lung tumor radiology

Imaging of Lung

Tumors

Roshan Valentine

Outline • Introduction

• Carcinoma bronchus - pathology, symptoms - radiological features - diagnostic imaging - staging - assessing treatment

• Rare primary malignant neoplasms• Benign pulmonary

tumors• Intrathoracic lymphoma

and leukemia• Metastatic lung disease• Evaluation of solitary

pulmonary nodule

Introduction

• A wide variety of neoplasms arise in the lungs

• Many are overtly malignant, others are definitely benign

• Some fall in between these two extremes

Introduction• Lung cancer is the most common cause of cancer death in

developed countries.

• The prognosis is poor, with less than 15% of patients surviving

5 years after diagnosis. The poor prognosis is attributable to lack of

efficient diagnostic methods for early detection and lack of

successful treatment for metastatic disease.

Introduction

• The usefulness of the various imaging examinations largely depends on the clinical findings at the time of presentation and also on the stage of the disease

• Many imaging modalities are used to further evaluate the findings seen on the previous imaging and to determine the stage of the disease.

Bronchial carcinoma• Most common cause of cancer in men

• 6th most frequent cancer in women

• Leading cause of cancer mortality worldwide – 20%

• In India, approximately 63,000 new lung cancer cases are reported each year.

• Major risk factor is cigarette smoking which is implicated in 90% of cases.

• Other risk factors include radon, asbestos, uranium, arsenic, chromium

Pathology

• NSCLC(80%)• Squamous(35%)

• Smoking , cavitate , poor prognosis• Adeno (30%)

• Women , non-smokers, peripheral• Large cell (15%)

• SCLC (20%)• Smoking, metastasises early, paraneoplastic syndromes and SVC

obstruction• Worst prognosis

Clinical features

• Cough, wheeze, sputum production, breathlessness, chest discomfort, hemoptysis

• Asymptomatic(20%)

• Finger clubbing, SVC obstruction, Horner’s syndrome, chest wall pain, dysphagia, pericardial tamponade

• Abnormal CXR in asymptomatic patients

• Paraneoplastic syndromes

Radiological features

• Reflect pathology

• Depend on size, site, histology

Radiological features

1. Hilar enlargement

2. Airway obstruction

3. Peripheral mass

4. Mediastinal involvement

5. Pleural involvement

6. Bone involvement

Hilar enlargement

• Enlargement or increased density- 1 central tumor

• Peripheral tumors - Bronchopulmonary lymph nodes

• Extensive hilar and mediastinal lymphadenopathy - small

cell tumors

Hilar enlargement

Airway obstruction

• Collapse – segmental / lobar / entire lung• Consolidation – infection distal to obstruction prior to

collapse – absent air bronchogram

• Mucocele or bronchocele due to mucoid impaction

Airway obstruction

Central mass

• Shape of the collapsed or consolidated lobe may be altered

because of the bulk of the underlying tumor

• Fissure in the region of the mass is unable to move in the

usual manner , and fissure may show a bulge – Golden S sign

Airway obstruction

Airway obstruction Bronchocele

Peripheral mass

• Common presentation of lung Ca• Larger; poorly defined, lobulated, umbilicated or spiculated

margins (Corona radiata)• Satellite opacities – more in benign than malignant • Calcification – diffuse or central • Doubling time – 1-18 months ; >2 yrs – benign

Peripheral mass• Cavitation – central necrosis or abscess formation

• Malignant cavities – thick walled, irregular nodular

inner margin

• Pancoast/ superior sulcus tumors – lung apex – tendency to invade

ribs, spine, brachial plexus, and inferior cervical sympathetic

ganglia

Peripheral mass

Pancoast tumor

Mediastinal involvement

• Lymph nodes : SCLC, mediastinal widening, lobulated outline

• Esophagus : compression or invasion - barium swallow

• Phrenic nerve : elevated hemidiaphragm, paradoxical movement on fluoroscopy

• SVC : obstruction on dynamically enhanced CT/MRI

• Pericardial invasion : pericarditis or pericardial effusion

Mediastinal involvement

Pleural involvement

• Pleural effusion : direct spread, lymphatic obstruction,

obstructive pneumonitis, sympathetic response

• Spontaneous pneumothorax : cavitating subpleural tumor

Bone involvement

• Direct invasion : peripheral carcinomas-ribs / spine

• Hematogenous : lytic, identified earliest by isotope bone scan

• Hypertrophic osteoarthropathy – well defined periosteal new

bone formation

Diagnostic imaging

• The prognosis and treatment of lung cancer depends

on the general condition of the patient and on the histology

of the tumor and its extent at the time of presentation

Diagnostic imaging

• SCLC – metastasise early, disseminated at presentation, chemosensitive

• NSCLC – metastasise later, esp. squamous

• Central tumors – sputum cytology, bronchoscopic biopsies or washings

• Peripheral tumors – percutaneous biopsy with fluoroscopic,

CT or USG guidance

Diagnostic imaging

Staging

Purposes

• Identify patients with NSCLC who will benefit from surgery

• To avoid surgery in those who will not benefit

• To provide accurate data for assessing and

comparing different methods of treatment

Staging

Nodal stagIng

Alveolar cell carcinoma

• Bronchiolar or bronchio-alveolar Ca

• Subtype of adeno Ca

• Peripherally, probably from type II pneumocytes

• Not associated with smoking

• May be associated with diffuse pulmonary fibrosis and pulmonary scars


Two patterns:

• Focal form – solitary peripheral mass, air bronchograms often visible, may spread via airways to progress to diffuse pattern

• Diffuse form – multiple acinar shadows, with areas of confluence

CT : ground glass opacification, small nodular opacities, frank consolidation, thickened interlobular septa

Rare primary malignant neoplasms

Pulmonary Kaposi’s sarcoma • AIDS• Segmental or lobar consolidation• Multiple nodular and linear opacities• Pleural effusions• Hilar and mediastinal lymphadenopathy


Pulmonary artery angiosarcoma• Hilar mass• Signs of pulmonary embolism and pulmonary artery

hypertension


• Fibrosarcoma• Leiomyosarcoma• Carcinosarcoma• Pulmonary blastoma • Malignant hemangiopericytoma

Often present as solitary pulmonary mass radiologically indistinguishable from a carcinoma of the lung

Benign pulmonary tumors

• Bronchial carcinoid

• Pulmonary hamartoma• Bronchial chondroma

• Pulmonary fibroma

• Pulmonary myxoma

• Plasma cell granuloma

• Bronchial papilloma

Bronchial carcinoid

• Neuroendocrine tumors derived from APUD cells

• Typical(90%) and atypical

• 80% arise in lobar or segmental bronchi

• Cause bronchial obstruction, collapse, recurrent segmental pneumonia, bronchiectasis, abscess formation.

• Peripheral carcinoids –well circumscribed round or ovoid solitary nodules

Bronchial carcinoid

Pulmonary hamartoma

• Consists of abnormal arrangement of tissues normally found in

the organ concerned

• Large cartilaginous component, and appreciable fatty component

• Solitary nodule in an asymptomatic adult

• Rare in childhood

Pulmonary hamartoma

• Peripheral

• Well circumscribed nodules

• Do not cavitate

• Low density within denotes fat

• 30% show calcification on x-ray with popcorn appearance

• Grow slowly on serial films

Pulmonary hamartoma

Intrathoracic lymphoma and leukemia

Hodgkin’s disease • MC lymphoma

• Usually arises in lymph nodes – hilar or mediastinal node enlargement on CXR

• Lymphadenopathy – frequently bilateral, asymmetrical, involves anterior

mediastinal glands

• CT – Paraspinal and retrosternal nodes

Hodgkin’s disease • Involves lung parenchyma in 30%

• Pulmonary infiltrate may appear as solitary areas of consolidation,

larger confluent areas or miliary nodules

• Pulmonary opacities may have an air bronchogram and may cavitate

• Pleural effusion due to lymphatic obstruction, pleural plaques may

be seen

Hodgkin’s disease

Non – Hodgkin’s disease

• Radiologic manifestations are similar to Hodgkin’s disease

• Progression of disease is less orderly

• Pulmonary and pleural involvement precedes mediastinal disease

Non – Hodgkin’s disease

Pseudolymphoma

• Tumor like condition which behaves benignly

• Focal

• Solitary or multiple areas of pulmonary consolidation

• Air bronchogram, cavitation may occur

Lymphomatoid granulomatosis

• Angiocentric, angiodestructive lymphoreticular, proliferative and

granulomatous disease predominantly involving the lungs

• A T-cell non-Hodgkin’s lymphoma

• Multiple ill defined nodules resembling metastases

Lymphomatoid granulomatosis

Leukemia

• Radiographic abnormalitites are due to the complications of the disease

• Mediastinal lymph node enlargement, pleural effusion, pulmonary

infiltrates

• More common in lymphatic than myeloid leukemia

Metastatic lung disease

• Hematogenous > lymphatic > Endobronchial

• Primaries – breast, skeleton, urogenital system, colon, melanoma

• Bilateral ,basal predominance, often peripheral and subpleural

• Spherical, well defined margins


• Cavitation – Squamous carcinomas and sarcomas

• Calcification – Osteosarcoma, chondrosarcoma, mucinous

adenocarcinoma

• Endobronchial metastases – Ca kidney, breast, colon


Lymphangitis carcinomatosa

• Hematogenous metastases occluding peripheral pulmonary lymphatics

• Lung, breast, stomach, pancreas, cervix and prostate

• CXR - Coarse, linear, reticular and nodular basal shadowing, pleural effusions and hilar lymphadenopathy

• HRCT – Nodular thickening of interlobular septa, thickening of centrilobular bronchovascular bundles

Metastatic lung disease Lymphangitis carcinomatosa

Solitary pulmonary nodule

• Defined as a solitary circumscribed pulmonary opacity 3 cm in diameter with no associated pulmonary, pleural or mediastinal abnormality

• 40% of SPNs are malignant


Causes• Bronchial carcinoma• Bronchial carcinoid• Granuloma• Hamartoma• Metastases• Chronic pneumonia or

abscess• Hydatid cyst• Pulmonary hematoma

• Bronchocele• Fungus ball• Massive fibrosis in coal workers• Bronchogenic cyst• Sequestration• AVM• Pulmonary infarct• Round atelectasis


Mimics

• Extrathoracic artefacts

• Cutaneous masses

• Bony lesions

• Pleural tumors or plaques

• Encysted pleural fluid

• Pulmonary vessels


Factors to differentiate• Size• Calcification• Enhancement• Growth rates• Shape• Margin

SIZE• >3cm : Malignant unless proved otherwise

Calcification

Enhancement on ct• Post contrast : > 20HU s/o malignancy

GrowthW.r.t Doubling time of the lesion• Malignant : 1-6months• Benign : > 18months

Shape• Polygonal shape • Three-dimensional ratio > 1.78 - sign of benignity

A

B

margin

• Corona radiata sign - highly associated with malignancy • Lobulated or scalloped margins - intermediate

probability• Smooth margins - more likely benign

Air Bronchogram sign

• A/w malignancy

• Bronchoalveolar ca and adenocarcinoma

lung tumor radiology

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