|CASE IN POINT - CLINICS IN PULMONARY MEDICINE
|Year : 2017 | Volume
| Issue : 3 | Page : 186-188
Bronchogenic carcinoma masquerading as lung abscess
Vidushi Rathi1, Pranav Ish2, Gulvir Singh1, SN Gaur1
1 Department of Pulmonary Medicine, Vallabhbhai Patel Chest Institute, Delhi, India
2 Department of Pulmonary, Critical Care and Sleep Medicine, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
|Date of Web Publication||30-Jan-2018|
B-1, Green Park Extension, New Delhi - 110 016
Source of Support: None, Conflict of Interest: None
Lung abscesses are necrotizing consolidation of lung parenchyma which usually require a prolonged course of antibiotics. However, underlying secondary etiologies of lung abscess such as malignancy should be sought for, especially in unresponsive cases. Clinicoradiological correlation often assists, however, bronchoscopy and histopathology eventually confirm the diagnosis. We present a case of lung abscess who after initial response to antibiotics was subsequently diagnosed as squamous cell carcinoma of the lung.
Keywords: Carcinoma, lung abscess, malignant cavity
|How to cite this article:|
Rathi V, Ish P, Singh G, Gaur S N. Bronchogenic carcinoma masquerading as lung abscess. Astrocyte 2017;4:186-8
| Introduction|| |
A lung abscess is a localized area of destruction of lung parenchyma, usually caused by poly-microbial infection that results in tissue necrosis and suppuration. Based on the underlying etiology, lung abscess can be classified into primary, as seen in aspiration and necrotizing pneumonia, or secondary as seen in bronchial obstruction, coexisting lung diseases, and direct or hematogenous spread. However, an underlying malignancy can masquerade as an abscess and a high index of suspicion should be kept for early diagnosis and treatment.
| Case Report|| |
A 55-year-old male patient presented with complaints of productive cough, right-sided chest pain, and fever for 20 days. Cough was associated with foul smelling, purulent sputum, and fever was high grade documented to 101°F. Patient had no history of diabetes or hypertension. He was a chronic smoker with 30 pack-years of smoking history and a diagnosed case of chronic obstructive pulmonary disease (COPD), for which he was irregularly taking an inhaler containing salmeterol and fluticasone.
On physical examination, patient was found to be tachypnic (respiratory rate, 22) and had a temperature of 102°F. General examination revealed pallor but no lymphadenopathy, digital clubbing, or pedal edema. On auscultation, bronchial breath sounds were heard in the right interscapular and axillary areas. The chest radiograph [Figure 1] showed a large, thick-walled cavity with air fluid level in the right upper zone. Complete blood counts displayed leukocytosis and anemia [Table 1]. Sputum was negative for acid fast bacilli; however, Acinetobacter spp. was isolated in pyogenic culture. Human immunodeficiency virus status was nonreactive. He was initiated on intravenous antibiotics as per the sensitivity pattern. Despite being on antibiotic therapy, high-grade fever persisted, and a follow-up chest radiograph revealed an increase in cavity size. Computed tomography (CT) of the thorax [Figure 2]a and [Figure 2]b confirmed the finding of lung abscess in the right upper lobe (RUL), with abrupt cut-off of the RUL bronchus. Fibreoptic bronchoscopy (FOB) visualized a growth in the RUL bronchus [Figure 3]. Repeated gentle suction led to the drainage of thick, brown pus from RUL. Bronchial aspirate cultured methicillin-resistant Staphylococcus aureus, and exfoliative cytology was not suggestive of any atypical cells. Post FOB, there was marked resolution in the size of cavity [Figure 1]b and fever subsided. The patient was then discharged on oral linezolid.
|Figure 1: (a) Chest radiograph demonstrating a large cavity with air-fluid level in the right upper zone. (b) Post-bronchoscopic aspiration repeat chest radiograph taken five days later demonstrating diminution in fluid and size of cavity.|
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|Figure 2: (a) CT Thorax lung window (coronal section) showing large, thick walled irregular cavity occupying right upper lobe with peripheral areas of consolidation. (b) CT Thorax lung window (axial section) showing thick walled cavity with air fluid level.|
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|Figure 3: Fiberoptic bronchoscopy projection at the right upper lobe bronchus depicting a large fungating mass.|
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Two weeks later, due to persistent cough, poor appetite, loss of weight, and low-grade fever, the patient presented to another hospital where his chest X-ray displayed persistent lung cavity. On repeat bronchoscopy, an intraluminal growth was seen in right upper lobe bronchus. Biopsy from the growth uncovered squamous cell carcinoma [Figure 4]a and [Figure 4]b.
|Figure 4: Medium power (x40) microscopic view showing well differentiated hyperchromatic malignant epithelial cells and keratinization (marked K) suggestive of well differentiated squamous cell carcinoma.(b) High power (x100) microscopic view showing malignant epithelial cells with dense cytoplasm and hyperchromatic nucleus with evidence of mitosis (marked M).|
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| Discussion|| |
Fever, purulent sputum, and leukocytosis are often seen in infective etiology of lung parenchymal disease which may present as consolidation or lung abscess. Clinical response to broad-spectrum antibiotics is usually seen in 3–4 days even though radiological resolution may take weeks to months. In this case, clinical features and investigations steered towards an infectious etiology. However, poor clinical response despite appropriate antimicrobial therapy raises suspicions of a secondary pathology. Cavitating bronchogenic carcinoma can mimic lung abscess on CXR and CT images. Further, lung cancer and abscess may occur together as necrotic tissue in tumor may become infected or tumor may itself cause pooling of secretions distally due to physical obstruction of the airways. CT findings of lung cancer may be similar to those of lung abscesses, as bronchial obstruction and vascular involvement with resulting ischemia can lead to tumor necrosis in cases of malignancy. Therefore, it can be difficult to distinguish between lung cancer lesions and lung abscesses on CT. Certain features such as thicker walls and irregular inner contours favour a malignant process. A recent retrospective analysis of CT findings in solitary cavities concluded maximum wall thickness, more than or equal to 24 mm and less than or equal to 7 mm, among the best criteria to differentiate between malignant and benign lung cavities, respectively.
Bronchoscopy can be done in nonresolving cases of lung abscess to look for underlying malignancy. FOB is indicated in patients with lung abscess who had an increasing cavity size or worsening clinical symptoms despite adequate antimicrobial cover.
This patient had a typical history suggestive of infective etiology of lung abscess which even responded to bronchoscopic drainage and appropriate antibiotics. However, a history of smoking with constitutional symptoms was suggestive of an underlying sinister pathology, which was subsequently diagnosed with bronchoscopic biopsy.
Hence, lung abscess not responding to antibiotic therapy adequately should be proactively investigated with bronchoscopy as underlying malignancy may be exposed. A high index of suspicion can help in timely diagnosis and treatment, which largely determines the prognosis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]