Lung and Mediastinal Tumours Dr. Manu Mohan. K Asst. Professor Pulmonary Medicine
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