PATHOLOGYMost carcinomas fall into one of the following fourcategories Squamous cell carcinoma Adenocarcinoma Large cell carcinoma Small (oat) cell carcinoma Other rare tumours are clear cell, basal cell carcinosarcoma, etc.
CLINICAL PRESENTATIONWhen present as… Asymptomatic Recurrent pneumonia Cough, wheeze, hemoptysis Paraneoplastic syndromeslobectomy or pneumectomy may be curative
CLINICAL PRESENTATIONWhen presentation includes… Hoarseness Chest pain Brachial plexus neuropathy Horner’s syndrome SVC obstruction Dysphagia Features of cardiac tamponadeit indicates invasion of mediastinum or chest wall anda poorer prognosis.
IMAGING FEATURES (PERIPHERAL)Tumour shape and margins Generally are spherical or oval. Lobulation Corona radiata Tail between the mass and the pleura Usually have well defined edges, but some peripheral cancers like adenocarcinoma and bronchiolo-alveolar cell carcinoma have ill defined edges similar to pneumonia.
Bronchial carcinoma in the left lower lobeshowing typical rounded, slightly lobularconfiguration. The mass shows a notchposteriorly
CT demonstrating a second primary bronchogenic carcinomain the right lung in a patient who had undergone a previous leftpneumonectomy 7 years earlier. The new tumour hasspiculated edges infiltrating into the adjacent lung (coronaradiata).
Squamous cell carcinoma resemblingpneumonia. The entire opacity seen onthis radiograph is due to thecarcinoma itself
IMAGING FEATURES (PERIPHERAL)Cavitation Best demonstrated by CT Squamous cell carcinoma most likely to cavitate Cavity wall is usually 8 mm thick or greater Fluid levels are common.
EXAMPLES OF NEOPLASTIC CAVITATION ON CHESTRADIOGRAPHY.(A) The cavity is eccentric (large cell undifferentiated carcinoma).(B) The inner wall of the cavity is irregular and an air– fluid level is present (squamous cell carcinoma).(C) The cavity wall is very thin (squamous cell carcinoma).
CT showing cavitating squamous cell carcinoma.The wall of the cavity is variable in thickness.
IMAGING FEATURES (PERIPHERAL)Other findings Air bronchograms Bubble like lucencies or pseudocavitation Bronchocele, mucocele, mucoid impaction Ground glass attenuation of nodules or purely ground glass opacities.
Apical bronchiolo-alveolar cellcarcinoma of the left upper lobe withground-glass attenuation margins.
IMAGING FEATURES (CENTRAL) Cardinal imaging signs of a central tumour are collapse or consolidation of the lung beyond the tumour. Golden S sign Recurrent or persistent pneumonia and loss of volume of the lung without air bronchogram Drowned lobe Mucus filled dilated bronchi in the collapsed lobe on CT scan
(A) Collapse of a lobe around a central mass.(B) The middle lobe has undergone collapse, but there is a central mass causing the central portion of both the oblique and horizontal fissures to bulge outwards (arrows).
Fluid-filled dilatedbronchi beyond acentral obstructingcarcinoma are visiblein this collapsed andconsolidated leftlower lobe.
IMAGING FEATURES (BOTH)Hilar enlargement Common presenting feature Likely causes are the mass, lymphadenopathy consolidated lung or a combination of these More lobular the shape, the more likely that metastatic lymphadenopathy is present Increased density of the hilum owing to summation of the density of the hilum and the mass
Dense hilum. The right hilum is dense owing to a mass superimposed directly over it. The mass proved to be a squamous cell carcinoma.
RADIOGRAPHIC PATTERN OF EACH CELL TYPE Early and massive lymphadenopathy and direct mediastinal invasion are associated with small cell and large cell carcinomas A mass in and around hilum is characteristic of small cell carcinoma Peripheral nodule is very common on adenocarcinoma and large cell tumour Most adenocarcinomas and small cell tumours are small (<4 cm) Squamous cell carcinoma attain great size and cavitate more frequently Collapse and consolidation beyond the tumour is the most common feature seen with squamous cell carcinoma Pleural effusion (with dyspnoea) is a feature of adenocarcinoma
Massivemediastinaladenopathy in apatient withsmall (oat) cellcarcinoma ofthe bronchus.The primarycarcinoma isnot visiblebecause it liescentrally in thebronchial tree.
RADIOGRAPHIC PATTERN OF EACH CELL TYPE Bronchiolo-alveolar carcinomas present as peripheral pulmonary opacities Bubble like lucencies, air containing cystic lucencies, air bronchograms and cavitation may be seen It may also present as a patch of pneumonia in one or more lobes. Focal ground glass opacities
(A) Bronchiolo-alveolar carcinoma with widespread lung involvement. The appearance closely resembles bronchopneumonia or pulmonary oedema.(B) CT of a similar case showing the typical airspace filling with an obvious air bronchogram.
TREATMENT AND STAGING NSCLCStage Description Treatment OptionsStage I a/b Tumor of any size is found only in the Surgery lungStage II a/b Tumor has spread to lymph nodes Surgery associated with the lungStage III a Tumor has spread to the lymph nodes Chemotherapy followed in the tracheal area, including chest by radiation or surgery wall and diaphragmStage III b Tumor has spread to the lymph nodes Combination of on the opposite lung or in the neck chemotherapy and radiationStage IV Tumor has spread beyond the chest Chemotherapy and/or palliative (maintenance) care
SCLC Limited Stage Defined as tumor involvement of one lung, the mediastinum and ipsilateral and/or contralateral supraclavicular lymph nodes or disease that can be encompassed in a single radiotherapy port. Extensive Stage Defined as tumor that has spread beyond one lung, mediastinum, and supraclavicular lymph nodes. Common distant sites of metastases are the adrenals, bone, liver, bone marrow, and brain.
MEDIASTINAL INVASION Plain radiographic evidence relies on demonstrating phrenic nerve palsy Major CT AND MRI signs of mediastinal invasion relies on demonstration of the tumour deep within the mediastinal fat Glazer et al showed that A. Presence of less than 3 cm of contact with the mediastinum B. Less than 90 degrees of circumferential contact with the aorta C. A visible mediastinal fat plane between the tumour and any vital mediastinal organ indicates a very high probability of resectability and most of the patient with these descriptions had no mediastinal invasion on surgery.
(A) Extensive deep mediastinal invasion by primary bronchial carcinoma.(B) On lung windows there are pulmonary metastases
CHEST WALL INVASION Diagnosis of chest wall involvement unreliable on CT unless bone destruction or a large soft tissue mass is seen Local chest pain is the most specific indicator for involvement of parietal pleura or chest wall MRI is better than CT in demonstrating chest wall and diaphragmatic involvement MRI is the modality of choice for demonstrating Pancoast’s tumour Transthoracic ultrasound can diagnose chest wall invasion with a high degree of accuracy 99mTc radionuclide skeletal scintigraphy is sensitive to assess bone invasion
CHEST WALL INVASION BY A PANCOASTS TUMOUR.Involvement of the soft tissues of the chest wall isappreciated on the(A) coronal T1- and(B) T2-weighted MRI images.(C) This example from a different patient shows the better demonstration of bone involvement (arrows) on CT.
INTRATHORACIC LYMPH NODE METASTASES Lung cancer normally spread to ipsilateral hilar lymph nodes, then to the ipsilateral mediastinal lymph nodes, and then to the contralateral mediastinal and supraclavicular lymph nodes Skip metastases to mediastinal lymph node may occur Node with a short axis size of more than 10 mm is considered enlarged There is no measurement above which all nodes can be assumed to be malignant or below which all can be considered benign The predictive value of nodal metastatic disease may be improved by ensuring that the nodes draining the tumour are larger than the nodes elsewhere in the mediastinum STIR imaging produces sufficient difference between normal and pathological nodal tissue to detect metastases with 93% sensitivity and 87% specificity
INTRATHORACIC LYMPH NODE METASTASES Endoscopic ultrasound can be used to assess the size and morphology of, and to guide fine needle aspiration of aortopulmonary, subcarinal and posterior mediastinal nodes, achieving greater sensitivity and specificity than CT and PET in some series PET imaging has consistently demonstrated greater accuracy than CT and MRI in detecting nodal metastases, and accuracy increases on using PET- CT
There are severalenlarged nodes inthe rightparatracheal area.The largestmeasured 16 mmin its short axisdiameter (arrow).The primarytumour was abronchialcarcinoma in theright lung.
The largest of the rightparatracheal nodes(arrow) is 17 mm in itsshort axis diameter. Thisnode proved to be free ofmalignant tumour atthoracotomy. Theenlargement was due toreactive hyperplasia.None of the hilar ormediastinal nodes in thispatient was involved bytumour. The primarytumour can be seen in theright lung. It showsextensive contact with theright chest wall, but nodefinite evidence ofinvasion of the chest wallon CT. At surgery therewas invasion of the softtissues of the chest wallbut no spread to the ribs
Cavitatingbronchogeniccarcinoma. There ispreservation of theextrapleural fat planeat the point ofcontact with thechest wall. Althoughthe pleura may beinvolved the chestwall is likely to beotherwise spared.
RECURRENT MALIGNANT RIGHT HILAR LYMPHNODES FROM A SMALL PERIPHERAL NON-SMALLCELL LUNG CANCER.(A) CT demonstrates nodes at the right hilum.(B) The PET–CT image confirms high FDG uptake in keeping with malignant involvement.
PLEURAL INVOLVEMENT Occur d/t direct spread, lymphatic involvement or tumour emboli. Pleural effusion in association with a primary lung cancer designated the tumour as being T4 Some adenocarcinomas present as lobular pleural thickening indistinguishable from malignant mesothelioma.
PULMONARY SARCOMA AND OTHER PRIMARYMALIGNANT NEOPLASMS There are many other neoplasms that involve the lung like fibrosarcoma, leiomyosarcoma, carcinosarcoma, etc. but they all present as solitary pulmonary nodule or a tracheal or endobronchial mass Kaposi’s sarcoma is another important neoplasm caused due to the AIDS epidemic.
KAPOSI’S SARCOMA Rare in absence of cutaneous involvement Can involves both the parenchyma and the tracheobronchial tree May be focal or widespread (commoner) Perihilar linear, rounded or reticulonodular shadowing is seen Frequently associated with lymphadenopathy Pleural involvement in the form of b/l pleural effusion common feature
KAPOSIS SARCOMA IN TWO PATIENTS WITHAIDS.(A) Plain chest radiograph showing extensive pulmonary shadowing consisting of a mixture of ill-defined rounded and bandlike shadows maximal in the perihilar regions and lower zones.(B) CT showing the peribronchial distribution of the ill-defined pulmonary nodules. There is interlobular septal thickening, a feature that is also frequently identified on the chest radiograph.
TUMOURS OF THE TRACHEA Squamous cell carcinoma Adenoid cystic carcinoma (cylindroma) Mucoepidermoid carcinoma OthersPresent as either Mural nodule with lobular or irregular wall Stenotic lesion Paratracheal mass (adenoid cystic carcinoma)
Adenoid cysticcarcinoma of thetrachea. There isirregular polypoidtumour within thetracheal lumen.
BENIGN PULMONARY TUMOURSBronchial carcinoids Typical or central Atypical or peripheral They can invade locally and may metastasize Atypical carcinoids have a poorer prognosis Even small tumours can produce enough ACTH to cause Cushing’s syndrome Central masses show “iceberg” phenomenon Central tumours can cause bronchial obstruction and peripheral masses mimic bronchial carcinoma so removed surgically
CARCINOIDSA small tumour iscompletelyoccluding the rightmain bronchus andcausing extensivecollapse in the rightlung. Theendoluminalcomponent is wellseen (arrows), butthere is poordifferentiation of thetumour fromadjacent collapsedlung
A well-defined perihilar carcinoid tumour (arrows)is demonstrated anterior to the artery to the rightlower lobe. On lung windows there is only a smallband of atelectasis in the middle lobe
A small peripheralcarcinoid tumourindistinguishable froma number of othercauses of a solitarypulmonary nodule.
BENIGN PULMONARY TUMOURSPulmonary hamartoma Masses of cartilage with clefts lined by bronchial epithelium and contain large collection of fat Occasionally multiple Carney’s syndrome: triad of pulmonary chondroma, gastric epitheloid leiomyosarcoma and extra-adrenal paragangliomas 90% peripheral, 10% central Central tumours cause bronchial obstruction peripheral tumours on chest radiographs appear spherical or slightly lobulated, usually less than 4 cm, with normal surrounding lung with spotty, linear or popcorn calcification On CT it shows characteristic central fat density
Round, completely smooth, hamartoma in a 57 yearold asymptomatic man. There is typical coarsepopcorn calcification in this lesion which is unusuallylarge.
BENIGN LYMPHOPROLIFERATIVE DISORDERS Lymphocytic interstitial pneumonia Diffuse infiltration of pulmonary parenchyma by plasma cells and lymphocytes Commonly associated with underlying immunological disorders like Sjogren’s syndrome and AIDS Bilateral ground glass opacification and cysts Follicular bronchiolitis Hyperplasia of MALT in the airways Reticular or reticulonodular shadowing with centrilobular nodules and ground glass opacity, bronchial wall thickening, bronchial dilatation, interlobular septal thickening and peribronchovascular airspace consolidation is seen
MALIGNANT LYMPHOPROLIFERATIVE DISORDER Lymphoma Hodgkins lymphoma commoner than non-Hodgkin’s lymphoma May appear as one or more areas of pulmonary consolidation, s multiple pulmonary nodules or as miliary nodules and reticulonodular shadowing resembling lymphangitic carcinomatosa. The pulmonary opacities radiate outside from the hila Very rapid increase in the size of the lymphomatous deposits so that it gets confused with pneumonia has been seen in high grade non-Hodgkin’s lymphoma. Non- Hodgkin’s lymphoma of MALT type are most frequently encountered primary lymphomas of the lung and appear as solitary or multiple areas of consolidation with no lobar predilection and with prominent air bronchograms. A few of such lesions may show calcification but cavitation does not occur. Pleural effusions are common except in MALT type lymphoma
Primary pulmonary lymphoma. This appearancehad been very slowly progressive over severalyears.
MALIGNANT LYMPHOPROLIFERATIVE DISORDER Leukemia Pulmonary infiltration of lungs at autopsy is found in two- thirds of the patients with leukemia Usually asymptomatic Imaging features include diffuse bilateral reticulations and patterns resembling interstitial edema, lymphangitic carcinomatosis, small nodules, ground glass opacification or consolidation Mediastinal lymphadenopathy with pleural effusion may be present Pleural thickening due to a chloroma formation is also seen rarely Patients with leukostasis, which is seen when the WBC count is extremely high, present with dyspnea. Chest radiographs of such patients may be normal or show air space shadowing d/t pulmonary edema.
PULMONARY METASTASESArise usually from Breast GIT Kidneys Testes Head and neck tumours Bone and soft tissue sarcomas
PULMONARY METASTASESPresentation One or more discreet, spherical and well defined pulmonary nodules, but can be irregular (adenocarcinomas) and show cavitation (squamous cell carcinomas) Calcification unusual except in case of osteosarcoma and chondrosarcoma Rate of growth is variable (explosive in choriocarcinomas and osteosarcomas and extremely slow in thyroid carcinomas)
PULMONARY METASTASESTechniques for diagnosing metastases High kV films ( above 1 cm ) Sensitivity increased by CT, but specificity decreases especially in nodules below 6 mm When calcification can be identified, metastases can be excluded except for osteosarcoma and chondrosarcoma
PULMONARY METASTASESUse of CT to detect pulmonary metastases is forA. Investigation of a patient with normal chest radiograph in whom likelihood of metastases is high and in whom the demonstration of the presence of metastases would alter the managementB. Investigation of patients who are being considered for surgical resection of a known pulmonary metastases to look for further occult lesionsC. Distinction of solitary from multiple pulmonary nodules in a patient with an extrathoracic primary tumour in whom the diagnostic question is metastasis vs. primary bronchial carcinoma PET is useful for detecting of thoracic metastases, but weakness of PET is the limited sensitivity for nodules less than 10 mm.
Multiple, well-defined sphericalnodules in thelungs. Ribmetastases withassociated softtissue swelling arealso present(arrows). In thiscase the primarytumour was asynovial cellcarcinoma.
CT demonstrating a single peripheral metastasis(arrow). There were multiple lesions at other levels.The volume loss and scarring in the left lung issecondary to previous resection of the primarybronchogenic carcinoma.
Irregularpulmonarymetastases dueto metastaticadenocarcinomafrom anunknownprimary. Thenodules areirregular inoutline. A largeleft pleuraleffusion is alsopresent
LYMPHANGITIC CARCINOMATOSIS Permeation of pulmonary lymphatics and/or adjacent interstitial tissue by neoplastic cells Most common tumours that spread by this manner are Bronchus Breast Stomach Prostate May also develop secondary to blood borne emboli lodging in pulmonary arteries, direct extension from hilar lymph node, from pleura into adjacent interlobular septa or from a primary carcinoma of the lung into adjacent peribrochovascular interstitium
LYMPHANGITIC CARCINOMATOSIS Radiological features: Fine reticulonodular shadowing and/or thickened septal lines Subpleural edema visible as thickening of fissures Pleural effusion HRCT shows nonuniform, often nodular thickening of the interlobular septa and irregular thickening of the brochovascular bundles in the central positions of the lungs Nodular shadows may be seen scattered throughout the parenchyma
Unilaterallymphangiticcarcinomatosisdue to carcinomaof the bronchus,showing thickenedseptal lines andnodules confinedto the right lung
Bilaterallymphangiticcarcinomatosisshowing bilateralthickened septallines together withwidespreadnodulation of thelungs. The primarytumour in this 71year old woman waspresumed to be abronchial carcinoma(a diagnosis basedon sputumcytology).
High-resolution CT of lymphangitic carcinomatosis.Note the variable thickening of the interlobular septa and theenlargement of the bronchovascular bundle in the centre of thesecondary pulmonary lobules. The polygonal shape of the walls (septa) of the secondary pulmonarylobules is particularly well shown anteriorly. The pulmonary nodule is due to a discrete metastasis, a relativelyfrequent finding in this condition.
UNUSUAL PATTERNS OF METASTATIC CANCEREndobronchial metastasis: Airway obstruction is the dominant feature Melanoma Renal Colorectal BreastMiliary metastases: Thyroid Renal Bone sarcomas ChoricarcinomaTumour emboli: Pattern of pulmonary arterial hypertension Hepatoma Breast carcinoma Kidney Stomach Prostate Choriocarcinoma
SOLITARY PULMONARY NODULE Defined as a solitary circumscribed pulmonary opacity with no associated pulmonary, pleural or mediastinal abnormality measuring less than 3 cm in diameter Only 1% of solitary masses under the age of 35 will ne malignant
CAUSE OF SPN Bronchial carcinoma Carcinoid Granuloma Hamartoma Metastasis Chronic pneumonia or abscess Hydatid cyst Pulmonary hematoma Bronchocele Fungus ball Massive fibrosis in coal workers Bronchogenic cyst Sequestration Atriovenous malformation Pulmonary infarct Round atelectasis
SIMULANTS OF A SPN Extrathoracic artifacts Cutaneous masses Pleural tumours or plaques Encysted pleural fluid Pulmonary vessels
EVALUATION OF SPNRate of growth Benign lesions have a doubling time of either less than 1 month or greater than 18 months Malignant lesions have a doubling time between 1 and 18 months Exception in bronchiolo-alveolar cell carcinoma which may be very slow growing with larger doubling time A mass which has not grown over 2 yrs. is considered benign.
EVALUATION OF SPNAttenuation and enhancement A dense central nidus or diffuse calcification are good indicators of benignity If the calcification is in only a part of tumour or granular in nature then further evaluation is necessary by CECT A complete lack of enhancement (<15 HU) following CECT is indicative of benignity Nodules of ground glass attenuation are likely to be malignancy, most likely bronchiolo-alveolar cell carcinomaSize and margins are not very reliable indicators ofwhether the lesion is benign or malignant
Calcified infectiousgranuloma engulfedby lung cancer.CT shows a cluster ofdensely calcified smallnodules almost at thecentre of a smallcarcinoma.
Tumour calcification. Large bronchial carcinoma in leftlower lobe showing extensive amorphous and cloud-like calcification.Initial examination; no treatment had been given.
Contrast-enhanced CT for the evaluation of asolitary pulmonary nodule. There is differentialenhancement in this lesion that was due to aprimary adenocarcinoma
TO SUMMARIZE… When u see a SPN, first confirm its intrapulmonary location by taking a lateral radiograph or performing a CT scan Diffuse calcification, completely absent enhancement on contrast CT and no growth for 2 years signifies that the lesion is benign If it does not show any of the following characteristics then we assume it to of malignant etiology (it can be either an active granuloma or malignancy). Next step to be undertaken is a CT guided biopsy (core biopsy not FNAC)