Lung and Mediastinal Tumours

Dr. Manu Mohan. K

Asst. Professor

Pulmonary Medicine

Epidemiology

Most common form of malignant diseases 40,000 new patients per year 8% male deaths and 4% of all female

deaths Men > women, middle age

Etiological factors

Tobacco smoking

Cigarette smokers are 8-20 times more likely to develop lung cancer than life long non smokers.

Squamous and small cell carcinoma have clear association with smoking.

Adenocarcinoma is commonest histological type in a non smoker

Atmospheric pollution

Controversial

Radon - radiation

Occupational factors

Asbestos – mining, processing, usage. Radioactivity – metal ore mining, uranium

mining. Nickel – refining. Chromium salt – extraction, production,

usage. Arsenic – metal refining, chemical

industry, insecticides.

Pulmonary scarring

Localised areas of pulmonary scarring Diffuse pulmonary fibrosis Cryptogenic fibrosing alveolitis is

associated with adenocarcinoma Tuberculosis – scar carcinoma,

adenocarcinoma Bronchioloalveolar carcinoma also

occur in areas of scarring

Histological classification

1. Squamous cell carcinoma (epidermoid carcinoma)

2. Small cell carcinomaa. oat cell carcinomab. intermediate cell typec. combined oat cell

carcinoma

3. Adenocarcinoma a. acinar b. papillary adenocarcinomac. bronchioloalveolar d. solid carcinoma with mucous

4. Large cell carcinoma5. Adenosquamous carcinoma

6. Carcinoid tumours7. Bronchial gland carcinoma

a. adenoid cystic carcinomab. mucoepidermoid carcinomac. others

Growth factors

Polypeptides that take part in the control of cell differentiation and proliferation

Bombesin/gastrin releasing peptide – growth factor for small cell carcinoma

Non small cell carcinoma – few growth factors are recognized, EGF, TGF

Genetic abnormalities

Loss of short arm of chromosome in small cell carcinoma (p14, p23)

CDKN2 gene on chromosome 9 – Non small cell lung carcinoma

Oncogenes

myc genes – small cell lung carcinoma

Kras – adenocarcinoma

Tumour markers

Substances produced by tumour cells that are released in to blood stream.

Neuron specific enolase, creatinine phophokinase BB, CEA

Modes of presentation

Worsening of preexisting respiratory state.

No symptoms, detected by the chance of finding an opacity.

Nonspecific symptoms of malignancy like malaise, anorexia, and weight loss

Metastatic disease

Central tumours Cough – most common symptom New cough that persists longer than 2

weeks in a patient of 40 years who is a smoker.

Hemoptysis – usually streaky Breathlessness – due to central airway

narrowing, partial or total collapse of a distal segment

Chest pain – deep chest discomfort, due to peribronchial and perivascular nerve involvement.

Peripheral tumours

Cough and hemoptyis Bronchorrhoea Dyspnoea Chest pain

Distant spread

Skeletal metastasis – bone pain, pathological fractures

Cerebral metastasis – progressive neurological symptoms

Clinical features

Frequently no abnormal findings Hoarseness Bovine cough Clubbing HPOA

Lymphatic involvement – scalene and supraclavicular

Axillary lymph nodes due to chest invasion

Stridor, wheezes

Atelectasis Pleural effusion SVC obstruction Diaphragm palsy Enlarged liver Raised intracranial pressure Dysphagia

Investigations

Chest radiography Nearly always abnormal

Collapse Pleural effusion Elevated hemi diaphragm Widening of mediastinum Lymphangitis carcinomatosa Pneumonic shadow – bronchioloalveolar

carcinoma Pancoast tumour

Solitary pulmonary nodule (SPN)

Opacity of less than 3 cm without surrounding atelectasis and or adenopathy.

Doubling time Calcification

Solitary pulmonary nodule

Sputum cytology – more yield in central tumours

60-70% positive yield in experienced hands

Single sample – 40% 4 samples – 80%

Bronchoscopy – most useful for central tumours

Tumours beyond bronchoscopic view – Transbronchial needle biopsy, blind brushing and washing

Other investigations

Percutaneous needle biopsy Aspiration of subcutaneous swelling Pleural fluid study Thoracoscopic lung biopsy Mediastinoscopy Thoracotomy

StagingNon small cell carcinoma

TNM staging Primary tumour (T) Tx, T0, T1s, T1, T2, T3, T4 Nodal involvement (N) N0, N1, N2, N3. Distant metastasis (M) M0, M1

Staging

Small cell lung carcinoma Limited Extensive

Treatment

Non small cell lung carcinoma Surgery – best result, but only a

small minority Types of surgery Pneumonectomy Lobectomy VATS – segmentectomy 5 year survival rate overall 35%

Radiotherapy Stage I&II – inoperable due to medical

contraindicationsIndications Hemoptysis, pain, cough, dyspnoea due

to large bronchus obstruction, mediastinal compression, symptoms due to intracranial metastasis, symptoms due to spinal cord compression.

Endobronchial treatment

Laser therapy Endobronchial radiotherapy Photodynamic therapy

Chemotherapy

Poor response to chemotherapeutic agents

Combined modalities

Small cell carcinoma

At presentation 70% have extensive disease

Chemotherapy More sensitive to chemotherapy Combined therapy preferred than

monotherapy

Radiotherapy Primary tumour control Prophylatic cranial irradiation Surgery

Paraneoplastic syndrome

Non metastatic metabolic/neuromuscular manifestations

Hypercalcemia SIADH Ectopic ACTH HPOA

Gynaecomastia – large cell and adeno carcinoma

Eaton-Lambert syndrome, polymyositis/dermatomyositis

Peripheral neuropathy Cerebellar ataxia

Superior venacava obstruction

Small cell carcinoma Diagnosis – swelling of face and upper

torso and distension of veins across the chest, upper arms and neck.

Treatment – chemotherapy, radiotherapy and stenting

Superior sulcus tumour Pancoast Pain in lower part of shoulder and

inner aspect of the arm (C8, T1 and T2)

Sympathetic ganglion involvement – stellate

Diagnosis Treatment - radiotherapy and

surgery

Prevention

Primary prevention

Stop smoking

Mediastinum lies centrally within the chest and spans the region vertically from the thoracic inlet to the diaphragmatic hiatus, transversally between the parietal pleura, and coronally between the sternum and vertebral column.

Mediastinal Compartments

3 compartmentsAnterior compartment Middle compartment Posterior compartment

Anterosuperior compartment

Structures

Common lesions

Rare lesions

Ascending aorta

Thymomas Vascular lesions

Superior vena cava

Lymphomas Mesenchymal tumors

Azygos vein

Germ cell tumours

Endocrine tumours

Thymus glandLymph nodes

Transverse and great vesselsConnective tissue

Middle compartment

Structures

Common lesions

Rare lesions

Heart and Pericardium

Foregut cysts

Pleural and pericardial cysts

Trachea and bronchi

Lymphatic tumours

Neuroenteric and gastroenteric cysts

Posterior compartment

Structures Common lesions

Rare lesions

Sympathetic chain

Tumours of Neurogenic origin

Vascular tumour

Vagus nerves

Mesenchymal tumours

Thoracic duct

Lymphatic lesions

Lymph nodesDescending aorta

oesophagus

Symptoms and Mechanisms

Symptoms Mechanisms

cough Airway narrowing, compression

Chest pain Chest wall invasion, neural invasion

Dyspnoea Airway compromise, pericardial tamponade, pleural effusions, pulmonary stenosis, heart failure.

Hemoptysis Bronchogenic carcinoma, airway invasion, pulmonary stenosis, heart failure

Dysphagia Oesophageal narrowing/obstruction, oesophageal motor dysfunction

Hoarseness Vocal cord paralysis

Facial swelling Superior vena cava syndrome

Incidence

Adults65% in Anterosuperior, 10% in the middle and 25% in the posterior compartments

Children28% Anterosuperior, 10% in middle, 62% in the posterior compartment

Investigations

• Noninvasive diagnostic procedures• Computed tomography• Magnetic resonance imaging• Ultrasonography• Radio nuclides

Biochemical MarkersAFB, HCG – nonseminomatous germ cell tumour, Teratoma, Carcinoma

CEA Catecholamines,vanillylmandelic acid,

homovanillic acid – Pheochromocytoma Nor epinephrine, epinephrine –

paraganglioma,ganglioneuroma, neuroblatoma

Invasive biopsy proceduresFNABSurgical procedures

Lesions masquerading as mediastinal tumours

• Substernal Goiter• Cystic Hygroma• Lesions originating from thoracic

skeleton• Vascular lesions• Oesophageal lesions• Pulmonary lesions• Sub diaphragmatic Lesions

Paraneoplastic syndromes associated with Thymoma

Well established Myasthenia gravis Pure red cell aplasia Acquired hypogammaglobulinemia Non Thymic cancers

Less well established Pancytopenia Lambert-Eaton Peripheral neuropathies CNS changes Multiple endocrine defects Multiple rheumatologic disorders Nephrotic syndrome

Thymoma is the most common primary neoplasm of the mediastinum

15% of Thymic lesions Equal frequency in male and female 40-60 years 75% in anterior mediastinum More than 90% are visible on chest

radiograph

Surgical resection Radiotherapy Unresectable, recurrent or

metastatic Thymoma- chemotherapy

Tumours of lymph nodes

Lymphomas › 10-14% of mediastinal tumours› rare in posterior mediastinum› Hodgkin’s and Non Hodgkin’s› 20-30% asymptomatic› 60-70% symptoms of local

invasion› 30-35% systemic symptoms

Non-Hodgkin’s lymphoma› 5% with mediastinal involvement› Large irregular anterior and superior

mediastinal involvement› Radiation therapy effective in low grade

lymphoma› chemotherapy

Germ cell tumours

Benign and malignant

Benign germ cell tumours (Teratoma)

Constitute 70% of the lesions in children and 60% in adults.

Contain multiple tissues that are foreign to the part of the body in which they develop.

Symptomatic only when infected

Malignant germ cell tumours

Malignant mediastinal teratoma Mediastinal seminoma Nonseminomatous tumours-

embryonal carcinoma, choriocarcinoma, endodermal sinus tumours, teratocarcinoma

Chemotherapy and radiotherapy, surgery

Middle mediastinal tumours Bronchogenic cysts

Mediastinal cysts form 20% of mediastinal tumours

60% of mediastinal cysts are bronchogenic cyst

Oesophageal cysts Neuroenteric cysts Mesothelial cysts

Pericardial or pleuropericardial cysts

Thoracic duct cyst

• Neurogenic tumours• Most common malignancy in children• In children 50% malignant, adults 10%• Dumbbell tumours – intraspinal

extension• CT, MRI, myelography

Tumours of nerve sheath origin› Benign – neurilemoma or neurofibroma› Malignant tumours-incidence of

malignancy more in von Recklinghausen’s disease

› Poor prognosis

Posterior mediastinal tumours

Tumours of autonomic nervous system› Neuroblatoma, ganglioneuroblastoma

rare in adults

Endocrine tumours

Mediastinal pheochromocytoma

Parathyroid adenoma