Renal angiomyolipoma, fat-poor variant--a clinicopathologic mimicker of malignancy.

Angiomyolipomas, composed of thick-walled blood vessels, smooth muscle, and adipose tissue, belong to the perivascular epithelioid cell neoplasms (PEComas), a family of tumors believed to be derived from perivascular epithelioid cells which co-express smooth muscle and melanocytic markers. Although most angiomyolipomas are benign, a subset of PEComas has metastatic potential. The pathologic and clinical spectrum of these tumors continues to evolve.

Liver allograft antibody-mediated rejection with demonstration of sinusoidal C4d staining and circulating donor-specific antibodies.

The importance of antibody-mediated rejection (AMR) in ABO-compatible liver transplantation is controversial. Here we report a prospective series of liver recipients with a preoperative positive crossmatch. To establish the diagnosis of AMR in liver recipients, the criteria described for kidney allografts were adopted.

Tryptase staining of mast cells may differentiate eosinophilic esophagitis from gastroesophageal reflux disease.

Objectives: Mast cells may contribute to the pathogenesis of eosinophilic esophagitis (EoE), but their role in diagnosis is unknown. Our aim was to determine whether tryptase staining of esophageal mast cells differentiates EoE from gastroesophageal reflux disease (GERD) and has utility for diagnosis of EoE.

Methods: We performed a case-control study comparing patients with EoE, defined by consensus guidelines, to GERD patients with eosinophils on esophageal biopsy.

Management of branch-duct intraductal papillary mucinous neoplasms of the pancreas: observation with MR imaging.

Purpose: To evaluate the clinical outcomes of conservative management by observation with MRI of patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs).

Materials And Methods: Twenty-three consecutive patients, who were followed up by MRI with magnetic resonance cholangiopancreatography (MRCP) over a period of more than 9 months after initial MRI examinations, were enrolled in this study. On MRI, number of lesions, the maximum diameter of BD-IPMNs, lesion location, the presence of associated dilatation of main pancreatic duct (MPD), the presence of enhancing mural nodules within the lesion and the presence of interval change were retrospectively reviewed on initial and follow-up MR images in consensus by two radiologists.

Cutting edge: IFN-gamma is a negative regulator of IL-23 in murine macrophages and experimental colitis.

IL-23 regulation is a central event in the pathogenesis of the inflammatory bowel diseases. We demonstrate that IFN-gamma has anti-inflammatory properties in the initiation phase of IL-23-mediated experimental colitis. IFN-gamma attenuates LPS-mediated IL-23 expression in murine macrophages.

Esophageal dilation in eosinophilic esophagitis: safety and predictors of clinical response and complications.

Background: Esophageal strictures resulting from eosinophilic esophagitis present management challenges, and high rates of rents and perforation have been reported.

Objective: To assess the safety of esophageal dilation in eosinophilic esophagitis and to characterize predictors of both clinical response and complications of the procedure.

Design: Retrospective study of the University of North Carolina eosinophilic esophagitis database.

Evaluation of a non-invasive method to detect cytomegalovirus (CMV)-DNA in stool samples of patients with inflammatory bowel disease (IBD): a pilot study.

Background: A severe flare of colitis in patients with IBD treated with immunosuppressive therapy may be complicated by an underlying CMV infection. The aim of this pilot study was to investigate the diagnostic efficacy of quantitative polymerase chain reaction (PCR) to detect CMV DNA in stool samples of IBD patients.

Methods: Twenty-one patients with a severe flare of IBD, incompletely responding or refractory to either steroids or immunosuppressive agents, were included in the study.

Inter- and intraobserver reliability and validation of a new method for determination of eosinophil counts in patients with esophageal eosinophilia.

Background: Diagnosis of eosinophilic esophagitis (EoE) requires quantification of esophageal eosinophilia.

Aims: The aims of this study were to assess inter- and intraobserver reliability for measuring esophageal eosinophil counts and to validate a novel method of determining tissue eosinophil density using digitized histopathology slides.

Methods: Patients were selected from the University of North Carolina EoE clinicopathologic database.

Clinical, endoscopic, and histologic findings distinguish eosinophilic esophagitis from gastroesophageal reflux disease.

Background & Aims: Features of eosinophilic esophagitis (EoE) and gastroesophageal reflux disease (GERD) overlap; because they cannot be differentiated on the basis of eosinophil counts alone, it can be a challenge to distinguish these disorders. We aimed to characterize the clinical, endoscopic, and histologic features of EoE and GERD and to identify factors that might be used to differentiate them.

Methods: We performed a retrospective case-control study on data collected from 2000 to 2007.

Modulation of the intestinal microbiota alters colitis-associated colorectal cancer susceptibility.

It is well established that the intestinal microbiota plays a key role in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) collectively referred to as inflammatory bowel disease (IBD). Epidemiological studies have provided strong evidence that IBD patients bear increased risk for the development of colorectal cancer (CRC). However, the impact of the microbiota on the development of colitis-associated cancer (CAC) remains largely unknown.

KRAS/BRAF mutation status and ERK1/2 activation as biomarkers for MEK1/2 inhibitor therapy in colorectal cancer.

Phase II clinical trials of mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitors are ongoing and ERK1/2 activation is frequently used as a biomarker. In light of the mutational activation of BRAF and KRAS in colorectal cancer, inhibitors of the Raf-MEK-ERK mitogen-activated protein kinase are anticipated to be promising. Previous studies in pancreatic cancer have found little correlation between BRAF/KRAS mutation status and ERK1/2 activation, suggesting that identifying biomarkers of MEK inhibitor response may be more challenging than previously thought.

Oral budesonide for the therapy of post-liver transplant de novo inflammatory bowel disease: a case series and systematic review of the literature.

Background: The therapy for posttransplant IBD is clinically challenging. Patients receiving liver transplants are immunosuppressed to prevent rejection, but via an unknown mechanism develop de novo IBD in spite of receiving some of the same medications used for therapy in traditional IBD. In the published literature most of the patients who developed de novo IBD were treated with traditional corticosteroids.

Flat colorectal cancers are genetically determined and progress to invasion without going through a polypoid stage.

Growing evidence suggests that flat colorectal cancers (CRC) account for 10% to 20% of all CRCs and that these are frequently associated with more advanced pathologies. However, controversy exists as to the origin and progression of flat CRCs compared with the more common polypoid-type morphology. We report using the azoxymethane mouse model for human CRC that KK/HIJ and I/LNJ mice develop different frequencies of flat and polypoid tumors; 83% of colon tumors in I/LNJ mice are flat compared with only 19% in KK/HIJ mice, indicating a strong genetic predisposition to the development of specific CRC morphologies.

Pancreatic cancer: correlation of MR findings, clinical features, and tumor grade.

Purpose: To assess the frequency of occurrence of poorly-marginated and focally-defined pancreatic ductal adenocarcinoma by MRI and to determine whether these appearances correlate with clinical features and histopathological grade.

Materials And Methods: Institutional review board with waiver of informed consent was obtained for this HIPAA compliant study. A total of 33 patients (16 female, 17 male, mean age = 63.

Prediction of nonsentinel lymph node metastasis in sentinel node-positive breast carcinoma.

The incidence of nonsentinel (NSN) lymph node metastases in patients with a tumor-positive sentinel (SN) lymph node varies greatly from 20% to 70% in the published literature. Current practice is that most patients with a positive SN (micro- and macrometastases) undergo a complete axillary dissection. However, it has been shown by other investigators that a large number of patients with a positive SN do not necessarily need a complete axillary dissection.

Free-floating thrombus of the carotid artery: literature review and case reports.

Background: Free-floating thrombus (FFT) of the carotid artery is an uncommon entity that usually presents as an acute emergency. Management is based on case reports and series because the natural history and optimal treatment are unknown. This study was conducted to systematically review the world literature in an attempt to better understand FFT, its presentation, distribution, management, and outcome.

Determination of ultrafilterable prolactin: elimination of macroprolactin interference with a monomeric prolactin-selective sample pretreatment.

Context: Macroprolactin (macroPRL), present in as many as 25% of serum specimens with elevated serum prolactin concentrations, can cause apparent hyperprolactinemia in the absence of clinical features and lead to unnecessary clinical, laboratory, and neuroradiological workups.

Objective: To develop an ultrafiltration method that eliminates macroPRL interference from PRL immunoassays.

Design: The method involves centrifugation of undiluted serum in a Centricon-100 filter device followed by a PRL assay of the serum ultrafiltrate.

Multifocal gastrointestinal stromal tumor (GIST) of the stomach in an 11-year-old girl.

A previously healthy 11-year-old girl presented with an 8-month history of anemia and left upper quadrant abdominal pain. US examination demonstrated a 9-cm cystic mass with a fluid-fluid level in the left upper quadrant with unclear organ of origin. Abdominal MR imaging demonstrated a complex cystic mass, likely arising from the stomach.

Fat poor renal angiomyolipoma: patient, computerized tomography and histological findings.

Purpose: We reviewed our experience with fat poor cases of angiomyolipoma.

Materials And Methods: The records of patients with angiomyolipoma, as determined by pathological study, from 1998 to 2004 were reviewed by recording patient demographics and outcomes. Fat poor cases were defined as the failure of imaging to demonstrate fat in a lesion.

A case of acute hemolysis after ceftriaxone: immune complex mechanism demonstrated by flow cytometry.

An immune complex mechanism for ceftriaxone sodium- induced severe autoimmune hemolytic anemia has previously been demonstrated using routine blood bank techniques. We describe herein a patient with severe hemolysis that subsided once the drug was discontinued. Serologic techniques demonstrated immune complex-mediated ceftriaxone-dependent red cell antibodies.

Fatal hemorrhagic pneumonia concomitant with Chlamydia pneumoniae and parainfluenza virus 4 infection.

Context: Cases of fatal hemorrhagic pneumonia need to be investigated for highly contagious viral causes. While not all hemorrhagic pneumonias are caused by very contagious agents, the etiology must be correctly determined in order to administer appropriate patient care.

Objective: To determine whether chlamydia, paramyxovirus, or mycoplasma was the causative agent in a case of fatal hemorrhagic pneumonia, and to evaluate the possibility that this was the first case of hantavirus pulmonary syndrome in Illinois.