Lung Tumors PDF

 90 to 95% bronchogenic carcinoma  5% bronchial carcinoids  2-5% are mesenchymal   Etiology & Pathogenesis_Tobacco smoking ,Industrial hazards, air pollution,genetics& scarring. not all cigaratte smoking develop it so -- multifactorial   Squamous cell carcinoma_25- 40% ...

 90 to 95% bronchogenic carcinoma  5% bronchial carcinoids  2-5% are mesenchymal   Etiology & Pathogenesis_Tobacco smoking ,Industrial hazards, air pollution,genetics& scarring. not all cigaratte smoking develop it so -- multifactorial   Squamous cell carcinoma_25- 40%  Adenocarcinoma_25-40 %  Small cell carcinoma_20- 25%  Large cell carcinoma 10-15 % Histologic classification -- now days adenocarcinoma is overtaking squamous cell carcinoma -- squamous cell is strongly associated with cigaratte smokers while the adenocarcinoma is associated in non-smokers -- squamous cell carcinoma -- tumour differentiated towards the epithelium -- exhibit intercellular breach or karatin formation by the tumor cells -- further divided into well-differentiated, moderately-differentiated and poorly-differentiated. -- adenocarcinoma -- produces malignant glands -- small cell carcinoma -- arises from neuroendocrine cells -- don't show squamous differentiation nor glandular differentiation -- tumor cell grow in solid sheets composed of blue malignant tumor cells in the sheets -- large cell carcinoma -- also doesn't exhibit squamous cell differentiation -- tumor cells are large usually with prominent nucleoli In terms of clinical classificatio the bronchogenic are classified into :- -- small cell and non-small cell carcinoma -- because small cell is the only most agressive type of carcinoma -- surgery has no place -- poor prognosis squamous cell carcinoma -- produce karatin (pinkish material) -- variation in the nuclear staining in size and shape and chromotin distribution -- well differentiated squamous cell carcinoma -- pleomorphism is observed -- presence of prominent nucleoli -- presence of mitotic activity -- karatin formation adenocarcinoma :- -- tumor may arise from the lining epithelium of the bronchus, bronchiole, alveolar -- malignant glands variable in size and shape -- so formation of glands by the malignant tumor adenocarcinoma -- used to be called -- bronchioloalveolar carcinoma -- now days changed name -- because it doesn't invade the interstitium -- malignant epithelial cells are found along the alveolar septae without invasion into the stroma small cell carcinoma -- no squamous or glandular differentiation -- small round blue cells growing in solid fashion   Central (Brochogenic) carcinoma_75%  Peripheral lung carcinoma_25% classified according to the anatomical position -- centeral brochogenic carcinoma not visible in routen X-ray because it is hidden within the lung -- can't diagnose unless you do bronchoscopic examination where tissue diagnosis is possible -- peripheral -- diagnosed with chest X-ray in early stage of the disease --- cystoscopy is not possible   Local invasion  Lymphatic metastasis_hilar, scalene ,retrograde permeation of pleural lymphatics( pleural lymphatic carcinomatosis)  Blood stream metastasis_ adrenals(50%),liver (30%),brain (20%), bone (20%) & kidneys (15% ). -- along the mucousal surface -- may invade into the bronchial wall and eventually invade into the lung paranchyma -- direct invasion -- may spread by lymphatic route -- -- any organ can be evaded by this gross pathology -- gray white solid mass -- centerally located -- bronchogenic carcinoma -- almost obstructing the bronchous -- may result in brochio ectasis with obstruction -- or other forms of pneumoniea -- extension into the lung paranchyma observed -- carbon ladin lymph nodes are also involved small cell carcinoma -- tend to grow slowly and locally -- undergo cavitation -- carbon laden lymph nodes mass lesion infiltrating the bronchus and the lung paranchyma -- Peripharaly located bronchogenic carcinoma -- tumors visible in chest X-ray -- silent clinically -- unless they grow into the plueral space with pleural infusion  Earliest symptoms_ cough ,hemoptysis,dyspnea, chest pain & weight loss.  Bronchial obstruction_unresolving pneumonia,lung abscess &bronchiectasis.  Local invasion- effusion, superior vena caval obstruction ,dysphagia &_T_E fistula   Pan coast's syndrome –destruction of the T1 intercostal nerve- weakness & wasting of small muscles of the hand & numbness on the medial side of the arm.  Destruction of the cervical sympathetic trunk-Horner’s syndrome (ptosis of the eye lid, pupillary constriction & absent sweating on the side of the lesion). Pan coast's syndrome -- specific clinical manifestation of particularly apically located squamous cell carcinoma -- invade the thoracic nerve cell as well as the sympathetic trunk -- cause destruction of the intercostal nerve Horner's syndrome --   Distant Metastases-lymph node , bone fracture, brain masses.  Paraneoplastic syndromes, ectopic hormone production neuromuscular syndromes, skin rashes, migratory thrombophlebitis , dermatomyositis & polymyositis. earliest symptoms are non-specific symptoms -- the prognosis of the bronchogenic carcinoma by this time is really poor -- may be misdiagnosed as pulmonary tuberclosis -- fail to respond to treatment -- dysphagia involving the eosophagus   5 year survival rate 10 -20%  Stage 1 confined to the lung >3cm without node or small3cm with node, stage 3 includes all other lesions.  Non small cell carcinoma –tend to remain localized, surgical resection 30%  Bronchiolo –alveolar carcinoma _60% bronchiolo-alveolar carcinoma -- adenocarcinoma in-situ -- maybe diffuse and don't invade into the stroma hence they have an excellent prognosis   Multiple, single , peribronchial ,perivascular( lympangitis carcinomatosa, diffuse intralymphatic dissemination & tumor emboli in small vessels" pulmonary hypertension” metastasis is far more common than primary carcinoma -- alveolar capillaries act as filters for any tumor cells presenting in the pulmonary circulation -- lung is commonly involved by metastatic carcinomas -- either hematogenously or by lymphatic node -- the tumor may be deposited within the bronchial lumen and the metastasis located within the lymphatic space or small blood vessels. -- hematogenously metastesizing cancer to the lung -- most spread hematogenous routes or tend to peripheral location -- usually multiple and bilateral -- usually multiple and very rarely single diffuse metastasis -- tumor emboli are within small blood vessels -- resulting in pulmonary hypertension metastatic into the brain metastatic lung carcinoma -- multiple metastasis at the periphary -- -- plueral lymphatics are stranded by tumor emboli -- from breast cancer -- metastatic lung cancer -- hematogenous spread in the alveolar capillaries  Bronchial carcinoid. Bronchial carcinoid -- well differentiated neuroendocrine tumor -- intermediate differentiated neuroendocrine tumor also known as atypical bronchial carcinoid -- poorly differentiated nueroendocrine tumor -- small cell carcinoma -- younger age group -- tumor arises with in the bronchial lumen and then as the disease progresses may involve the whole and extend into the lung paranchyma -- detected at the early stage usually -- surgery is usually curative -- low-grade malignant tumors Atypical bronchial carcinoid -- more mitotic figuere -- exhibit necrosis -- more pleomorphism as compared to typical -- poor prognosis in comparision bronchial amartoma -- well defined margin -- cut section is hemogenous grey white solid -- clear demarcation between hemartoma and the normal lung paranchyma -- may be confuced with solitary bronchogenic carcinoma -- contain bronchial cartillage, bronchial epithelium, adipose tissue and other connective tissue Histology of amartoma -- benign lesion -- immature cartillage -- minor mucous glands also observed -- fibrous connective tissue   Solitary fibrous tumors  Malignant Mesothelioma Solitary fibrous tumors -- benign tumors arising from fibrous tissue which may result in benign neoplasm Malignant Mesothelioma -- very agressive malignant tumor arising from the pleura -- most often patients give history of asbestos exposure -- most specific neoplasm associated with exposure -- exhibit dual differentiation -- differentiate into epithelilial as well as mesenchymal -- malignant sprindle like or glandular structures -- very poor prognosis malignant mesetholoma -- lung paranchyma encased by this grey white mass -- extending into the lobular fissure -- malignant spindle cells -- fibrocarcoma (mesenchymal origin) -- also observe malignant glands -- dual differentiation into the epithelial and mesenchymal component is a feauture of malignnant mesetholoma