HepPar-1 expression in primary lung adenocarcinoma

OBJECTIVES

To study a subset of lung adenocarcinomas with aberrant HepPar-1 antigen expression.

METHODS

We performed a clinicopathologic review of 16 cases.

RESULTS

Of 241 primary lung adenocarcinomas tested for expression of the HepPar-1 antigen, 16 (6.6%) were positive. The cases occurred in older smokers with an equal sex distribution. Morphologically, these pulmonary adenocarcinomas had an acinar-predominant architecture, and prominent cribriform growth, with HepPar-1-expressing tumor cells being uniformly columnar with abundant bipolar lightly eosinophilic cytoplasm. HepPar-1 was coexpressed with thyroid transcription factor 1 in 94% of cases. No EGFR mutations were identified, while 31% of cases were positive for KRAS codon 12 mutations.

CONCLUSIONS

Although aberrant HepPar-1 expression was frequently seen in tumors with visceral pleural and angiolymphatic invasion, its prognostic significance is uncertain.

Matrix metalloproteinase-19 is a key regulator of lung fibrosis in mice and humans

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by epithelial phenotypic changes and fibroblast activation. Based on the temporal heterogeneity of IPF, we hypothesized that hyperplastic alveolar epithelial cells regulate the fibrotic response.

OBJECTIVES

To identify novel mediators of fibrosis comparing the transcriptional signature of hyperplastic epithelial cells and conserved epithelial cells in the same lung.

METHODS

Laser capture microscope and microarrays analysis were used to identify differentially expressed genes in IPF lungs. Bleomycin-induced lung fibrosis was evaluated in Mmp19-deficient and wild-type (WT) mice. The role of matrix metalloproteinase (MMP)-19 was additionally studied by transfecting the human MMP19 in alveolar epithelial cells.

MEASUREMENTS AND MAIN RESULTS

Laser capture microscope followed by microarray analysis revealed a novel mediator, MMP-19, in hyperplastic epithelial cells adjacent to fibrotic regions. Mmp19(-/-) mice showed a significantly increased lung fibrotic response to bleomycin compared with WT mice. A549 epithelial cells transfected with human MMP19 stimulated wound healing and cell migration, whereas silencing MMP19 had the opposite effect. Gene expression microarray of transfected A549 cells showed that PTGS2 (prostaglandin-endoperoxide synthase 2) was one of the highly induced genes. PTGS2 was overexpressed in IPF lungs and colocalized with MMP-19 in hyperplastic epithelial cells. In WT mice, PTGS2 was significantly increased in bronchoalveolar lavage and lung tissues after bleomycin-induced fibrosis, but not in Mmp19(-/-) mice. Inhibition of Mmp-19 by siRNA resulted in inhibition of Ptgs2 at mRNA and protein levels.

CONCLUSIONS

Up-regulation of MMP19 induced by lung injury may play a protective role in the development of fibrosis through the induction of PTGS2.

Asthmatic granulomatosis: a novel disease with asthmatic and granulomatous features

RATIONALE

Severe asthma represents 5-10% of all asthma, yet remains problematic and poorly understood. Although it is increasingly recognized as consisting of numerous heterogenous phenotypes, their immunopathology, particularly in the distal airways and interstitium, remains poorly described.

OBJECTIVES

To identify the pathobiology of atypical difficult asthma.

METHODS

We report 10 from a total of 19 patients (17 women and 2 men) meeting asthma and severe asthma definitions, requiring daily systemic corticosteroid (CS) use, with inconsistent abnormalities on chest computed tomography scans, who underwent video-assisted thoracoscopic biopsies for further diagnosis and management.

MEASUREMENTS AND MAIN RESULTS

The pathology of 10 of the 19 cases revealed small airway changes consistent with asthma (eosinophilia, goblet cell hyperplasia), but with the unexpected finding of interstitial nonnecrotizing granulomas. These patients had no evidence for hypersensitivity pneumonitis, but 70% of cases had a personal or family history of autoimmune-like disease. The 10 cases were treated with azathioprine, mycophenolic acid, methotrexate, or infliximab. Nine of 10 showed decreased CS requirements and improved or maintained FEV(1) despite lower CS doses. Of the remaining nine patients, six manifested asthmatic small airway disease, alone or in combination with alveolar septal mononuclear cells, but no granulomas, whereas three manifested other pathologic findings (aspiration, pneumonia, or thromboemboli).

CONCLUSIONS

These data suggest that a subset of severe "asthma" manifests a granulomatous pathology, which we term "asthmatic granulomatosis." Although identification of this disease currently requires a thorascopic biopsy, alternative approaches to therapy lead to improvement in outcomes.

Numerical fidelity of endoscopic biopsy fragments in the processing sequence of a university surgical pathology laboratory

CONTEXT

Diagnostic specimens in surgical pathology are, in general, becoming smaller and smaller, as minimally invasive surgical procedures are used to obtain representative tissue. Conservation and effective utilization of small biopsy tissue is therefore crucial in the pathology laboratory.

OBJECTIVE

To identify potential areas where biopsy tissue may be lost in the course of processing in our university-based laboratory.

DESIGN

We followed 2934 endoscopic biopsy samples as they moved through our grossing area and histology laboratory by documenting the number of fragments inked and placed within tissue paper at the time of gross assessment, the number of fragments found in each cassette after processing and subsequently embedded in paraffin, and the number of pieces of tissue present on glass slides after staining.

RESULTS

In 805 (27.4%) cases, the number of fragments of tissue noted on glass slides containing 2 levels of the paraffin block differed from the number submitted in the tissue cassette. Of these, most (137, 17%) differed between the number of fragments embedded in paraffin and those identified on glass slides. Loss of tissue fragments occurred in only 7.2% of cases, while 26.3% had gains in tissue fragments.

CONCLUSIONS

Recognition of type(s) and source(s) of variation in biopsy fragment numbers is important in quality control and in the overall practical management of a histology laboratory.

Adenosquamous carcinoma of the lung: a microdissection study of KRAS and EGFR mutational and amplification status in a western patient population

Molecular testing of pulmonary adenocarcinomas for EGFR and KRAS mutations is becoming more common as tyrosine kinase inhibitor therapy is used for EGFR-mutated adenocarcinomas. Adenosquamous carcinomas represent a hybrid carcinoma, and there is no literature addressing the frequency of EGFR and KRAS mutations in this subset of lung carcinomas in Western populations. For this study, 23 adenosquamous carcinomas were microdissected with the glandular and squamous components analyzed for EGFR and KRAS mutations and EGFR amplification. In 3 cases (13%), there were EGFR mutations, with 2 having the identical mutation in the glandular and squamous elements. In 3 cases (13%), there were KRAS mutations in both histologic elements. Great heterogeneity existed in the rates of EGFR amplification in the 2 histologic components. Amplification was most common in both glandular and squamous components (11/23 [48%]). EGFR mutations occur in adenosquamous carcinoma in the same percentages as in conventional adenocarcinoma in the Western population. KRAS mutations are less common.

Increased levels of tumor-infiltrating lymphocytes are associated with improved recurrence-free survival in stage 1A non-small-cell lung cancer

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have been found to increase survival in many forms of cancer, including, endometrial, bile ductal, colonic, esophageal, and urothelial cancers, as well as melanoma and follicular lymphoma. The relevance of TILs in the prognosis of non-small-cell lung cancer (NSCLC), however, still remains controversial. We compared the outcomes of stage 1A NSCLC with and without tumor infiltrating lymphocytes to evaluate the effects of TILs on recurrence and survival patterns.

MATERIALS AND METHODS

From 2000 to 2009, 273 anatomic segmentectomies and lobectomies were performed on stage 1A NSCLC. Patients were stratified into TIL- and TIL+ cohorts based on pathologic evaluation. Further investigation was conducted on the effects of TILs in patients with and without angiolymphatic invasion. Variables analyzed include overall survival, recurrence-free survival, and type of recurrence.

RESULTS

Overall 5-y survival was not affected by TIL status (65% versus 60%, P = 0.469). Five-year recurrence-free survival (RFS) was significantly increased in the TIL+ group versus the TIL- group (87% versus 73%, P = 0.011), most significantly in women (P = 0.016). The presence of angiolymphatic invasion (ALI) was associated with decreased 5-y RFS versus patients without ALI (61% versus 85%, P < 0.001). Interestingly, in the ALI negative group, TIL+ patients experienced a significantly increased 5-y recurrence-free survival versus TIL- patients (93% versus 80%, P = 0.036).

CONCLUSIONS

High levels of intratumoral TILs are associated with improved recurrence-free survival in stage 1A NSCLC patients as well as a reduced likelihood of systemic recurrence. When angiolymphatic invasion is not present, the beneficial effects of TILs become even more profound.

Prognostic significance of CD44 expression in adenocarcinoma of the lung

Aims-To determine whether expression of CD44 in neoplasia is associated with tumour grade, stage and prognosis.Methods-The immunohistochemical expression of CD44 was evaluated using the mouse antihuman monoclonal antibody 3G12 which recognises regions shared by all CD44 isoforms to determine whether expression in formalin fixed, paraffin wax embedded tissue correlates with tumour grade, stage or survival in adenocarcinoma of the lung. Thirty one adenocarcinomas of the lung, 16 T2N0 and 15 T2N1, and their nodal metastases were studied.Results-Of the 31 tumours, 25 were positive for the CD44 antigen. CD44 expression correlated with tumour grade, in that intense staining was seen only in moderately and/or poorly differentiated tumours. CD44 did not correlate with nodal status, tumour size, pleural invasion, angiolymphatic invasion, or host inflammatory response, but did correlate with survival. A median survival of 46 months was observed in patients with moderate to strong CD44 expression compared with 24 months for those with no or weak expression. Nine patients were alive without evidence of disease at a median follow up of 61 months. Six (66%) of these nine patients had strong CD44 expression. This contrasts with strong expression in only three (17%) of the 17 patients dying with a median survival of 28 months.Conclusion-In primary adenocarcinoma of the lung loss of CD44 expression is associated with less favorable outcome and may indicate a more aggressive neoplasm. CD44 may be a useful prognostic marker in lung carcinoma.

The development and testing of a laboratory information system-driven tool for pre-sign-out quality assurance of random surgical pathology reports

We describe the development and testing of a novel pre-sign-out quality assurance tool for case diagnoses that allows for the random review of a percentage of cases by a second pathologist before case verification and release of the final report. The tool incorporates the ability to record and report levels of diagnostic disagreement, reviewers' comments, and steps taken to resolve any discrepancies identified. It is expandable to allow for the review of any percentage of cases in any number of subspecialty or general pathology "benches" and provides a prospective instrument for preventing some serious errors from occurring, thereby potentially affecting patient care in addition to identifying and documenting more general process issues. It can also be used to augment other more conventional methods of quality control such as frozen section/final diagnosis correlation, conference review, and case review before interdisciplinary clinicopathologic sessions. There has been no significant delay in case turnaround time since implementation. Further assessment of the tool's function after full departmental application is underway.

Inhibition and role of let-7d in idiopathic pulmonary fibrosis

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and usually lethal fibrotic lung disease characterized by profound changes in epithelial cell phenotype and fibroblast proliferation.

OBJECTIVES

To determine changes in expression and role of microRNAs in IPF.

METHODS

RNA from 10 control and 10 IPF tissues was hybridized on Agilent microRNA microarrays and results were confirmed by quantitative real-time polymerase chain reaction and in situ hybridization. SMAD3 binding to the let-7d promoter was confirmed by chromatin immunoprecipitation, electrophoretic mobility shift assay, luciferase assays, and reduced expression of let-7d in response to transforming growth factor-beta. HMGA2, a let-7d target, was localized by immunohistochemistry. In mice, let-7d was inhibited by intratracheal administration of a let-7d antagomir and its effects were determined by immunohistochemistry, immunofluorescence, quantitative real-time polymerase chain reaction, and morphometry.

MEASUREMENTS AND MAIN RESULTS

Eighteen microRNAs including let-7d were significantly decreased in IPF. Transforming growth factor-beta down-regulated let-7d expression, and SMAD3 binding to the let-7d promoter was demonstrated. Inhibition of let-7d caused increases in mesenchymal markers N-cadherin-2, vimentin, and alpha-smooth muscle actin (ACTA2) as well as HMGA2 in multiple epithelial cell lines. let-7d was significantly reduced in IPF lungs and the number of epithelial cells expressing let-7d correlated with pulmonary functions. HMGA2 was increased in alveolar epithelial cells of IPF lungs. let-7d inhibition in vivo caused alveolar septal thickening and increases in collagen, ACTA2, and S100A4 expression in SFTPC (pulmonary-associated surfactant protein C) expressing alveolar epithelial cells.

CONCLUSIONS

Our results indicate a role for microRNAs in IPF. The down-regulation of let-7d in IPF and the profibrotic effects of this down-regulation in vitro and in vivo suggest a key regulatory role for this microRNA in preventing lung fibrosis. Clinical trial registered with www.clinicaltrials.gov (NCT 00258544).

Gene expression profiles of acute exacerbations of idiopathic pulmonary fibrosis

RATIONALE

The molecular mechanisms underlying acute exacerbations of idiopathic pulmonary fibrosis (IPF) are poorly understood. We studied the global gene expression signature of acute exacerbations of IPF.

OBJECTIVES

To understand the gene expression patterns of acute exacerbations of IPF.

METHODS

RNA was extracted from 23 stable IPF lungs, 8 IPF lungs with acute exacerbation (IPF-AEx), and 15 control lungs and used for hybridization on Agilent gene expression microarrays. Functional analysis of genes was performed with Spotfire and Genomica. Gene validations for MMP1, MMP7, AGER, DEFA1-3, COL1A2, and CCNA2 were performed by real-time quantitative reverse transcription-polymerase chain reaction. Immunohistochemistry and in situ terminal deoxynucleotidyltransferase dUTP nick end-labeling assays were performed on the same tissues used for the microarray. ELISA for alpha-defensins was performed on plasma from control subjects, patients with stable IPF, and patients with IPF-AEx.

MEASUREMENTS AND MAIN RESULTS

Gene expression patterns in IPF-AEx and IPF samples were similar for the genes that distinguish IPF from control lungs. Five hundred and seventy-nine genes were differentially expressed (false discovery rate < 5%) between stable IPF and IPF-AEx. Functional analysis of these genes did not indicate any evidence of an infectious or overwhelming inflammatory etiology. CCNA2 and alpha-defensins were among the most up-regulated genes. CCNA2 and alpha-defensin protein levels were also higher and localized to the epithelium of IPF-AEx, where widespread apoptosis was also detected. alpha-Defensin protein levels were increased in the peripheral blood of patients with IPF-AEx.

CONCLUSIONS

Our results indicate that IPF-AEx is characterized by enhanced epithelial injury and proliferation, as reflected by increases in CCNA2 and alpha-defensins and apoptosis of epithelium. The concomitant increase in alpha-defensins in the peripheral blood and lungs may suggest their use as biomarkers for this disorder.

Micropapillary lung adenocarcinoma: EGFR, K-ras, and BRAF mutational profile

Micropapillary lung adenocarcinoma (MPA) has been reported as an aggressive variant of adenocarcinoma, frequently manifesting at high stage with a poor prognosis. We analyzed the clinical and molecular profile of 15 primary MPAs for K-ras, EGFR, and BRAF mutations and performed fluorescence in situ hybridization for EGFR amplification. In our study, 11 (73%) of 15 MPAs harbored mutually exclusive mutations: 5 (33%) K-ras, 3 (20%) EGFR, and 3 (20%) BRAF. Mutations in all 3 genes occurred in patients with a smoking history and tumors with mucinous differentiation and secondary lepidic, acinar, and solid growth, suggesting that in a Western population, cytomorphologic correlation with genetic mutations is more unpredictable than in Japanese cohorts. We conclude that K-ras, EGFR, and BRAF mutations are disproportionately seen in adenocarcinomas of lung with a dominant micropapillary growth pattern compared with conventional adenocarcinoma in our institutional experience.

Mammalian mastermind like 2 11q21 gene rearrangement in bronchopulmonary mucoepidermoid carcinoma

The translocation t(11;19)(q21;p13) results in the gene fusion of mucoepidermoid carcinoma translocated 1-mammalian mastermind like 2 genes that is the major chromosomal abnormality observed in mucoepidermoid carcinomas of salivary glands but has not been studied in bronchopulmonary mucoepidermoid carcinoma. To investigate the importance of the mammalian mastermind like 2 gene rearrangement and mucoepidermoid carcinoma translocated 1-mammalian mastermind like 2 fusion gene in bronchopulmonary mucoepidermoid carcinoma tumorigenesis and its differential diagnosis with primary pulmonary non-small-cell carcinomas, we evaluated the presence of the mammalian mastermind like 2 gene rearrangement and the mucoepidermoid carcinoma translocated 1-mammalian mastermind like 2 fusion in formalin-fixed, paraffin-embedded tissue sections from 17 adult bronchopulmonary mucoepidermoid carcinoma, 16 adenosquamous carcinomas, 24 squamous cell carcinomas, and 41 primary adenocarcinomas by fluorescence in situ hybridization and reverse transcriptase polymerase chain reaction. We detected mammalian mastermind like 2 gene rearrangement by fluorescence in situ hybridization analysis in 13 (77%) of 17 bronchopulmonary mucoepidermoid carcinoma cases (10 of 10 being low grade and 3 of 7 being high grade). Reverse transcriptase polymerase chain reaction analysis confirmed positive fluorescence in situ hybridization results in 6 (43%) of 14 mucoepidermoid carcinoma cases. None of the squamous, adenosquamous, or adenocarcinoma cases revealed the mammalian mastermind like 2 gene rearrangement by fluorescence in situ hybridization, and the mucoepidermoid carcinoma translocated 1-mammalian mastermind like 2 fusion product by reverse transcriptase polymerase chain reaction was not identified specifically in our adenosquamous carcinoma cases. In conclusion, our study demonstrates that mammalian mastermind like 2 gene rearrangement and mucoepidermoid carcinoma translocated 1-mammalian mastermind like 2 fusion product can be detected by fluorescence in situ hybridization and reverse transcriptase polymerase chain reaction analysis performed on low- and high-grade primary bronchopulmonary mucoepidermoid carcinoma and can be used to help discriminate low- and high-grade mucoepidermoid carcinoma from adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma mimics in histologically challenging cases.

Egr-1 regulates autophagy in cigarette smoke-induced chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by abnormal cellular responses to cigarette smoke, resulting in tissue destruction and airflow limitation. Autophagy is a degradative process involving lysosomal turnover of cellular components, though its role in human diseases remains unclear.

METHODOLOGY AND PRINCIPAL FINDINGS

Increased autophagy was observed in lung tissue from COPD patients, as indicated by electron microscopic analysis, as well as by increased activation of autophagic proteins (microtubule-associated protein-1 light chain-3B, LC3B, Atg4, Atg5/12, Atg7). Cigarette smoke extract (CSE) is an established model for studying the effects of cigarette smoke exposure in vitro. In human pulmonary epithelial cells, exposure to CSE or histone deacetylase (HDAC) inhibitor rapidly induced autophagy. CSE decreased HDAC activity, resulting in increased binding of early growth response-1 (Egr-1) and E2F factors to the autophagy gene LC3B promoter, and increased LC3B expression. Knockdown of E2F-4 or Egr-1 inhibited CSE-induced LC3B expression. Knockdown of Egr-1 also inhibited the expression of Atg4B, a critical factor for LC3B conversion. Inhibition of autophagy by LC3B-knockdown protected epithelial cells from CSE-induced apoptosis. Egr-1(-/-) mice, which displayed basal airspace enlargement, resisted cigarette-smoke induced autophagy, apoptosis, and emphysema.

CONCLUSIONS

We demonstrate a critical role for Egr-1 in promoting autophagy and apoptosis in response to cigarette smoke exposure in vitro and in vivo. The induction of autophagy at early stages of COPD progression suggests novel therapeutic targets for the treatment of cigarette smoke induced lung injury.

Revision of the 1996 working formulation for the standardization of nomenclature in the diagnosis of lung rejection

In 1990, an international grading scheme for the grading of pulmonary allograft rejection was adopted by the International Society for Heart and Lung Transplantation (ISHLT) and was modified in 1995 by an expanded group of pathologists. The original and revised classifications have served the lung transplant community well, facilitating communication between transplant centers with regard to both patient management and research. In 2006, under the direction of the ISHLT, a multi-disciplinary review of the biopsy grading system was undertaken to update the scheme, address inconsistencies of use, and consider the current knowledge of antibody-mediated rejection in the lung. This article summarizes the revised consensus classification of lung allograft rejection. In brief, acute rejection is based on perivascular and interstitial mononuclear infiltrates, Grade A0 (none), Grade A1 (minimal), Grade A2 (mild), Grade A3 (moderate) and Grade A4 (severe), as previously. The revised (R) categories of small airways inflammation, lymphocytic bronchiolitis, are as follows: Grade B0 (none), Grade B1R (low grade, 1996, B1 and B2), Grade B2R (high grade, 1996, B3 and B4) and BX (ungradeable). Chronic rejection, obliterative bronchiolitis (Grade C), is described as present (C1) or absent (C0), without reference to presence of inflammatory activity. Chronic vascular rejection is unchanged as Grade D. Recommendations are made for the evaluation of antibody-mediated rejection, recognizing that this is a controversial entity in the lung, less well developed and understood than in other solid-organ grafts, and with no consensus reached on diagnostic features. Differential diagnoses of acute rejection, airway inflammation and chronic rejection are described and technical considerations revisited. This consensus revision of the working formulation was approved by the ISHLT board of directors in April 2007.

Bronchioloalveolar carcinoma: a review of current concepts and evolving issues

CONTEXT

The concept of bronchioloalveolar carcinoma underwent considerable refinement between the publications of the 1981 and 1999 World Health Organization classifications of lung tumors. Both pathologic and clinical aspects of this carcinoma are the subject of considerable interest.

OBJECTIVE

To review and summarize the evolution of the current concept of bronchioloalveolar carcinoma and evolving issues that are under further investigation.

DATA SOURCES

Pertinent peer-reviewed literature emphasizing historical classification and evolution as well as current and evolving concepts.

CONCLUSIONS

Small, solitary, nonmucinous bronchioloalveolar carcinomas are associated with a markedly better prognosis compared with conventional invasive adenocarcinomas. Such tumors may be cured by surgical resection and may be more responsive to epidermal growth factor receptor-targeted therapy. The prognosis and staging of multifocal disease remain unresolved, as does the question of whether a small amount of invasion adversely affects prognosis. Mucinous bronchioloalveolar carcinoma appears to be a markedly different entity than the nonmucinous subtype.

Microsatellite instability is uncommon in lymphoepithelioma-like carcinoma of the lung

Primary lymphoepithelioma-like carcinoma of the lung (LELC) shares some morphologic and clinical characteristics with malignancies associated with microsatellite instability (MSI). The aims of our study were to determine the MSI status in LELC and compare these findings with stage I non-small cell lung carcinoma (NSCLC) with marked lymphocytic host response (MLHR). We assessed MSI by a DNA-based polymerase chain reaction assay using mononucleotide (BAT25 and BAT26) and dinucleotide (D2S123, D5S346, and D17S250) repeats. MSI was detected in 2 (29%) of 7 LELC cases with only 1 marker (D17S250), and in 3 (19%) of 16 NSCLC cases with MLHR with only 2 markers (1D2S123 and 2 D17S250). Loss of heterozygosity (LOH) was detected at 1 or 2 of 3 dinucleotide repeats in 11 NSCLC cases (69%) with MLHR and 3 LELC cases (43%) (P = .36). The overall frequencies of LOH in NSCLC with MLHR were 29% and 19% in LELC (P = .55). MSI is very uncommon in LELC, indicating that MSI is not an important event in carcinogenesis for this tumor subtype. The presence of LOH suggests a probable role of tumor suppressor genes in LELC carcinogenesis.

Respiratory bronchiolitis-associated interstitial lung disease with fibrosis is a lesion distinct from fibrotic nonspecific interstitial pneumonia: a proposal

Nine cases of clinical and radiographic chronic interstitial lung disease are presented that have features of respiratory bronchiolitis-associated interstitial lung disease, but were associated with a respiratory bronchiolitis having extensive paucicellular lamellar eosinophilic collagenous thickening of alveolar septa in a patchy, particularly subpleural distribution. Patients were middle-aged with shortness of breath, mixed obstructive and restrictive lung disease with markedly reduced diffusing capacity and radiographs demonstrating centrilobular micronodules, occasional ground glass opacities and emphysema. All were alive at follow-up. The morphology of this process raises the differential diagnosis with the fibrotic form of nonspecific interstitial pneumonia and highlights the role of cigarette smoking as a potential cause of fibrotic lung disease.

A combination of molecular markers accurately detects lymph node metastasis in non-small cell lung cancer patients

Occult lymph node metastasis (micrometastasis) is a good prognostic indicator in non-small cell lung cancer (NSCLC) and could be used to direct adjuvant chemotherapy in stage I patients. This study was designed to evaluate molecular markers for detection of occult lymph node metastasis in NSCLC, define the best marker or marker combination to distinguish positive from benign lymph nodes, and evaluate these markers in lymph nodes from pathologically node-negative (pN(0)) NSCLC patients. Potential markers were identified through literature and database searches and all markers were analyzed by quantitative reverse transcription-PCR in a primary screen of six NSCLC specimens and 10 benign nodes. Selected markers were further evaluated on 21 primary NSCLC specimens, 21 positive nodes, and 21 benign nodes, and the best individual markers and combinations were identified. A combination of three markers was further validated on an independent set of 32 benign lymph nodes, 38 histologically positive lymph nodes, and 462 lymph nodes from 68 pN(0) NSCLC patients. Forty-two markers were evaluated in the primary screen and eight promising markers were selected for further analysis. A combination of three markers (SFTPB, TACSTD1, and PVA) was identified that provided perfect classification of benign and positive nodes in all sample sets. PVA and SFTPB are particularly powerful in tumors of squamous and adenocarcinoma histologies, respectively, whereas TACSTD1 is a good general marker for NSCLC metastasis. The combination of these genes identified 32 of 462 (7%) lymph nodes from 20 of 68 (29%) patients as potentially positive for occult metastasis. Long-term follow-up will determine the clinical relevance of these findings.

Significance of a solitary perivascular mononuclear infiltrate in lung allograft recipients with mild acute cellular rejection

BACKGROUND

Although a solitary prominent perivascular mononuclear infiltrate is diagnostic of mild acute rejection (A2) in lung allograft recipients, its significance is still poorly defined. We evaluated the significance of a solitary perivascular mononuclear infiltrate and its correlation with clinical outcome in lung allograft recipients.

METHODS

Thirteen patients had mild acute rejection as diagnosed by the presence of a solitary perivascular mononuclear infiltrate. The patients were divided into 2 groups based on subsequent treatment: treated (Group 1) and non-treated (Group 2) patients. We analyzed the difference between the 2 groups according to clinical presentation, histologic parameters and outcome.

RESULTS

Nine patients were women (69%), 4 were men (31%); 12 were white and 1 was African American. Ages at the time of biopsy ranged from 20 to 68 years, with a mean of 47.2 years and a median of 52 years. Eight had a history of single-lung transplant and 5 had a history of double-lung transplant. The most common reasons for transplantation were emphysema (n = 6) and cystic fibrosis (n = 3). Nine patients (65.4%) showed decreased rejection grade or no evidence of acute rejection (Group 1) after treatment. Four patients who were untreated had persistent multifocal mild or worsening moderate rejection on subsequent biopsy (Group 2).

CONCLUSIONS

Treated and untreated patients with mild rejection based on a solitary perivascular infiltrate have similar clinical presentations and histologic characteristics. Solitary mononuclear infiltrates showed persistence or progression without therapy and therefore need to be treated as, not segregated from, the "usual" forms of mild acute allograft rejection.