acp. Best practice no 161. Examination of lung specimens

Diagnostic Approach to Life-Threatening Pulmonary Infiltrates

Diagnosis of pulmonary disease is typically based upon consideration of presenting symptoms, physical examination, and pulmonary function testing in combination with classification of radiographic features, to guide diagnostic tests and initiate empiric treatment. When diagnostic efforts and/or empiric treatment fails, thoracic surgeons have traditionally been called upon to perform surgical biopsy of the lung to aid in the diagnosis of indeterminate, life-threatening pulmonary disease. Such biopsy has been requested specifically in the case of diffuse lung disease among patients receiving treatment for solid-organ or hematologic cancers, particularly when symptoms of respiratory failure progress and when noninvasive diagnostic tests and empiric treatments fail to halt progression. In such circumstances, radiologists, pulmonologists, and thoracic surgeons may be consulted and asked to provide tissue specimens that will allow rapid, accurate diagnosis leading to specific treatment. It is imperative that biopsy take place before respiratory failure supervenes [1], and that the specimens provided to clinical laboratories, pathologists, and microbiologists are comprehensive and properly preserved.

Mesothelioma and analysis of tissue fiber content

The strong relationship between mesothelioma and asbestos exposure is well established. The analysis of lung asbestos burden by light and electron microscopy assisted to understand the increased incidence of mesothelioma in asbestos mining and consuming nations.The data on the occupational exposure to asbestos are important information for the purpose of compensation of occupational disease No. 4105 (asbestos-associated mesothelioma) in Germany.However, in many cases the patients have forgotten conditions of asbestos exposure or had no knowledge about the used materials with components of asbestos. Mineral fiber analysis can provide valuable information for the research of asbestos-associated diseases and for the assessment of exposure. Because of the variability of asbestos exposure and long latency periods, the analysis of asbestos lung content is a relevant method for identification of asbestos-associated diseases. Also, sources of secondary exposure, so called "bystander exposition" or environmental exposure can be examined by mineral fiber analysis.Household contacts to asbestos are known for ten patients (1987-2009) in the German mesothelioma register; these patients lived together with family members working in the asbestos manufacturing industry.Analysis of lung tissue for asbestos burden offers information on the past exposure. The predominant fiber-type identified by electron microscopy in patients with mesothelioma is amphibole asbestos (crocidolite or amosite). Latency times (mean 42.5 years) and mean age at the time of diagnose in patients with mesothelioma are increasing (65.5 years). The decrease of median asbestos burden of the lung in mesothelioma patients results in disease manifestation at a higher age.Lung dust analyses are a relevant method for the determination of causation in mesothelioma. Analysis of asbestos burden of the lung and of fiber type provides insights into the pathogenesis of malignant mesothelioma. The most important causal factor for the development of mesothelioma is still asbestos exposure.

Value of F-18-fluorodeoxyglucose positron emission tomography after induction therapy of locally advanced bronchogenic carcinoma

OBJECTIVES

Induction therapy is an important treatment option in locally advanced non-small cell lung cancer. F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) has an important role in initial staging. The aim of this study was to assess the value of FDG-PET in restaging after induction therapy and in analyzing tumor viability, nodal status, distant metastases, and prognosis.

METHODS

Forty-seven patients with locally advanced non-small cell lung cancer accepted for resection after induction therapy underwent FDG-PET. Images were interpreted visually for mediastinal nodal status and metastatic spread. The FDG accumulation in the tumor site was measured by using the maximum standardized uptake value.

RESULTS

Unexpected metastases were detected by means of FDG-PET in 9 patients. Surgical intervention was not performed in 8 patients with confirmed metastases. The rate of unexpected findings increased from complete radiologic remission (0%) over partial remission (9%) to no change (67%). The standardized uptake value was higher in tumors with (n = 26) than in those without (n = 11) histologic proof of viability (6.4 +/- 5.3 vs 2.9 +/- 1.6, P = .006). All patients with standardized uptake values of greater than 5.8 had viable tumors. Sensitivity, specificity, and negative predictive value were 81%, 64%, and 58% for tumor viability and 50%, 88%, and 85% for persistent mediastinal disease. Median survival after resection was greater than 56 months for patients with tumor standardized uptake values of less than 4 and 19 months for patients with standardized uptake values of 4 or greater ( P < .001).

CONCLUSION

FDG-PET helps in the selection of patients for resection after induction therapy. It can be used to detect unexpected distant metastases, especially after poor response to induction therapy. Its high negative predictive value in mediastinal restaging allows for omission of repeat mediastinoscopy. Tumor standardized uptake value after induction is a prognostic factor.

Staging of non-small cell lung cancer: consensus, controversies and challenges

Stage is with performance status, the most potent prognostic factor in non-small cell lung cancer. In the past decades, much effort has been directed towards the definition, description, development and implementation of staging guidelines. This has undoubtedly resulted in improvements in therapy and insight in the biology of the disease. The new millennium sees us confronted with an increasing epidemic of lung cancer. Hence, the need for further improvements in staging accuracy and cost effectiveness, in order to use the available therapeutic armament at its best and provide the patient with a treatment that is best adjusted to his or her condition. Current controversies and future challenges in staging will be addressed.