Download Ppt On Bronchogenic Carcinoma ##VERIFIED##

Bronchogenic carcinoma is the leading cause of death from cancer in men and women in the United States. Although the cause of this malignancy is probably multifactorial, approximately 85% of lung cancer deaths are attributable to cigarette smoking. Patients may present with symptoms of airway obstruction caused by central tumors, symptoms related to direct tumor invasion of surrounding structures, or symptoms produced by distant metastases. There are four major cell types: adenocarcinoma, squamous cell carcinoma, undifferentiated large cell carcinoma, and small cell carcinoma. Adenocarcinoma and undifferentiated large cell carcinoma are generally peripheral lesions manifesting as solitary nodules or masses, whereas squamous cell carcinoma and small cell carcinoma are typically central and may manifest as hilar masses, atelectasis, or pneumonia. The prognosis for patients with bronchogenic carcinoma is poor, with an overall 5-year survival of 10%-15%. In general, patients with squamous cell carcinoma have the best prognosis, those with adenocarcinoma and undifferentiated large cell carcinoma have an intermediate prognosis, and those with small cell carcinoma have the worst prognosis.

Lung cancer or bronchogenic carcinoma refers to tumors originating in the lung parenchyma or within the bronchi. It is one of the leading causes of cancer-related deaths in the United States. Since 1987, lung cancer has been responsible for more deaths in women than breast cancer. It is estimated that there are 225,000 new cases of lung cancer in the United States annually, and approximately 160,000 die because of lung cancer. It is interesting to note that lung cancer was a relatively rare disease at the beginning of the 20th century. Its dramatic rise in later decades is attributable primarily to the increase in smoking among both males and females. This activity reviews the causes, pathophysiology, and presentation of lung cancer and highlights the role of the interprofessional team in its management.

Download Ppt On Bronchogenic Carcinoma

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Lung cancer or bronchogenic carcinoma refers to tumors originating in the lung parenchyma or within the bronchi. It is one of the leading causes of cancer-related deaths in the United States. Since 1987, lung cancer has been responsible for more deaths in women than breast cancer. It is estimated that there are 225,000 new cases of lung cancer in the United States annually, and approximately 160,000 people die because of lung cancer. It is interesting to note that lung cancer was a relatively rare disease at the beginning of the 20th century. Its dramatic rise in later decades is mostly attributable to the increase in smoking among both males and females.[1][2]

According to the WHO, identifying histologic features, measuring the depth of invasion, and mode of spread is of prognostic value. For example, they state that tumor spread through air spaces is associated with a higher recurrence rate after limited resections and should be reported on pathological evaluation. Also, the previously described clear cell, rhabdoid, and signet ring subtypes have been discontinued by the most recent WHO classification as they appear to be cytologic features that can occur in any adenocarcinomas. The WHO classification places significant emphasis on immunohistochemical staining to classify cancers that may not have typical cytologic features on light microscopy. In the 2015 WHO classification system, poorly differentiated carcinomas were reclassified as squamous cell carcinomas if they had p40 expression; as adenocarcinomas with solid subtype if they had thyroid transcription factor 1 expression; and neuroendocrine carcinomas if they had chromogranin and synaptophysin positivity.

These include atypical adenomatous hyperplasia (AAH) and adenocarcinoma in situ. AAH is a preinvasive lesion for lung adenocarcinoma and generally measures 5 mm or less. Adenocarcinoma in situ can be mucinous or nonmucinous and is generally a localized lesion of less than or equal to 3 cm. It shows a "lepidic" growth pattern defined as growth-restricted along the alveolar structures. It is noninvasive and shows intact alveolar septae.

Adenocarcinoma pathology consists of either neoplastic gland formation, pneumocyte marker expression (thyroid transcription factor 1 (TTF-1) with or without napsin expression, or intracytoplasmic mucin. It is further classified based on the extent and architecture of the neoplastic gland formation as mucinous or nonmucinous. Acinar, papillary, micropapillary, lepidic, and solid are nonmucinous subtypes. Pathological identification of these subtypes is important for prognosis. Solid, micropapillary, and cribriform (a subtype of acinar nonmucinous adenocarcinoma) patterns have adverse prognostic significance.[15] Although mucinous adenocarcinomas can have papillary, micropapillary, solid, and cribriform architecture, the WHO does not make any grading recommendations for mucinous carcinomas based on the growth patterns in a tumor. Other less frequent forms of adenocarcinoma include colloid, enteric-like, lymphoepithelial, and fetal.

Minimally invasive adenocarcinoma (MIA) is a small, solitary adenocarcinoma less than or equal to 3 cm with minimal invasion (less than 5 mm) and a predominant lepidic growth pattern, resembling other similar precursor glandular lesions. If the invasion is greater than 5 mm, it is defined as lepidic-predominant adenocarcinoma. Invasive mucinous adenocarcinoma, previously described as mucinous bronchioloalveolar carcinoma, comprises mucinous lesions that cannot be classified as MIA. If more than 10% of mucinous and nonmucinous growth patterns are present, the lesion should be classified as mixed adenocarcinoma.

Adenosquamous carcinomas are lung tumors with more than 10% glandular and squamous components. This is an uncommon and highly aggressive lung tumor, and current recommendations propose adjuvant chemotherapy even in Stage I radically resected tumors with whole-brain postoperative prophylactic radiotherapy due to the high risk of recurrence and brain metastasis with this subtype.[16]

Squamous cell pathology is defined by the presence of keratin and/or intercellular desmosomes on cytology or by immunohistochemistry (IHC) evidence of p40, p63, CK5, CK5/6, or desmoglein expression. Subtypes of squamous cell carcinoma include nonkeratinizing, keratinizing, and basaloid. Squamous cell carcinomas show extensive central necrosis with resulting cavitation. Squamous cell cancers can present as Pancoast tumors and hypercalcemia. A Pancoast tumor is a tumor in the superior sulcus of the lung. The brain is the most common site of recurrence postsurgery in cases of Pancoast tumors.

Large cell carcinoma (LCC) is a malignant epithelial neoplasm that does not have cytologic features consistent with glandular, squamous, or neuroendocrine cancers. They do not typically express p40 and TTF-1 on immunohistochemistry and lack cytologic features of small cell carcinoma. Typically LCC is comprised of round to polygonal cells with prominent nucleoli. The cells are large with abundant cytoplasm that does not have any defining features. LCC is a diagnosis of exclusion.[17]

Small cell carcinoma (SCLC) is composed of round, oval, or angulated cells, with a small amount of cytoplasm and size roughly that of a resting lymphocyte. No distinct nucleoli are seen. SCLCs are extensively necrotic. They usually stain positive with chromogranin or synaptophysin. The WHO previously classified SCLC into three cell subtypes: oat cell, intermediate cell, and combined cell (SCLC with NSCLC component, squamous, or adenocarcinoma). However, studies have shown that such classification does not have much clinical significance or prognostic value.[18]

Cough is present in 50 to 75% of patients with lung cancer.[2] Cough productive of large volumes of thin, mucoid secretions is seen in mucinous adenocarcinoma. In some cases, especially those with exophytic bronchial masses, a cough may signify secondary post-obstructive pneumonia. Hemoptysis is present in 15 to 30% of patients with lung cancer.[2] Chest pain is present in approximately 20 to 40% of patients with lung cancer, and dyspnea may be present in as many as 25 to 40% of the cases at the time of diagnosis.[2] These symptoms, however, may be primarily due to lung cancer or due to underlying bronchopulmonary disease.

Pleural involvement in lung cancer can manifest as pleural thickening/nodules or a malignant pleural effusion. During the course of their illness, approximately 10 to 15% of patients with lung cancer will have a malignant pleural effusion, with some showing a unilateral pleural effusion as the only presenting feature.[20] Bronchogenic carcinoma with associated ipsilateral malignant pleural effusion is considered unresectable; however, it must be noted that not all pleural effusions in patients with lung cancer are malignant.[21] A benign pleural effusion may occur due to lymphatic obstruction, post-obstructive pneumonitis, or atelectasis. If two consecutive cytology specimens are negative for malignancy in patients with bronchogenic carcinoma, surgical thoracoscopy or medical pleuroscopy is recommended to evaluate the pleural space before surgical resection of a primary lesion.[22] Medical pleuroscopy has a sensitivity of greater than 90% for detecting malignancy when present in patients with bronchogenic carcinomas.[23]

Neurologic paraneoplastic syndromes are immune-mediated syndromes associated with SCLC and include Lambert-Eaton myasthenic syndrome (LEMS), encephalomyelitis, limbic encephalitis, cerebellar ataxia, sensory neuropathy, and autonomic neuropathy.[30] Ectopic adrenal corticotropin production can cause Cushing syndrome and is associated with SCLC, large cell neuroendocrine carcinoma, and carcinoid tumors of the lung, and it portends a worse prognosis.[31] Other extrapulmonary clinical manifestations of lung cancers include hypertrophic pulmonary osteoarthropathy, dermatomyositis, and polymyositis. 006ab0faaa