|Year : 2018 | Volume
| Issue : 2 | Page : 53-60
Clinical, Radiological, and Histopathological Profile of Patients with Endobronchial Lesions on Fiber-Optic Bronchoscopy
Sandeep Rana1, Brig Debajyoti Bhattacharyya2, CDS Katoch3, Kislay Kishore4, Anand Arora5
1 Graded Specialist, Department of Respiratory Medicine, Military Hospital, Dehradun, India
2 Medicine and Respiratory Medicine, Department of Respiratory and Sleep Medicine, Army Hospital Research and Referral, Pune, Inida
3 Department of Respiratory, Critical Care and Sleep Medicine, Military Hospital Cardiothoracic Centre, Pune, India
4 Graded Specialist, Respiratory Medicine, Command Hospital Central Command, Lucknow, India
5 Classified Specialist, Department of Pathology, Military Hospital, Jammu, India
|Date of Web Publication||10-Jul-2018|
Department of Respiratory Medicine, MH Dehradun, PIN-248003
Source of Support: None, Conflict of Interest: None
Background: Fiberoptic bronchoscopy is very important tool for evaluating the profile of endobronchial lesion. Endobronchial profile provides important clue regarding likely pathology which is of immense help for clinician and pathologist to reach definitive diagnosis. Aim and Objectives: To study the clinical, radiological, and histopathological profile of endobronchial lesions detected during bronchoscopy. Materials and Methods: A cross-sectional prospective observational study was conducted at a tertiary respiratory center. Demographic, clinical, and radiological profile was prepared for all patients above 18 years of age, and relevant blood and radiological investigations were conducted. Patients detected to have endobronchial lesion during fiberoptic bronchoscopy were selected for the study. Bronchoalveolar lavage, bronchial biopsy, and bronchial brushing were done and sent for examination. Patients were observed postprocedure for any complication. Results: Male patients were more in number (70%) with most of patients above 40 years of age (80%). Most common symptom was cough (48%) with smoking history present in 48% patients. Mass lesion was most common radiological presentation (52%). Right lung was most commonly involved (52%), and upper lobe involvement was most common (50%). Exophytic growth was most common endobronchial lesion (46%) with carcinoma lung most common diagnosis (74%). Hemoptysis was most common complication (80%), which resolved on its own, followed by postprocedure hypoxemia (8%). Conclusion: Clinical, radiological, and bronchoscopic profile of endobronchial lesion is an important information which helps clinician and pathologist to reach final diagnosis. Carcinoma lung is most common diagnosis made in our study as most common endobronchial lesions at age of our patients are malignant as reported in literature.
Keywords: Endobronchial lesions, fiberoptic bronchoscopy, pathological profile
|How to cite this article:|
Rana S, Bhattacharyya BD, Katoch C, Kishore K, Arora A. Clinical, Radiological, and Histopathological Profile of Patients with Endobronchial Lesions on Fiber-Optic Bronchoscopy. J Assoc Chest Physicians 2018;6:53-60
|How to cite this URL:|
Rana S, Bhattacharyya BD, Katoch C, Kishore K, Arora A. Clinical, Radiological, and Histopathological Profile of Patients with Endobronchial Lesions on Fiber-Optic Bronchoscopy. J Assoc Chest Physicians [serial online] 2018 [cited 2018 Jul 18];6:53-60. Available from: http://www.jacpjournal.org/text.asp?2018/6/2/53/236273
| Introduction|| |
Ikeda designed a flexible fiberoptic bronchoscope (FOB) in 1968 and used for various pulmonary conditions for diagnosis. FOB has now become a very important tool in diagnosis and treatment of endobronchial lesions. Endobronchial lesion is any lesion, benign or malignant, arising from bronchial wall. Pulmonologists come across significant number of endobronchial mass lesions on bronchoscopy. Clinical and radiological features of these lesions may not differentiate between different etiologies, and sampling is required to distinguish benign from malignant lesions. However, limited information is available from India on the spectrum of diseases causing endobronchial lesions and its epidemiology. Fiberoptic bronchoscopy informs us about types and number of lesions, involvement of bronchial segments, and may help in staging and mode of therapy for carcinoma. The present study was undertaken to study clinical, radiological, and histopathological profile of endobronchial lesions detected during bronchoscopy.
| Materials and Methods|| |
All patients scheduled for fiberoptic bronchoscopy were evaluated with case history and detailed clinical examination. Following investigations were carried out: hemoglobin, prothrombin time, international normalized ratio, sputum for AFB (acid fast bacillus), and HIV (human immunodeficiency virus) test. Patient were explained the procedure of FOB. Patients were nebulized before bronchoscopy with 2.5-mg solution of salbutamol and 3-ml 4% lignocaine. FOB was done with Pentax Bronchofiberscope (FB 19 TV). All patients detected to have endobronchial lesions were included in the study.
All patients above 18 years of age undergoing fiberoptic bronchoscopy and detected to have endobronchial lesion at a tertiary care respiratory center.
- Lack of patient’s consent for the study.
- HIV-positive cases.
- Deranged coagulation profile.
- Compromised cardiovascular status.
- A cross-sectional prospective observational study to determine the clinical profile of endobronchial lesions and their pathological correlation.
- The sample size was 50 patients.
- Institutional and ethical clearance was obtained before conduction of the study.
- Patients detected to have endobronchial lesion undergoing fiberoptic bronchoscopy.
Patients underwent bronchoalveolar lavage (BAL), bronchial biopsy, and bronchial brushing. BAL were sent for Ziehl Neelsen stain and Mycobacterium tuberculosis culture sensitivity in Lowenstein Jensen medium, Gram’s stain, pyogenic culture, fungal stain, and malignant cells. Bronchial brushing was sent for cytology. Five bronchial samples were taken, and one sample was sent for M.ycobacterium tuberculosis culture sensitivity in normal saline, and four samples were sent for histopathological examination in formalin.
Postprocedure patient were observed for complications like hypoxemia and hemoptysis for 2 h.
| Results|| |
Patients included in study were 50 in number. All smokers were active smoker with two (4%) exposed to both biomass fuel and smoking. All of patients were either bidi or cigarette smoker with no hookah or other methods of smoking. Thirteen (26%) patients also had associated comorbidities.
Most common complaint was cough in 24 (48%), followed by breathlessness on exertion in 22 (44%), chest pain in 17 (34%), loss of appetite and weight loss in 13 (26%), hemoptysis in four (8%), fever in two (4%), hoarseness of voice in two (4%), and tightness of muscles was found in two (4%).
Examination of patient was done and absent or decreased breath sound was the most common finding in clinical examination, detected in 29 (42%) of patients followed by adventitious breath sounds in 10 (20%), lymphadenopathy in four (8%), clubbing in two (4%), pallor in two (4%), and engorged neck vein in one (2%) of cases.
All cases had radiological features suggestive of lung disease in chest X-ray or in contrast enhanced computed tomography (CECT) chest. Most common finding was mass lesion which was detected in 26 (52%) patients, and collapse consolidation was equally found in 13 (26%) patients. Other findings were pleural effusion in 10 (20%) patients, mediastinal lymphadenopathy and reticular nodular opacities in seven (14%) cases, and cavitory lesions were detected in two (4%) cases.
Fiberoptic bronchoscopy was done in 50 cases for diagnostic purpose, and endobronchial lesion was detected and described as exophytic, nodular, ulcerative, or plaque. Right lung was involved in 26 (52%) cases, left lung in 23 (46%) cases, and both lungs were involved one (2%) case.
Most common lobe involved was upper lobe which was involved in 25 (50%) of cases followed by right or left main bronchus in 19 (38%) of cases, and middle/lingular lobe and lower lobe were equally involved in three (6%) of cases.
Most common endobronchial lesion detected in FOB was exophytic in 23 (46%) of cases; out of them, 17 (34%) had fungating growth and six (12%) had globular lesions. Nodular lesions were detected in 14 (28%) cases, and ulcerative/plaque lesions were detected in 13 (26%) cases [Graph 1]
During fiberoptic bronchoscopy, 42 (84%) lesions bleeded on touch, and eight (16%) did not have any episode of bleeding on touch. Most common complication observed in postprocedure period was hemoptysis which was observed in 40 (80%) cases. Hypoxemia was observed in six (12%) cases, and four (8%) did not have any major complication.
Endobronchial lesion biopsy, brush biopsy, bronchial wash specimen were sent for histopathological examination. Most common diagnosis was carcinoma of lung, which was detected in 37 (74%) cases. Only four cases were detected to have suspicion of malignancy in bronchial wash, and one was found to be positive for AFB bacilli and one had mycobacterium tuberculosis (MTB) culture positive. All cases were confirmed on histopathological report. Chronic inflammation without any evidence of infection or malignant changes was detected in five (10%) cases. Normal histomorphology was confirmed in three (6%) cases. Endobronchial tuberculosis was confirmed in two (4%) cases. Other diagnosis confirmed on histological examinations were sarcoidosis in one (2%), bronchial polyp in one (2%), and benign mesenchymal neoplasm in one (2%) cases [Graph 1].
Carcinoma lung—demographic and histopathological profile
Most common histopathological variant diagnosed was squamous cell carcinoma which was detected in 18 (36%) of cases [Figure 1]. Adenocarcinoma [Figure 2] followed with 10 (20%) cases diagnosed histopathologically. Nonsmall-cell carcinoma was detected in four (8%) of all cases. Others variants were small-cell carcinoma of lung (SCLC) in two (4%), carcinoids, mucoepedermoid carcinoma, and adenoid cystic variant of salivary gland tumor in one (2%) case each [Graph 1].
Carcinoma lung was more common diagnosis in males with 27 (54%) cases, and 10 (20%) females were diagnosed with carcinoma lung. Most common variant in males was squamous cell carcinoma with 14 (28%) cases followed by adenocarcinoma in nine (18%) cases, nonsmall-cell carcinoma in two (4%) and mucoepidermoid and carcinoid representing one (2%) case each. Most common variant of carcinoma lung detected in females was squamous cell lung carcinoma too with four (8%) cases followed by adenocarcinoma lung, non-SCLC, SCLC with two (4%) cases each, and adenoid cystic carcinoma (salivary gland tumor) [Figure 3] representing one (2%) case.
Carcinoma lung and relation with smoking
In this study, 46% cases of lung carcinoma were associated with smoking, 6% cases were associated with biomass fuel smoke, and two (4%) were associated with tobacco chewing. No association of tobacco consumption was found in 44% of cases detected to have carcinoma lung.
All cases of small-cell carcinoma, though two in number, were associated with tobacco, one each with smoking and biomass fuel. Squamous cell lung carcinoma (11 out of 18 cases) was associated with tobacco consumption in 61% of cases, out of which eight were associated with smoking, two with tobacco chewing, and one with biomass fuel smoke. Adenocarcinoma (four out of 10 cases) was associated with tobacco consumption in 40% of cases, and all were associated with smoking. Non-SCLC (two out of four cases) was associated in 50% of cases and association with smoking and biomass fuel smoke in each case. Mucoepidermoid variant and carcinoid tumor, though less in number, was not associated with history of smoking.
| Discussion|| |
Endobronchial lesions are frequently encountered during FOB. Clinical profile of individual including name, age, sex, smoking history, symptoms, radiological picture, and profile of endobronchial lesions including type (nodular, exophytic, plaque, or ulcerative), location, friability of lesion tells about the likely possibility of diagnosis. But diagnosis is generally confirmed by histopathological examination. In this study, diagnostic yield with FOB was 98% with one case of carcinoma lung needed trucut biopsy for confirmation of diagnosis.
In this study, male preponderance in a ratio of 7:3 for diagnostic bronchoscopy was likely due to heterogeneous population of armed forces and also because of the fact that risk factors associated with respiratory diseases like smoking, tobacco chewing are more common in males. Most of patients (80%) were of older than 40 years of age with people older than 60 years (42%) constituted largest group. This is likely because of the fact that most common diagnosis made after bronchoscopy was carcinoma lung and most of cases underwent FOB were suspected of malignancy and chances of carcinoma lung increases with age.
Smoking was a risk factor in 48% of cases who underwent FOB and 52% were nonsmokers. Smoking is associated with greater than 90% of carcinoma lung cases and also common risk factors for various lung diseases like airway diseases causing symptoms like cough, breathlessness, and dyspnea, which are the most common indications for FOB., Most common symptom of patient was cough which is similar to previous published studies. Chest pain and breathlessness on exertion were also common complaints of patients. Hemoptysis was a primary complaint in only four patients.
Most common clinical finding was decreased or absent breath sounds due to malignant pleural effusion or endobronchial lesion/external compression, causing collapse of lung which was confirmed later. Clubbing was detected in only four patients, out which one patient was a known case of idiopathic pulmonary fibrosis.
Most common radiological finding was mass lesion detected in CECT chest or chest X-ray followed by consolidation and collapse. Other findings were pleural effusion reticular nodular opacities, mediastinal lymphadenopathy, and cavitory lesions. Similar findings are published in various case studies.
Right lung was involved in 52% of cases and upper lobe was involved in 50% of cases. Similar reports have appeared in literature.,,, Left lung was involved in 46% of cases, and bilateral lesions were present in 2% of cases. Right and left main bronchus was involved in 38% of cases followed by 6% each in middle/lingular and lower lobes. Most common finding detected during FOB was exophytic growth, which was detected in 46% of patients. Similar reports are available in literature., In this study, most common diagnosis was carcinoma lung, and this explains the similarity of lesions detected in our study and lesions reported in other studies published in literature.
Most common complication confronted after FOB was hemoptysis, which was observed in 80% of individual who underwent bronchoscopy. Hemoptysis can be explained by the invasive nature of procedure (endobronchial biopsy), friability of lesion, and surrounding unhealthy mucosa. Hypoxemia was observed in 12% cases which can be explained by compromised cardiopulmonary system due to nature of disease, associated obstructive airway diseases, and old age. No major complications like laryngospasm, bronchospasm, severe hemoptysis, severe dyspnea were observed, and no mortality was observed. Hemoptysis subsided on its own, and hypoxemia was treated with oxygen supplementation. FOB has been considered a very safe procedure and mortality figures varies from 0.01% to 0.5% and major complications varies from 0.08% to 5% in published literature.,
Carcinoma lung was the most common diagnosis made which was histopathologically proved in 37 (74%) of cases. Most common histological type was squamous cell carcinoma of lung, which was confirmed in 18 cases out of 37 followed by adenocarcinoma which was confirmed in 10 cases. Preponderance of squamous cell carcinoma can be attributed to the fact that squamous cell lung carcinoma is central in location and thus more amenable to FOB. Smoking may also have contributed to increase in squamous cell carcinoma as smoking is more commonly associated with this histopathological variant, and perhaps this is still the most common variant in Asia. Chronic inflammation was detected in 10% of cases. Most of the cases were subjected to FOB to rule out malignant lesions, due to their clinical and radiological profile, which explains the majority of diagnosis. Other diagnosis like endobronchial sarcoidosis, benign mesenchymal lesion, tuberculosis, and bronchial polyp are not so common entities detected routinely in FOB and that can explain small proportion contributed by these diseases in our study.
A study published in 2013 by Sharma and Bansal reported almost equal cases of adenocarcinoma and squamous cell carcinoma in bidi smokers. This difference may be attributed to the fact that diagnosis of malignancy was confirmed by different methods like pleural fluid cytology, computed tomography (CT)-guided fine needle aspiration (FNAC), and FOB in the study, and thus, peripheral lesion were also diagnosed which are not visible by FOB. Peripheral lesions are more common in adenocarcinoma of lung. Gupta et al. have also published study in 2010 in which squamous cell lung was detected as most common histopathological variant.
Around 60% (11 out of 18) of squamous cell carcinomas were associated with smoking, and out of them, two were associated with tobacco chewing (smokeless tobacco). Association of carcinoma lung with smokeless tobacco was confirmed in experimental models.,, Another factor for these reports may be attributed to appearance of oral cancer earlier then lung cancer in tobacco chewer, which is more commonly associated with chewing tobacco.
Nonsmall-cell carcinoma was diagnosed in four cases, small-cell carcinoma in two cases and one each case of mucoepidermoid, adenocystic carcinoma, and lung carcinoid was diagnosed. Similar proportion of non-SCLC and SCLC were detected in literature. SCLC constitutes 15% of total cases of carcinoma lung. More than 90% cases of SCLC are associated with smoking, and risk rises with increase in duration and intensity of smoking. In our study, two cases were diagnosed as SCLC and both of the cases were smokers.
Paraneoplastic syndrome was associated with one case that had superior vena cava syndrome manifested by engorgement of veins of upper thorax and neck veins which is the most common paraneoplastic manifestation in SCLC patients. Other common manifestation is syndrome of inappropriate secretion of antidiuretic hormone, which is associated with 15% to 40% of cases. Other manifestations like Lambert Eaton syndrome, encephalomyelitis are associated with only 2% to 3% of cases.
Carcinoid is a very rare tumor representing only 0.5% to 2.5% of pulmonary neoplasm. In our study, patient was symptomatic with hemoptysis for 3 months, which is explained by the vascular nature of lesion. Patient was nonsmoker and in literature no evidence has been found of relationship between tobacco and carcinoids. Patient may present with atelectasis, recurrent pneumonia due to obstruction, but in our case, lesion was present in left main bronchus and not completely occluding the bronchus. Patient had no evidence of carcinoid syndrome which can be a presenting feature in <5% of cases, evident by presence of flushing, wheezing, anxiety, vomiting due to production of 5-hydroxytryptamine, bradykinin, prostaglandines, etc.
Salivary gland tumors are rare tumors of lung which have four variants mucoepidermoid, adenocystic, acinic cell, and oncocytoma. In our study, we had two cases confirmed as a case of salivary gland tumors. Adenocystic carcinoma was detected in female of middle age with history of cough and breathlessness. FOB revealed fleshy, globular lesion in left main bronchus, completely occluding the bronchus and giving rise to symptoms. Mucoepidermoid carcinoma was detected in young male presenting with cough and chest pain in right side. Endobronchially, he had exophytic lesion in right upper lobe bronchus with cheesy white material exuding after endobronchial biopsy.
In our study, we have diagnosed two cases as a case of endobronchial tuberculosis. One case was young adult with radiological evidence of consolidation right lower lobe with no evidence of tuberculosis on sputum examination. He was detected to have a nodular lesion at right carina 1 which had positive growth for M. tuberculosis. Another case was an old man with suspicion of carcinoma lung. He was detected with cauliflower growth and bronchoalveolar lavage revealed positive stain for M. tuberculosis. Endobronchial biopsy from cauliflower growth confirmed the diagnosis of non-SCLC. A study published by Cicenas et al. in World Journal of Surgical Oncology revealed 2.1% of cases diagnosed with pulmonary tuberculosis in 2218 patients who underwent surgery for carcinoma lung. Scar formation after tuberculosis may cause carcinoma formation as per one theory, and another theory suggests deformation of lymphatic and blood vessels by scar causing lymph stasis and thus hampering the clearance of carcinogens from scarred area.,
Endobronchial sarcoidosis was diagnosed in a patient with primary complaints of tightness of muscles and enlarged inguinal lymph nodes. Patient had nodular lesions in bronchovascular area with consolidation in posterior segment of left lower lobe. FOB revealed multiple nodular lesions in left main bronchus. Histopathological examination revealed nonnecrotizing compact granuloma, suggestive of sarcoidosis. Endobronchial sarcoidosis is present in 40% of stage 1 and approximately in 70% cases in stage 2, three cases. Endobronchial biopsy has very good yield for sarcoidosis even in normal appearing mucosa and yield increases with any abnormality detected like unhealthy mucosa, nodular lesions, and some had described mass like lesion.
Benign mesenchymal neoplasms are rare benign tumors detected in FOB. In our study, one middle-aged woman who presented with progressive breathlessness on exertion and chest pain on right side was detected with benign mesenchymal neoplasm. Radiologically, patient had collapse of right lung with shifting of mediastinum to right side. Benign mesenchymal neoplasms are a group of endobronchial lesion that may include lipoma, chondroma, leiomyoma, fibroma, and hamartoma. Hamartomas are most common benign lesions of lung which are predominantly intraparenchymal in location. Endobronchial lesion presents with endobronchial symptoms like cough, hemoptysis, and complications like obstructive collapse and recurrent pneumonia. Normal histomorphology was detected in 6% of cases, and nonspecific inflammation was reported in 10% of cases. Similar reports have appeared in previous studies.
Bronchial polyps are rare benign lesions detected during FOB. In our study, we had one case of bronchial polyp. Patient was young, who presented with 5-year history of blood in sputum and recurrent bouts of cough. Endobronchial examination revealed fleshy lesion in bronchus intermedius. Inflammatory polyps are rare lesions which are detected in generally middle-age individuals. Patients generally present with cough, hemoptysis, and breathlessness on exertion.
In this study, one case of carcinoma lung was also having Ascaris species worm in bronchial segment of right lower lobe. Patient presented with history of dry cough for 2 months. Clinical findings were suggestive of pleural effusion right side. CT imaging of chest revealed mass lesion right lower lobe. Patient was subjected to FOB which revealed worm-like structure coming out from segmental bronchus of right lower lobe. Endobronchial biopsy revealed chronic inflammation initially. Patient was treated for Ascariasis and reviewed after 1 month. Patient had deteriorated in 1 month, and he was subjected again to FOB. This time patient had unhealthy mucosa in right lower lobe with worm-like structure still present in segmental bronchus. Endobronchial biopsy revealed Ascaris species and adenocarcinoma of lung. This was the first and only instance when FOB has to be repeated for making a diagnosis. A retrospective analysis done in post Graduate institute (PGI) Chandigarh on repeated FOB by Balamugesh et al. has revealed the overall incidence for repeat FOB was 6.34%. Most common indication was finding the pathology, and most common diagnosis after repeat FOB was bronchogenic carcinoma.
| Conclusion|| |
Clinical and radiological profile in combination with endobronchial profile provides various clues to clinician as well as pathologist to reach the diagnosis, and this study reinstates worth of fiberoptic bronchoscopy in confirming the diagnosis of endobronchial lesions. This study also reinstates the safety of fiberoptic bronchoscopy as complication rates were very low and no mortality reported. It is recommended to publish such data to enrich the knowledge of clinician and pathologist to foresight and reach the diagnosis early.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Ikeda S. Flexible-bronchofiberscope. Ann Otorhinolaryngol 1970;79:916-23.
Alberg AJ, Samet JM. Epidemiology of lung cancer. Chest 2003; 123(1 Suppl):21S-49S.
U.S. Department of Health and Human Services. The health consequences of smoking: A report of the surgeon general. CDC publication no. 7829. Washington, DC: Public Health Service, Centers for Disease Control and Prevention 2004.
Prakash UBS, Offord KP, Stubbs SE. Bronchoscopy in North America: The ACCP survey. Chest 1991;100:1668-75.
Pavlovska I, Danilovski D, Orovchanec N. An epidemiologic study of some characteristics of lung cancer. Folia Med 2004;46:23-31.
Atıcı AG, Erkan L, Fındık S, Uzon O, Kandemir B. Clinical features of non-small cell lung cancer cases. Tüberk Toraks 2004;52:150-8.
Sevgi E, Akkurt İ, Özşahin SL, Ardic S, Altinors M, Daycan B et al.
A retrospective analysis of 189 patients wıth lung cancer. Turk J Med Sci;17:191-9.
Alamoudi OS. Lung cancer at a University Hospital in Saudi Arabia: A four-year prospective study of clinical, pathological, radiological, bronchoscopic, and biochemical parameters. Ann Thorac Med 2010;5:30-6.
] [Full text]
Devkota KC, Pathak R, Khanaland A, Chokhani R. Fiber-optic bronchoscopy: Seven-year experience at Nepal Medical College Teaching Hospital. Nepal Med Coll J 2010;12:260-3.
Sahin F, Yıldız P. Radiological, bronchoscopic and histopathologic characteristics of patients with primary lung cancer in Turkey (2006–2009). Asian Pac J Cancer Prev;12:1947-52.
Credle WF, Smiddy JF, Elliott RC. Complications of fiberoptic bronchoscopy. Am Rev Respir Dis 1974;109:67-72.
Dreisin RB, Albert RK, Talley PA, Kryger MH, Scoggin CH, Zwillich CW. Flexible fiberoptic bronchoscopy in the teaching hospital. Chest 1978;74:144-9.
Sharma PK, Bansal R. Profile of lung cancer in predominantly bidi smoking rural population of Northern Himachal Pradesh. Indian J Chest Dis Allied Sci 2013;55:75-8.
Gupta S, Bhalotra B, Jain N. Spectrum of intrabronchial mass lesions and role of flexible bronchoscopy in their diagnosis: A series of 74 cases. Indian J Chest Dis Allied Sci 2010;52:79-82.
International Agency of Research on Cancer. Tobacco habits other than smoking; betel quid and areca nut chewing; and some related nitrosamines. 1985. p. 1-268.
Rivenson A, Jecht SS, Hoffman D. Carcinogenicity of tobacco specific N
-nitrosamines (TSNA): The role of vascular network in the selection of target organs. Crit Rev Toxicol 1991;21:255-64.
Bhurgri Y, Decullier E, Bhurgri A, Nassar S, Usman A, Brennan P et al.
A case-control study of lung cancer in Karachi, Pakistan. Int J Cancer 2002;98:952-5.
Devesa SS, Bray F, Vizcaino AP, Parkin DM. International lung cancer trends by histologic type: Male:female differences diminishing and adenocarcinoma rising. Int J Cancer 2005;117:294-9.
Meerbeek JP, Fennel DA, Ruysscher DKMD. Small lung cancer. Lancet 2011;378:1741-55.
Hurt R, Bates M. Carcinoid tumour of the bronchus: A 33 year experience. Thorax 1984;39:617-21.
Fink G, Krelbaum T, Yellin A, Bendayan D, Saute M, Glazer M et al.
Pulmonary carcinoids: Presentation, diagnosis, and outcome in 142 cases in Israel and review of 640 cases from literature. Chest 2001;119:1647-51.
Gustafsson BI, Kidd M, Chan A, Malfertheiner MV, Modlin IM. Bronchopulmonary neuroendocrine tumors. Cancer 2008;113:5-21.
Moran CA, Suster S, Askin FB, Koss MN. Benign and malignant salivary gland-type mixed tumors of lung. Cancer 1994;73:2481-90.
Cicenas S, Vencevicious V. Lung cancer in patients of tuberculosis. World J Oncol 2007;5:1-5.
Matsumura T, Watanabe K. Management of mycobacteriosis in general hospital without isolation ward for tuberculosis patients. Clinical study on pulmonary tuberculosis associated with lung cancer patients. Kekkaku 1999;75:157-62.
Zhingel IP, Tsimmerinov IE. Diagnosis of cancer of lung in patients with tuberculosis subjects with post-tuberculosis changes of lung. Probl Tuberculoza 1999;6:26-9.
Lynch JP III, Kazerooni EA, Gay SE. Pulmonary sarcoidosis. Clin Chest Med 1997;18:755-85.
Hurts R. Benign tumors of bronchus and trachea, 1951–1981. Ann R Coll Surg Engl 1984;66:22-6.
Dixit R, George J, Rai SML. Endobronchial inflammatory polyp. JIACM 2010;11:312-5.
Balamugesh T, Aggarwal AN, Gupta D, Behera D, Jindal SK. Profile of repeat fiberoptic bronchoscopy. Indian J Chest Dis Allied Sci 2005;47:181-5.
[Figure 1], [Figure 2], [Figure 3]