Chapter 085. Neoplasms of the Lung (Part 18)

Bronchial Adenomas Bronchial adenomas (80% are central) are slow-growing endobronchial lesions; they represent 50% of all benign pulmonary neoplasms. About 80–90% are carcinoids, 10–15% are adenocystic tumors (or cylindromas), and 2–3% are mucoepidermoid tumors. Adenomas present in patients 15–60 years old (average age 45) as endobronchial lesions and are often symptomatic for several years. Patients may have a chronic cough, recurrent hemoptysis, or obstruction with atelectasis, lobar collapse, or pneumonitis and abscess formation.Bronchial adenomas of all types, because of their endobronchial and often central location, are usually visible by fiberoptic bronchoscopy. Because they are hypervascular, they can bleed profusely...
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Chapter 085. Neoplasms of the Lung (Part 18) Chapter 085. Neoplasms of the Lung (Part 18) Bronchial Adenomas Bronchial adenomas (80% are central) are slow-growing endobronchiallesions; they represent 50% of all benign pulmonary neoplasms. About 80–90%are carcinoids, 10–15% are adenocystic tumors (or cylindromas), and 2–3% aremucoepidermoid tumors. Adenomas present in patients 15–60 years old (averageage 45) as endobronchial lesions and are often symptomatic for several years.Patients may have a chronic cough, recurrent hemoptysis, or obstruction withatelectasis, lobar collapse, or pneumonitis and abscess formation. Bronchial adenomas of all types, because of their endobronchial and oftencentral location, are usually visible by fiberoptic bronchoscopy. Because they arehypervascular, they can bleed profusely after bronchoscopic biopsy, and thisproblem should be anticipated. Bronchial adenomas must be considered aspotentially malignant, thus requiring removal for symptom relief and because theycan be locally invasive or recurrent, potentially can metastasize, and may produceparaneoplastic syndromes. Surgical excision is the primary treatment for all typesof bronchial adenomas. The extent of surgery is determined at operation andshould be as conservative as possible. Often bronchotomy with local excision,sleeve resection, segmental resection, or lobectomy is sufficient. Five-yearsurvival rate after surgical resection is 95%, decreasing to 70% if regional nodesare involved. The treatment of metastatic pulmonary carcinoids is unclear becausethey can either be indolent or behave more like SCLC (Chap. 344). Assessment ofthe tempo and histology of the disease in the individual patient is necessary todetermine if and when chemotherapy or radiotherapy is indicated. Carcinoid and Other Neuroendocrine Lung Tumors Neuroendocrine lung tumors represent a spectrum of pathologic entities,including typical carcinoid, atypical carcinoid, and large cell neuroendocrinecancer, as well as SCLC. SCLC and large cell neuroendocrine cancer are high-grade neuroendocrine tumors and in general should be treated as described forSCLC. By contrast, typical carcinoid and atypical carcinoids are low- andintermediate-grade tumors with different treatment approaches and in general areresistant to chemotherapy (Chap. 44). Carcinoids, like SCLCs, may secrete otherhormones, such as ACTH or AVP, and can cause paraneoplastic syndromes thatresolve on resection. Uncommonly, bronchial carcinoid metastases (usually to theliver) may produce the carcinoid syndrome, with cutaneous flush,bronchoconstriction, diarrhea, and cardiac valvular lesions, which SCLC does notdo. Carcinoid tumors that have an unusually aggressive histologic appearance(referred to as atypical carcinoids) metastasize in 70% of cases to regional nodes,liver, or bone, compared with only a 5% rate of metastasis for carcinoids withtypical histology. Large cell neuroendocrine cancer is a high-grade NSCLC withneuroendocrine features. These tumors are characterized by histologic featuressimilar to small cell cancer, but they are formed by larger cells. The prognosis forpatients with large cell neuroendocrine cancer is significantly worse than that forpatients with atypical carcinoid and classic large cell cancer. Five-year survival is21% for patients with large cell neuroendocrine cancer, 65% for atypicalcarcinoid, and 90% for typical carcinoid. Thymomas See Chap. e12. Hamartomas Pulmonary hamartomas have a peak incidence at age 60 and are morefrequent in men than in women. Histologically, they contain normal pulmonarytissue components (smooth muscle and collagen) in a disorganized fashion. Theyare usually peripheral, clinically silent, and benign in their behavior. Unless theradiographic findings are pathognomonic for hamartoma, with popcorncalcification, the lesions usually have to be resected for diagnosis, particularly ifthe patient is a smoker. VATS may minimize the surgical complications. Metastatic Pulmonary Tumors The lung is a frequent site of metastases from primary cancers outside thelung. Usually such metastatic disease is incurable. However, two special situationsshould be borne in mind. The first is the development of an SPN or a mass onchest x-ray in a patient known to have an extrathoracic neoplasm. This nodule mayrepresent a metastasis or a new primary lung cancer. Because the natural history oflung cancer is often worse than that of other primary tumors, a single pulmonarynodule in a patient with a known extrathoracic tumor is approached as though thenodule is a primary lung cancer, particularly if the patient is >35 years and asmoker. If a vigorous search for othe ...