Lung mass
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Lung Mass Microchapters |
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Treatment |
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Lung mass On the Web |
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American Roentgen Ray Society Images of Lung mass |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Akshun Kalia M.B.B.S.[2]Maria Fernanda Villarreal, M.D. [3]
Synonyms and keywords:Pulmonary mass
Overview
Lung mass (also known as "Pulmonary mass") is defined as any area of pulmonary opacification that measures more than 30 mm (3 cms) in the lung. Lung mass are abnormal growths found in the lung which can be either be benign or malignant. The most common cause of a pulmonary mass is lung cancer. Other causes of lung mass include granuloma, lipoma, tuberculosis, and aspergillosis. Lung mass may be classified according to the location, imaging features, size, and distribution. The incidence rate of lung mass is approximately 58 per 100 000 individuals in the United States.[1] The incidence of lung mass increases with age; the median age at diagnosis is between 35 to 75 years. Lung mass has a wide age distribution. However, the majority of these lesions are more often diagnosed in adults. Males are more commonly affected with lung mass than females with male to female ratio of 2:1. There is no racial predilection for lung mass.[2] The most common symptom of a lung mass is cough, which will gradually persist over time. Other symptoms may include dyspnea, hemoptysis, chronic coughing, wheezing, and chest pain. In some cases, lung mass may be asymptomatic. A vital feature in the evaluation of lung mass includes malignancy assessment. The evaluation approach of lung mass starts with initial morphological evaluation of the mass (size, margins, contours, and growth). Other characteristics, such as: location, clinical features, and distribution may be helpful for the therapeutical management, surveillance, and follow-up of lung mass. Lung mass can be divided into 2 categories: benign pulmonary mass and malignant pulmonary mass. Based upon these categories, complementary diagnostic studies and management, include: PET/CT scan, CT scan, non-surgical biopsy, and surgical resection.[3]
Historical Perspective
The first reported case of lung mass dates back to early 1400s when around 50% of miners in Germany and Czech Republic died of a pulmonary disease called Bergkrankheit.[4] *In 1929, German physician, Fritz Lickint published a paper and suggested that lung mass patients were likely to be smokers and launched anti tobacco campaign in Germany.In 1950's, United States physician Cuyler Hammond and Ernest Wynder provided additional corroboration for a causal association between smoking and lung cancer.
Classification
Lung mass may be classified on the basis of histopathology into two types such as malignant or benign. In addition, lung mass can be sub-classified according to the location, imaging features, size, and distribution.
| Lung mass | |||||||||||||||||||||||||||||||||||
| Location | Histology | Imaging Features | |||||||||||||||||||||||||||||||||
| •Pleural •Endobronchial •Parenchymal | •Malignant mass •Benign mass | •Hyperdense pulmonary mass •Cavitating pulmonary mass | |||||||||||||||||||||||||||||||||
Pathophysiology
It is thought that lung mass is the result of genetic and environmental factors. Genes involved in the pathogenesis of lung mass include mutations in K-ras oncogene and TP53 tumor-suppressor gene. Other genes include mutation in EML4-ALK, PIK3CA, c-MET, NKX2-1, LKB1 and BRAF kinase. Environmental factors include smoking (most important carcinogen), radon, asbestos, viral infections, and states of chronic lung inflammation, all of which may predispose to cellular damage and DNA mutations that predispose to the development of lung mass.
Causes
The most common cause of a pulmonary mass is lung cancer. Other causes include hamartomas, Hodgkin's lymphoma, pleural malignant mesothelioma, metastasis, granuloma, lipoma, tuberculosis, and aspergillosis.[5]
Differential Diagnosis
Lung mass must be differentiated from other causes that cause cough, chest pain, or wheezing such as primary lung cancer, pulmonary abscess, granulomas, tuberculosis, and metastases.[6]
Epidemiology and Demographics
The incidence of lung mass is approximately 58 per 100 000 individuals in the United States. The incidence of lung masses increases with age; the median age at diagnosis is between 35 to 75 years. Males are more commonly affected with lung masses than females with male to female ratio of 2:1. There is no racial predilection for lung mass.[2]
Screening
According to the U.S. Preventive Services Task Force (USPSTF) there is sufficient evidence to recommend routine screening for lung mass. Screening for suspected lung cancer by low-dose computed tomography is recommended every year among smokers who are between 55 to 80 years old and who have history of smoke 30 pack-years or more and either continue to smoke or have quit within the past 15 years (grade B recommendation).[1][7]
Diagnosis
Evaluation of Lung Mass
A vital feature in the evaluation of lung mass includes malignancy assessment. The evaluation approach of lung mass depends upon the initial morphological findings of the mass such as size, margins, contours, and growth. Other characteristics such as location, clinical features, and distribution may be helpful in the therapeutical management, surveillance, and follow-up of the lung mass. Lung mass can be divided into two categories such as benign pulmonary mass and malignant pulmonary mass. Based upon these categories, complementary diagnostic studies and management include PET/CT scan, non-surgical biopsy, and surgical resection. The following algorithm outlines the various steps involved in the assessment of a lung mass. [2]
| Lung opacity on Chest X ray (CXR) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Size >3 cms; classified as lung mass | Size <3 cms; classified as pulmonary nodule | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| High resolution chest CT scan | Check previous CXR | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Imaging features | Previous CXR normal; suggesting new growth | Previous CXR shows opacity but stable in size since then | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Hyperdense pulmonary mass ❑Internal/eccentric calcification | Cavitating pulmonary mass ❑ Gas-filled area ❑ Thick/spiculated wall (must be greater than 2-5 mm) | Follow up every 2-3 yrs | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Other diagnostic studies ❑ Sputum cytology ❑ Endobronchial ultrasound ❑ Endoscopic ultrasound ❑ Bronchoscopy ❑ Mediastinoscopy | High resolution chest CT scan | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Highly suspicious for malignancy •Age >60yrs •Current smoker •Size >2cms | Suspicious for malignancy •Age 40-60yrs •Current smoker •Size 0.8-2cms | Benign features •Age <40yrs •Non smoker •Size <0.8cm | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| PET or biopsy | Serial CT scans | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| PET with biopsy | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Malignancy | No evidence of malignancy | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Surgical excision/Chemo depending upon histopathology | No growth over time | Lesion grows over time | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Surgical excision/Chemo depending upon histopathology | Serial CT scans | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| No further workup | PET with or biopsy | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Surgical excision/Chemo depending upon histopathology | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Staging
According to the American Joint Committee on Cancer (AJCC) staging system, there are 4 stages of malignant lung mass, based on 3 factors: tumor size, lymph node invasion, and metastasis. Each stage is assigned a letter and a number that designate T for tumor size, N for node invasion, and M for metastasis.[8]
History and Symptoms
The most common symptom of a lung mass is cough, which will gradually persist over time. Other symptoms may include: dyspnea, hemoptysis, wheezing, and chest pain. A positive history of smoking, exposure to asbestos, tuberculosis infection, or a high risk occupation may be suggestive of a lung mass. Symptoms related with lung mass will vary depending on the size and location of the tumor. Common symptoms of lung mass may also include loss of appetite, fatigue, and cachexia.[9][10]
Physical Examination
Physical examination findings of lung mass will depend on the location of the tumor. Lung mass with central location may cause crackling sounds, focal wheezing, voice hoarseness, and tachypnea. Lung mass with peripheral location can present with pleurisy findings, such as reduced chest expansion. Common physical examination of patients with lung mass, include: crackling or bubbling noises, decreased/absent breath sounds, and whispered pectoriloquy.[11]
Laboratory Studies
Laboratory findings associated with lung mass, include: complete blood count, electrolytes, calcium, alkaline phosphatase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, creatinine, albumin, serum immunoglobulin E, and lactate dehydrogenase.[3]
Biopsy
Biopsy for lung mass may be classified into 2 categories: non-surgical biopsy and surgical biopsy. Biopsy findings associated with lung mass will depend on tumor histology. Common types of lung tissue biopsy for pulmonary mass, include: conventional bronchoscopic-guided transbronchial biopsy, bronchoscopic-transbronchial needle aspiration, endobronchial ultrasound-guided sheath transbronchial biopsy, and endobronchial ultrasound-guided transbronchial needle aspiration. Common indications for biopsy in lung mass, include: suspected lung cancer, malignant features (lymph node involvement).[12][13]
Diagnosis
Evaluation of Lung Mass | History and Symptoms | Physical Examination | Imaging | Laboratory Findings | Biopsy
External Links
- ↑ 1.0 1.1 National Lung Screening Trial. Wikipedia. https://en.wikipedia.org/wiki/National_Lung_Screening_Trial Accessed on February 4,2016
- ↑ 2.0 2.1 2.2 Littleton JT, Durizch ML, Moeller G, Herbert DE (1990). "Pulmonary masses: contrast enhancement". Radiology. 177 (3): 861–71. doi:10.1148/radiology.177.3.2244002. PMID 2244002.
- ↑ 3.0 3.1 Spira A, Ettinger DS (2004). "Multidisciplinary management of lung cancer". N. Engl. J. Med. 350 (4): 379–92. doi:10.1056/NEJMra035536. PMID 14736930.
- ↑ Witschi H (2001). "A short history of lung cancer". Toxicological Sciences : an Official Journal of the Society of Toxicology. 64 (1): 4–6. PMID 11606795. Retrieved 2011-12-09. Unknown parameter
|month=ignored (help) - ↑ Gadkowski LB, Stout JE (2008). "Cavitary pulmonary disease". Clin. Microbiol. Rev. 21 (2): 305–33, table of contents. doi:10.1128/CMR.00060-07. PMC 2292573. PMID 18400799.
- ↑ Bhatia K, Ellis S (2006). "Unusual lung tumours: an illustrated review of CT features suggestive of this diagnosis". Cancer Imaging. 6: 72–82. doi:10.1102/1470-7330.2006.0013. PMC 1693761. PMID 16829468.
- ↑ Davis AM, Cifu AS. Lung Cancer Screening. JAMA. 2014;312(12):1248-1249. doi:10.1001/jama.2014.12272.
- ↑ Stages of non–small cell lung cancer. Canadian Cancer Society. http://www.cancer.ca/en/cancer-information/cancer-type/lung/staging/?region=ab
- ↑ Non small cell lung cancer. Wikipedia. https://en.wikipedia.org/wiki/Non-small-cell_lung_carcinoma Accessed on February 24, 2016
- ↑ Raz DJ, Zell JA, Ou SH, Gandara DR, Anton-Culver H, Jablons DM (2007). "Natural history of stage I non-small cell lung cancer: implications for early detection". Chest. 132 (1): 193–9. doi:10.1378/chest.06-3096. PMID 17505036.
- ↑ Hyde L, Hyde CI (1974). "Clinical manifestations of lung cancer". Chest. 65 (3): 299–306. PMID 4813837.
- ↑ Herman M, Galanter M, Lifshutz H (1991). "Combined substance abuse and psychiatric disorders in homeless and domiciled patients". Am J Drug Alcohol Abuse. 17 (4): 415–22. PMID 1746503.
- ↑ Podbielski FJ, Rodriguez HE, Brown AM, Blecha MJ, Salazar MR, Connolly MM (2004). "Percutaneous biopsy in evaluation of lung nodules". JSLS. 8 (3): 213–6. PMC 3016799. PMID 15347106.