The Journal of Association of Chest Physicians

ORIGINAL ARTICLE
Year
: 2017  |  Volume : 5  |  Issue : 2  |  Page : 76--80

Chest X-ray of lung cancer: Association with pathological subtypes


Arnab Saha1, Kaushik Saha2, Santanu Ghosh2, Mrinmoy Mitra3, Prabodh Panchadhyayee4, Aditya P Sarkar5,  
1 Sanjiban Multispecialty Hospital, Howrah, West Bengal, India
2 Department of Pulmonary Medicine, Burdwan Medical College & Hospital, Burdwan, West Bengal, India
3 Department of Pulmonary Medicine, Calcutta National Medical College & Hospital, Kolkata, West Bengal, India
4 Department of Pulmonary Medicine, Midnapore Medical College & Hospital, Paschim Medinipur, West Bengal, India
5 Department of Community Medicine, Bankura Sammilani Medical College & Hospital, Bankura, West Bengal, India

Correspondence Address:
Kaushik Saha
Rabindra Pally, 1st Lane, Nimta, Kolkata - 700 049, West Bengal
India

Abstract

Background: Chest radiography is an essential initial investigation for the suspected cases of bronchogenic carcinoma and can be a predictor of malignancy. Aims: To assess the radiographic presentation and distribution of the different pathological cell types of lung cancer in our hospital. Materials and Methods: A total of 125 consecutive suspected patients with lung cancer, who had initial chest X-ray lesions suspicious of malignancy (mass lesion, nodules, pleural effusion, evidence of bronchial obstruction such as collapse, unresolved consolidation, etc.), were selected as the study population. The contrast-enhanced computed tomography (CT) scan of the thorax, CT-guided fine-needle aspiration cytology, fiberoptic bronchoscopy and Tru-cut biopsy were performed in the patients as feasible to find out the pathological cell type of bronchogenic carcinoma. Then, the chest X-rays were clinically correlated in all the lung cancer cases. In addition, the relationship of chest X-ray with the pathological cell types was assessed in the cases of lung cancer. The data were presented and analysed by the standard statistical method. Results: In our study, squamous cell carcinoma was the predominant cell type (47.12%) followed by adenocarcinoma (29.81%). Squamous cell carcinoma and small cell carcinoma commonly presented as central lesions, whereas adenocarcinoma and large cell carcinoma manifested most frequently as peripheral lesions. The common radiographic presentation of squamous cell carcinoma was collapse (38.78%) followed by unresolved consolidations (28.57%) and masses, whereas adenocarcinoma mostly presented as nodules (38.71%) followed by pleural effusion (29.03%). Small cell carcinoma, large cell carcinoma and undifferentiated carcinoma mostly manifested as mass lesion on chest radiography. Conclusion: Chest roentgenography can provide a clue about the pathological cell types of bronchogenic carcinoma, especially in the cases of hilar or parahilar lesions, collapse, non-resolving consolidations and effusions.



How to cite this article:
Saha A, Saha K, Ghosh S, Mitra M, Panchadhyayee P, Sarkar AP. Chest X-ray of lung cancer: Association with pathological subtypes.J Assoc Chest Physicians 2017;5:76-80


How to cite this URL:
Saha A, Saha K, Ghosh S, Mitra M, Panchadhyayee P, Sarkar AP. Chest X-ray of lung cancer: Association with pathological subtypes. J Assoc Chest Physicians [serial online] 2017 [cited 2019 Sep 15 ];5:76-80
Available from: http://www.jacpjournal.org/text.asp?2017/5/2/76/206130


Full Text

 Introduction



Bronchogenic carcinoma is the most common malignancy of men in the world and the leading cause of death in males suffering from cancer in 35 different countries.[1] It is the sixth leading malignancy in women worldwide.[2] Tobacco smoking is the most vital contributing factor in the development of lung cancer, with approximately 80–90% of deaths directly caused by tobacco use.[3],[4],[5] The common histological cell types, which comprise over 95% of all primary lung cancers, are adenocarcinoma, squamous cell carcinoma, undifferentiated large cell carcinoma and small cell carcinoma.[6] Various imaging techniques such as plain chest roentgenography, computed tomography (CT) scan and magnetic resonance imaging provide crucial help in the diagnosis of lung cancer. An initial chest X-ray guide clinicians to do the required investigation for diagnosis of bronchogenic carcinoma. We can also predict the pathological type of lung cancer by observing the chest X-ray.[7],[8]

The aim of our study was to determine the significant differences in radiographic abnormalities in respect to the pathological cell types of lung cancer with correlation between chest radiographic presentation and the pathological cell type of lung cancer.

 Materials and Methods



This observational, cross-sectional study was conducted at the Department of Pulmonary Medicine, Burdwan Medical College and Hospital, Burdwan, West Bengal. A total of consecutive 178 clinically and radiologically suspected patients with lung cancer were screened, and 125 patients were selected for the study on the basis of inclusion and exclusion criteria.

Inclusion criteria:Patients above 18 years of age and both sexes.Patients with initial chest X-ray lesions suspicious of malignancy (mass lesion, evidence of bronchial obstruction such as collapse, non-resolving consolidation, nodules, etc.).

Exclusion criteria:Sputum that was Acid fast bacilli (AFB) positive.Diagnosed or suspected pneumonia.Respiratory failure.Without written consent.

The diagnosis of lung cancer and the pathological cell type was determined by either CT-guided fine-needle aspiration cytology (FNAC) or biopsy and/or flexible fiberoptic bronchoscopy (FOB). FOB was used primarily to diagnose the central lung lesions, whereas CT-guided FNAC or biopsy was performed mainly to diagnose the peripheral lesions. After the workup, a total of 21 patients were excluded from the study due to the benign nature of the disease. The chest X-rays of 104 patients with the diagnosis of primary lung cancer were analysed, and the relationship with the pathological cell types was assessed. Radiographs were coded, and no information regarding the clinical details or the cell type of lung cancer was available at the time of interpretation. Radiographs were evaluated based on number, location, distribution and other characteristics of the lesions including the details of calcification, cavitation, satellite lesions and involvement of adjacent structures if any. Each radiograph was submitted to one of the two participating radiologists who did not have the knowledge of the cell type. Specific radiographic findings on the chest X-ray film were evaluated and recorded on a standard form. The radiograph was then re-read by the second radiologist, and discrepancies were settled prior to analysing data.

Data management and statistical analysis

Data management was performed by using the Statistical Package for the Social Sciences version 12 software (SPSS Inc., Chicago, IL, United States). Descriptive statistics (means, standard deviations and frequencies) were performed to describe the study variables. Fisher’s exact test and chi-square test were performed to evaluate the relationship between chest X-ray pattern and the pathological of significance was set at P value <0.05 throughout the analysis.

 Result and Analysis



Among 125 cases, 104 cases were malignant, and 21 cases were non-malignant. The malignant cases included 81 (77.88%) males and 23 (22.12%) females [Table 1]. Squamous cell carcinoma was the most predominant pattern (49 or 47.11%) of lung malignancies followed by adenocarcinoma, small cell carcinoma, poorly differentiated carcinoma and lastly large cell carcinoma [Figure 1]. The most common non-malignant lesions were granulomatous lesion (52.38%) followed by chronic inflammatory lesion (28.57%).{Table 1}{Figure 1}

Most of the lung cancers (73.08%) presented on the right side of the hemithorax. The involvement of squamous cell carcinoma was mostly in the upper zone (53%) followed by the mid zone (28.57%). In case of adenocarcinoma, the lower zone (51.61%) followed by the mid zone (25.81%) was the most common involvement. In small cell and large cell carcinomas, the mid zone followed by the upper zone was the frequent involvement. Most of the cases of poorly differentiated carcinoma did not follow the proper zonal distribution [Table 1].

The common radiographic manifestations were collapse, mass, nodules, consolidations, pleural effusion and wide mediastinum. Squamous cell carcinoma most commonly presented as collapse (38.78%) followed by consolidations (28.57%), whereas the presentation of adenocarcinoma was mostly nodules (38.71%) followed by pleural effusion (29.03%). Small cell carcinoma, large cell carcinoma and poorly differentiated carcinoma mostly manifested as mass lesion in chest radiography (P value <0.0001) [Table 2]. The distribution of radiographic lesions among the different pathological subtypes of lung cancer was statistically significant (P value<0.0001) as analysed by chi-square test.{Table 2}

Squamous cell carcinoma and small cell carcinoma commonly presented as central lesions, whereas adenocarcinoma and large cell carcinoma manifested most frequently as peripheral lesions [Figure 2]. The radiographic location of the different pathological subtypes of lung cancer was statistically significant (P value <0.001) as analysed by Fischer’s exact test.{Figure 2}

Cavitation was observed in nine cases, and all were squamous cell carcinomas. Calcification was seen in a single case of small cell carcinoma. In nine cases, we found satellite lesion, of which six were adenocarcinomas, two were poorly differentiated carcinomas and one was small cell carcinoma. Diaphragmatic palsy and rib involvement were most commonly observed in squamous cell carcinoma. Pericardial effusion was only seen in adenocarcinoma [Table 2].

 Discussion



The diagnosis of lung cancer depends on the detection of malignant cells in the sputum for three consecutive days, cytopathology specimens obtained by CT-guided FNAC or biopsy specimens obtained by FOB or Tru-cut biopsy, and initially and more importantly, on specific abnormalities observed on chest radiographs.

The most common radiographic findings of bronchogenic carcinoma were pulmonary masses, hilar enlargements and multiple pulmonary nodules.[8] The significant radiographic findings in our study were collapse, consolidations, masses, nodules, wide mediastinum and pleural effusions with parenchymal lesions (masses or nodules). In a study conducted by Bazot et al.,[9] parenchymal masses were 66.6%, hilar lymphadenopathy were 60% and peripheral nodules were 73%. Maula et al.[10] showed that the predominant radiologic presentations were hilar masses and collapse. Our study showed findings that were similar to the study by Maula et al.[10] Our significant radiological presentations were collapse, masses and consolidation followed by peripheral nodules.

In our study, the right hemithorax (73.08%) was the most common site of involvement of lung cancer. Bilateral involvement was found only in one case of squamous cell carcinoma.

Sharma et al.[11] showed that squamous cell carcinoma occurred most commonly in the upper zone followed by the mid zone, which was similar to our study’s findings. They showed that adenocarcinoma was not maintaining any zonal distribution pattern. However, according to our study, the most common site of involvement was the lower zone followed by the mid zone in the cases of adenocarcinoma of the lung. Sharma et al. also showed that small cell carcinoma frequently occurred in the mid zone followed by the lower zone. Our experience was slightly different. We showed that the most common site of involvement of small cell carcinoma and large cell carcinoma was the mid zone followed by the upper zone. We could not draw any conclusion about the specific zone in case of poorly differentiated carcinoma.

Sharma et al.[11] showed that squamous cell carcinoma was the most common histological type of bronchogenic carcinoma followed by small cell carcinoma. Shetty et al.[12] also showed similar findings. However, Chhajed et al.[13] and Gupta et al.[14] found adenocarcinoma and small cell carcinoma as the most common subtype, respectively. The most common histological subtype in our study was squamous cell carcinoma followed by adenocarcinoma as observed in most of the Indian studies.

Sharma et al.[11] found that the incidence of lung cancer was five times more common in males than in females. But in our study, the male-to-female ratio of lung cancer was 3.52:1. Thus, like in western countries, the incidence of lung cancer is increasing in India.

We found that 14.42% of the patients with lung cancer were non-smokers, which was more than the findings of Hassan et al.[15] (6.8%).

In our study, almost three-fourth of squamous cell carcinoma presented as central lesion on chest X-ray, which was similar to the study findings of Mayo Clinic[16] and Sharma et al.[11] but different from Shetty et al.,[12] who found that the presentation of squamous cell carcinoma was mostly peripheral. According to our observation, adenocarcinoma most commonly manifested as peripheral tumour, which was similar to the studies by Mayo Clinic[16] and Sharma et al.[11] On the contrary, Shetty et al.[12] reported that adenocarcinoma commonly presented as central tumour. The presentation of small cell carcinoma was central radiologically in our study, which was similar to the studies by Mayo Clinic and Marshfield.[17]

In our study, squamous cell carcinoma most frequently manifested as lobar collapse followed by consolidations, which was similar to the studies by Almoudi et al.[18] and Maula et al.[10] Adenocarcinoma in our study commonly presented as peripheral nodules followed by pleural effusion. These findings were quite similar to the study by Sharma et al.,[11] but completely different to Kuriyama and colleagues,[19] wherein they found consolidations in 60% of the adenocarcinoma with no nodular and mediastinal involvement. In our study, the large cell carcinoma presented as mass and collapse, which did not match with the findings of Maula et al.,[10] wherein they reported collapse and effusion as the main presentations of large cell carcinoma. We reported that the most common presentation of small cell carcinoma was mass (75%) followed by collapse, which was similar to the findings of Maula et al.[10]

We found cavitating lesion only in squamous cell carcinoma. This finding was almost similar to the study by Sharma et al.,[11] wherein they found cavitation in all types of cancer but predominantly in squamous cell carcinoma. Calcifications were seen predominantly in small cell carcinoma unlike the study by Shetty et al., wherein they found it most commonly in squamous cell carcinoma. We found hemidiaphragmatic palsy and rib involvement predominantly in squamous cell carcinoma and satellite lesions predominantly in adenocarcinoma. This finding was in contrast to the study by Sharma et al.,[11] wherein they found diaphragmatic palsy, satellite lesion and rib involvement most commonly in small cell carcinoma.

 Conclusion



We found that squamous cell carcinoma and small cell carcinoma commonly presented as central lesions, whereas adenocarcinoma and large cell carcinoma manifested most frequently as peripheral lesions. Chest roentgenography can provide a clue about the pathological cell types of bronchogenic carcinoma.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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