Analysis of loss of heterozygosity in atypical and negative bile duct brushing cytology specimens with malignant outcome: are "false-negative" cytologic findings a representation of morphologically subtle molecular alterations?

Context: Conventional cytologic evaluation of bile duct brushings for neoplasia has high specificity but relatively low sensitivity.

Objective: The aim of this pilot study was to examine whether K-ras mutations and loss of heterozygosity for multiple microsatellite markers in bile duct brushings would contribute to the detection of malignancy in cases initially reported as "negative" or "atypical."

Design: Bile duct brushing specimens with a negative or an atypical cytologic result (9 cases) had a benign result on the surgical pathology specimen, and 9 additional negative or atypical cases demonstrated adenocarcinoma on the resected surgical specimen.

Determination of sequential mutation accumulation in pancreas and bile duct brushing cytology.

Neoplastic progression is characterized by clonal expansion of tumor cells associated with accumulation of mutational damage. The timing of mutation acquisition could be of value in distinguishing preneoplastic conditions from early and advanced cancer as well as characterizing tumor aggressiveness and treatment response. Using quantitative methods applied to microdissected cell clusters selected according to cytomorphologic features, we sought to demonstrate the feasibility and efficacy for determining the time and course of mutation accumulation in pancreatobiliary cytology specimens.

Molecular alterations in columnar cell lesions of the breast.

Columnar cell lesions of the breast include a morphologic spectrum of simple columnar cell change, columnar cell hyperplasia, columnar cell hyperplasia with atypia and ductal carcinoma in situ of micropapillary/cribriform type. Invasive carcinomas of low grade are often seen in association with this spectrum. The biologic significance of these lesions that are commonly found on breast biopsies is unknown.

The role of pancreatic cyst fluid molecular analysis in predicting cyst pathology.

Background & Aims: Current methods to detect malignancy in mucinous cystic neoplasms of the pancreas remain inadequate. The role of detailed molecular analysis in this context was investigated.

Methods: Endoscopic ultrasound-guided pancreatic cyst aspirates were prospectively collected during a period of 19 months and studied for cytology, carcinoembryonic antigen level, and molecular analysis.

Microdissection-based mutational genotyping of serous borderline tumors of the ovary.

Mutational changes in a number of genetic foci were studied in 12 serous borderline tumors (SBTs) of the ovary including 2 with a micropapillary pattern. The analysis was focused on chromosomal regions that have not been previously studied in these tumors. The findings were correlated with the morphology and the FIGO stage of the tumors.

Use of microsatellite marker loss of heterozygosity in accurate diagnosis of pancreaticobiliary malignancy from brush cytology samples.

Background: Brush cytology of biliary strictures to diagnose pancreaticobiliary malignancy suffers from poor sensitivity.

Aim: To improve the diagnostic yield of pancreaticobiliary brush cytology through analysis of tumour suppressor gene linked microsatellite marker loss of heterozygosity (LOH) and k-ras codon 12 mutation detection.

Methods: Twenty six patients with biliary strictures underwent endoscopic retrograde cholangiography with brush cytology.

Microdissection genotyping of mixed glial and primitive neuroectodermal central nervous system neoplasm.

A 22-year-old man with previous radiation treatment for childhood astrocytoma underwent resection of a right parietooccipital lesion. Histopathology revealed a malignant neoplasm with areas of astrocytic and primitive neuroectodermal components. To resolve the relationship and cellular origin, representative tissue was microdissected from several targets, obtaining a balanced mixture of each element.

Genetic profile of cumulative mutational damage associated with early pulmonary adenocarcinoma: bronchioloalveolar carcinoma vs. stage I invasive adenocarcinoma.

To detect the possible genetic alterations characteristic of bronchioloalveolar carcinoma (BAC) and to study molecular genetic factors responsible for determining the biologic aggressiveness of pulmonary adenocarcinoma, comparative analysis of loss of heterozygosity (LOH) on 9 chromosomal regions was performed in 14 BACs and in 20 stage I adenocarcinomas (AD). The most frequently affected chromosome regions in BAC were 8q and 17p. In stage I AD, more than 60% of the cases showed LOH of 1p, 3p, 5q, 7q, 17p, and 18q loci, and LOH of 1p, 3p, 7q, and 18q was observed with greater frequency than in BAC (P < 0.

Loss of heterozygosity reveals non-VHL allelic loss in hemangioblastomas at 22q13.

Hemangioblastomas (HBs) are low-grade (World Health Organization grade I/IV) central nervous system (CNS) tumors that frequently contain VHL (3p26) mutations. They occur sporadically and in von Hippel Lindau (VHL) disease. Encoded pVHL aids degradation of hypoxia-inducible factors (HIFs) in the presence of normal oxygen levels.

Loss of heterozygosity patterns of sclerosing hemangioma of the lung and bronchioloalveolar carcinoma indicate a similar molecular pathogenesis.

Context: The histogenesis and origin of sclerosing hemangioma (SH) of lung were uncertain for many years. Many immunohistochemical, ultrastructural, and recent molecular studies support the hypothesis that SH is a neoplasm originating from the cells of the terminal lobular unit, similar to the nonmucinous variant of bronchioloalveolar carcinoma (BAC). Most cases of SH are benign, but they can metastasize to the regional lymph nodes.

Microdissection genotyping of gliomas: therapeutic and prognostic considerations.

Molecular anatomic pathology represents the blend of traditional morphological methods and the multigene approach to determine cancer-related gene alterations for diagnostic and prognostic purposes. Microdissection genotyping was utilized to characterize 197 gliomas with targeted microdissection of 2-7 areas spanning the spectrum of histologic types and grades. The methodology described herein is complementary to the existing realities of pathology practice.

Inflammatory fibroid polyps of the gastrointestinal tract: clinical, pathologic, and molecular characteristics.

Inflammatory fibroid polyp (IFP) of the gastrointestinal tract is an uncommon proliferative lesion. When sampled by biopsy, IFP can be mistaken for various lesions, from granulation tissue to high-grade sarcoma. We present an unusual case of IFP and review a large series of IFPs to characterize clinical, histologic, and molecular features of diagnostic value.

Tumor suppressor gene allelic loss profiles of the variants of papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTCa) is a relatively common, indolent tumor that usually has an excellent prognosis. While the diagnosis of conventional PTCa is relatively straightforward, encapsulated tumors with follicular growth pattern and unusual or incomplete cytologic features of papillary carcinoma can be diagnostically challenging. Encapsulated, noninvasive tumors are particularly controversial as the differential diagnosis includes a nonneoplastic nodule, a benign follicular adenoma, and papillary carcinoma.

Absence of Mycobacterium avium subsp. paratuberculosis in the microdissected granulomas of Crohn's disease.

The etiology of Crohn's disease remains unknown with inflammatory, infectious, and/or genetic causes suspected. Granulomatous inflammation is a characteristic feature of the disorder, resembling the tissue response to mycobacterium. Mycobacterium avium subsp.

Microdissection-based genotyping assists discrimination of reactive gliosis from glioma.

We used molecular anatomic pathology to determine the mutational status (loss of heterozygosity [LOH]) to make the distinction between reactive gliosis and glial neoplasia. LOH has been shown to be absent in reactive states and present in neoplastic cellular proliferations. Three groups of patient specimens were analyzed: group 1, reactive gliosis (n = 15); group 2, gliomas of varying histologic type and grade (n = 54); group 3, diagnostically challenging reactive gliosis vs glioma (n = 16).

Allelic loss of tumor suppressor genes in ameloblastic tumors.

Ameloblastoma is an odontogenic tumor with a variety of histologic appearances and an unpredictable biologic behavior. Little is known about allelic losses of tumor suppressor genes in ameloblastomas. This study surveyed DNA damage in ameloblastomas and correlated this with histologic sub-type and clinical outcome.

Microdissection genotyping of archival fixative treated tissue for Gaucher disease.

The genetic diagnosis of Gaucher disease by molecular methods is complicated by the existence of a highly homologous transcribed pseudogene (96% identity) that is found in close proximity to the true gene on chromosome 1q21. In addition, the pseudogene sequence can mimic disease-causing mutations in the true gene. Selective polymerase chain reaction (PCR) amplification of the true gene can be accomplished in extracted DNA from fresh-frozen samples by designing oligonucleotide primers to hybridize to defined regions that are not present in the pseudogene.

Molecular profiling of primary and metastatic neoplasms in the lung using cytologic material obtained by fine-needle aspiration: report of two cases.

Two cases are presented in which molecular analyses of cytologic material obtained by fine-needle aspiration were helpful in establishing relationships between morphologically similar neoplasms in the same patient. For appropriate clinical management, it is important to ascertain whether the tumors represent independent primaries or metastases. Alcohol-fixed cytologic material prepared as cell blocks and formalin-fixed paraffin-embedded tissue were microdissected and analyzed for allelic loss of heterozygosity at multiple preselected genetic loci.

Pulmonary meningothelial-like nodules: a genotypic comparison with meningiomas.

Background: Minute pulmonary meningothelial-like nodules (MPMNs) are incidental interstitial pulmonary nodules. They share histologic, ultrastructural, and immunohistochemical features with meningiomas (MGs).

Design: Sixteen cases yielding 33 separate MPMNs and 10 cases of benign MG were studied.

Correlates of quantitative measurement of BK polyomavirus (BKV) DNA with clinical course of BKV infection in renal transplant patients.

BK virus-allograft nephropathy (BKVAN) is an increasingly recognized complication after kidney transplantation. Quantitative tests have been advocated to monitor patients, but data demonstrating their efficacy are relatively limited. We developed a real-time PCR assay to quantitate BK virus loads in the setting of renal transplantation, and we correlated the BK virus load with clinical course and with the presence of BK virus in renal biopsy specimens.

Molecular analysis to demonstrate that odontogenic keratocysts are neoplastic.

Context: Odontogenic keratocysts (OKCs) are unique odontogenic lesions that have the potential to behave aggressively, that can recur, and that can be associated with the nevoid basal cell carcinoma syndrome. Whether they are developmental or neoplastic continues to be debated.

Objectives: To identify loss of heterozygosity of tumor suppressor genes in OKCs and to suggest a pathogenetic origin for these lesions.

Molecular genotyping of medullary thyroid carcinoma can predict tumor recurrence.

Medullary thyroid carcinoma can have an aggressive behavior, and little is known about the molecular basis for clinical outcome. Defining risk of recurrent or metastatic disease is difficult, and it has been limited to clinical and pathologic features, such as advanced age, cervical lymph node metastases, and stage at presentation. Using microdissection and genotyping, we studied 11 cases of medullary carcinoma for allelic losses in a panel of known tumor suppressor genes.

Comparative molecular analysis of loss of heterozygosity in adenocarcinoma in bile duct brushings and corresponding surgical pathology specimens.

Background: Bile duct brushing is the procedure of choice for the assessment of neoplasia of the biliary and pancreatic ducts. Conventional cytopathologic evaluation has been reported to have high specificity but relatively low sensitivity. Although a number of molecular studies regarding biliary tract tissue specimens have been performed, to the authors' knowledge their precise applicability to cytopathology specimens has not been critically analyzed.

Loss of heterozygosity of the VHL gene identifies malignancy and predicts death in follicular thyroid tumors.

Background: Follicular thyroid tumors (FTT) usually require resection to distinguish adenoma from carcinoma. Better markers that predict histologic subtype and prognosis are needed for FTT.

Methods: Seventeen benign and malignant FTT with follow-up were selected.

Molecular evidence of anaplastic transformation in coexisting well-differentiated and anaplastic carcinomas of the thyroid.

Anaplastic thyroid cancer is a rare but nearly universally fatal tumor. Epidemiologic data suggest that many anaplastic thyroid carcinomas arise from transformation of preexisting or coexisting well-differentiated thyroid carcinomas. At the molecular level, the mutations responsible for the anaplastic transformation are incompletely understood, although the mutational events are thought to involve tumor suppressor genes.