Lung mass imaging

Lung Mass Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Causes
Differentiating Lung Mass from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Diagnosis
Diagnostic Study of Choice
Evaluation of Lung Mass
Imaging of Lung Mass
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
X-ray
Echocardiography and Ultrasound
CT scan
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Lung mass imaging On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Lung mass imaging All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Lung mass imaging
CDC on Lung mass imaging
Lung mass imaging in the news
Blogs on Lung mass imaging
Directions to Hospitals Treating bone or soft tissue mass
Risk calculators and risk factors for Lung mass imaging

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2]

Overview

Computed tomography is the method of choice for the evaluation of lung mass. The evaluation of lung mass will depend on several characteristics, such as: calcification, margins, location, distribution, and attenuation. Further evaluation of lung mass, should include other diagnostic studies, such as: bronchoscopy, sputum cytology, or mediastinoscopy. Other imaging study useful for the malignancy evaluation of lung mass is PET scanning, which may be helpful for the detection of occult disease and malignancy assessment.

Imaging

Lung mass can be divided into 2 categories:

• Hyperdense pulmonary mass
• Cavitating pulmonary mass

Hyperdense pulmonary mass

• Hyperdense pulmonary mass is defined as a pulmonary mass with internal calcification
• The most common causes of hyerdense pulmonary mass, include: granuloma (most common), pulmonary hamartoma, bronchogenic carcinoma, carcinoid tumors, and pulmonary metastases.

Cavitating pulmonary mass

• Cavitating pulmonary mass is defined as a gas-filled area of the lung in the center of a nodule, mass or area of consolidation
• It is also characterized by a thick wall (must be greater than 2-5 mm)
• The most common causes of cavitating pulmonary mass, include malignancies, infections, inflammation processes, and congenital malformations.
• The table below summarizes the most common causes of cavitating pulmonary mass

Cavitating causes	Conditions	Description
Malignancy	Cancer Primary bronchogenic carcinoma(especially squamous cell carcinoma) Cavitating pulmonary metastases (especially squamous cell carcinoma, GI adenocarincoma, sarcoma)	Cancer Thick wall Irregular shape Disort of adjacent structures
Infection	Pulmonary bacterial abscess/cavitating pneumonia Empyema Post-pneumonic pneumatocoele Septic pulmonary emboli Pulmonary coccidioidomycosis Pulmonary actinomycosis / thoracic actinomycosis Pulmonary nocardiosis Melioidosis Pulmonary cryptococcosis	Abscess: Round in all projections Abruptly interrupts bronchovascular structures May form a acute angle with the costal surface / chest wall Abscesses have thick irregular walls Abscesses usually have an acute angle (claw sign) Empyema: Smoother margins Lentiform shape Distort and compresses adjacent lung Empyemas have obtuse angles
Non-infectious	Granulomatosis with polyangitis Rheumatoid nodules	May be single or multiple Size ranges from 0.5-7 cm 3,5
Vascular	Pulmonary infarct	Consolidation with internal air lucencies, "Bubbly consolidation"; this represent non-infarcted aerated lung parenchyma
Trauma	Pneumatocoeles	Smooth inner margins Contain little if any fluid Wall (if visible) is thin and regular Persist despite absence of symtpoms
Congenital	Congenital cystic adenomatoid malformation (CCAM) Pulmonary sequestration Bronchogenic cyst	Radiological features vary according to disease To learn more about congenital lung cavitations, click in the blue links.

Imaging Evaluation

• The evaluation of lung mass will depend on 5 characteristics: calcification patterns, size, location, margins, and attenuation.

Calcification

• Calcification patterns are commonly seen in granulomatous disease and hamartomas
• Calcification patterns are normally a sign of benignancy
• Characteristic benign calcification patterns of lung mass, include:

• Diffuse
• Central
• Laminated
• Popcorn

Size

• Any area of pulmonary opacification that measures more than 30 mm

Location

• Locations of lung mass, include:

• Pleural
• Endobronchial
• Parenchymal

Margins

• Different types of margins for lung mass, include:

• Lobulated or scalloped margins

• Intermediate malignancy probability

• Smooth margins

  Associated with benignancy

Attenuation

• Different types of attenuation for lung mass, include:
• Solid

• Malignancy rate of only 7%

• Calcified
• Partly solid

• Malignancy rate of 63%

• Ground glass

• Malignancy rate of 18%

Plain Radiograph

• On plain radiograph, characteristic findings of lung mass, include:

• Rounded or spiculated mass
• Bulky hilum (representing the tumor and local nodal involvement)
• Lobar collapse
• Cavitation may be seen as an air-fluid level
• Pleural effusion

CT

• Computed tomography is the method of choice for the evaluation of lung mass
• On CT scan, characteristic findings of lung mass, include:

• Single pulmonary nodule or mass
• Localized area of parenchymal consolidation
• Bubble-like areas of low attenuation within the mass are a characteristic finding
• Hilar and mediastinal lymphadenopathy is uncommon
• Persistent peripheral consolidation

MRI

• On MRI, there are no characteristic findings of lung mass
• MRI may be helpful for the assessment of mediastinal lymph nodes and diagnose distant metastasis (malignant lung masses)

Gallery

Plain Radiograph

• 

  Golden "S" Sign (or reverse "S" sign of Golden) : right upper lobar collapse (the right upper lobe appearing dense and shifting medially and upwards, with a central mass expanding the hilum

• 

  Squameous cell lung cancer: lung cavitating mass left upper lobe adjacent to the oblique fissure. The prominent air-fluid level is best seen on the lateral radiograph

• 

  Luftsichel sign: curvilinear opacity at the left apex represents compensatory hyperinflation of the left lower lobe

• 

  Coin lesion sign: round or oval, well-circumscribed lesion, compatible with primary lung cancer

CT

Malignant Lung Mass

• 

  Bronchogenic lung carcincoma: upper lobe collapse

• 

  Bronchogenic lung carcincoma: upper lobe with lymphangitic spread

• 

  Adenocarcinoma of the lung: ground-glass attenuation corresponds to a lepidic growth pattern and the solid component correspond to invasive patterns.

• 

  Squamous cell lung carcinoma: Peripheral squamous cell lung carcinoma may be seen as a solid nodule/mass with or without an irregular border. The irregular margin can be attributed to a desmoplastic reaction or infiltrative growth

Benign Lung Mass

• 

  Wegener granulomatosis

References

Template:WikiDoc Sources