an EWS-FLI-1 fusion. For cases in which the morphologic and immunohistochemical features are consistent with a diagnosis of DSRCT, WT1 antibody staining predicts the EWS-WT1 translocation with high sensitivity and specificity and is, therefore, useful for differentiating DSRCT from EWS/PNET when genetic information is unavailable.

Rapid onset of intestinal epithelial and lymphocyte apoptotic cell death in patients with trauma and shock.

OBJECTIVE: Apoptosis is a cellular suicide program that can be activated by cell injury or stress. Although a number of laboratory studies have shown that ischemia/reperfusion injury can induce apoptosis, few clinical studies have been performed. The purpose of this study was to determine whether apoptosis is a major mechanism of cell death in intestinal epithelial cells and lymphocytes in patients who sustained trauma, shock, and ischemia/ reperfusion injury. DESIGN: Intestinal tissues were obtained intraoperatively from 10 patients with acute traumatic injuries as a result of motor vehicle collisions or gun shot wounds. A control population consisted of six patients who underwent elective bowel resections. Apoptosis was evaluated by conventional light microscopy, laser scanning confocal microscopy using the nuclear staining dye Hoechst 33342, immunohistochemical staining for active caspase-3, and immunohistochemical staining for cytokeratin 18. SETTING: Academic medical center. PATIENTS: Patients with trauma or elective bowel resections. MEASUREMENTS AND MAIN RESULTS: Extensive focal crypt epithelial and lymphocyte apoptosis were demonstrated by multiple methods of examination in the majority of trauma patients. Trauma patients having the highest injury severity score tended to have the most severe apoptosis. Repeat intestinal samples obtained from two of the trauma patients who had a high degree of apoptosis on initial evaluation were negative for apoptosis at the time of the second operation. Tissue lymphocyte apoptosis was associated with a markedly decreased circulating lymphocyte count in 9 of 10 trauma patients. CONCLUSIONS: Focal apoptosis of intestinal epithelial and lymphoid tissues occurs extremely rapidly after injury. Apoptotic loss of intestinal epithelial cells may compromise bowel wall integrity and be a mechanism for bacterial or endotoxin translocation into the systemic circulation. Apoptosis of lymphocytes may impair immunologic defenses and predispose to infection.

Fixation and epitope retrieval in diagnostic immunohistochemistry: a concise review with practical considerations.

Diagnostic immunohistochemistry (DIHC) is an extremely valuable technological development that has revolutionized the practice of surgical pathology over the past 25 years. Like any laboratory procedure, however, the precise concatenation of methodological details that are used by any given investigator has a major effect on final results. In this overview, the authors consider several of these variables and illustrate how they may be optimized in an effective and efficient approach to quality assurance in the DIHC laboratory. The great majority of this discussion concerns processing factors as they affect paraffin section-based immunohistology because that is still, by far, the most common adjunctive morphologic procedure (AMP) used in hospital pathology. However, information is also presented on elements of tissue processing that affect other analyses as well. The material presented here is a direct reflection of the conjoint experiences of the authors. Although we discuss our preferences regarding many technical aspects of this discipline, we certainly do not mean to imply that ours are the only methods that should be utilized. Nevertheless, it is hoped that they may serve to crystallize basic concepts surrounding fixation, processing, and optimal performance of AMPs.

CD31 immunoreactivity in small round cell tumors.

CD31 has been shown to be a sensitive and specific marker for endothelial differentiation among epithelioid and spindled-pleomorphic human neoplasms. However, the role of this marker in the evaluation of small round cell tumors has not been evaluated. Formalin-fixed, paraffin-embedded tissue sections from 276 small round cell tumors, including 85 Ewing's sarcoma/primitive neuroectodermal tumors (ES/PNET), 52 rhabdomyosarcomas, 10 extraabdominal polyphenotypic small cell tumors, six desmoplastic small cell tumors, 11 neuroblastomas, 23 Wilms' tumors, 20 retinoblastomas, 13 esthesioneuroblastomas, and 56 small cell malignant lymphomas were stained with CD31 (JC/70A, 1:40), using a modified avidinbiotin-peroxidase complex technique, after citrate buffer microwave epitope retrieval. Among nonlymphoid small round cell tumors, four of 85 ES/PNET were at least focally reactive. No other lesion in this group was positive. In contrast, the majority of well-differentiated (11 of 17), intermediately differentiated (two of three), and lymphoblastic lymphomas (three of three) were positive. Small cleaved lymphomas (three of 13 follicular, one of 13 diffuse) were less often reactive, whereas small noncleaved lesions were negative. Although reactivity for CD31 in ES/PNET is uncommon, the presence of platelet/endothelial cell adhesion molecule in a small cell neoplasm should not in isolation be taken as evidence of hematopoietic origin. These results further define the utility of CD31 in the evaluation of human neoplasms.

CD99 and cytokeratin-20 in small-cell and basaloid tumors of the skin.

Although it is classically a deep soft-tissue tumor of childhood, primitive neuroectodermal tumor (PNET) can occur at any age and may occasionally involve cutaneous sites. Merkel cell carcinoma (MCC) and basaloid neoplasms of cutaneous adnexa are the principal diagnostic alternatives to that tumor. The common expression of CD99 in PNET and cytokeratin-20 (CK20) in MCC suggests that these markers may be of value in this diagnostic setting, but they have not been rigorously examined in other small-cell and basaloid lesions of the skin. Accordingly, we evaluated CD99 and CK20 reactivity in formalin-fixed, paraffin-embedded sections of 30 MCC, five cutaneous metastases of pulmonary small-cell neuroendocrine carcinomas, 10 primary cutaneous adnexal carcinomas with basaloid features, 18 benign basaloid adnexal neoplasms of the skin (nine spiradenomas and nine cylindromas), and two cutaneous PNETs, using a standard immunohistologic technique and microwave-mediated epitope retrieval. Of the 30 MCC, 12 showed crisp membrane staining for CD99. Among the remaining tumors, only the two PNETs were positive for that marker. Although the majority of MCCs did not label for CD99, the pattern of reactivity in positive cases was indistinguishable from that observed in PNETs. Eighteen of 27 MCCs that were stained for CK20 were reactive for that protein, in contrast to metastatic small cell carcinomas, cutaneous PNETs, and appendageal skin tumors, which were uniformly negative for this marker. However, a subset of nine tumors, which were most consistent with MCC on clinical grounds, was CD99 positive and CK20 negative. Hence, reliance on CD99 alone as a diagnostic marker for PNET in this context cannot be recommended. Rather, careful assessment of the clinical presentation, together with extended immunophenotyping that includes other lineage markers and, when possible, cytogenetic analysis for characteristic chromosomal aberrations, remains the best means of separating MCC from PNET. Finally, the lack of CD99 reactivity in basaloid adnexal neoplasms of the skin suggests a utility in their differential diagnosis from cutaneous tumors with neuroendocrine or neuroectodermal differentiation.