DOES THICKNESS REALLY MATTER? DIAGNOSTIC DILEMMAS IN CAVITARY LESIONS

Abstract

TOPIC: Lung Cancer TYPE: Medical Student/Resident Case Reports INTRODUCTION: A pulmonary cavity is a gas-filled space seen as a lucency within a pulmonary consolidation, a mass, or a nodule. The differential for a solitary cavity of the lung includes anaerobic lung abscess, fungal infections, tuberculosis and malignancy. Wall thickness <4 mm has been shown to be caused by benign processes while thickness >15 mm are usually malignant. We describe the case of a former smoker in whom an infection was masking a cavitary squamous cell carcinoma of the lung. CASE PRESENTATION: A 75 year-old former smoker presented to the ER with hemoptysis for 1 week. He was afebrile with BP 90/50 and HR 124. WBC count was 17.8K/L. CT Chest revealed a 9.7 cm irregular cavitary mass in the right upper lobe of the lung with thick walls measuring 29 mm and evidence of invasion into the right hilum and chest wall causing rib fractures. Exam was significant for foul-smelling breath and poor dentition with gross aspiration while lying flat. Bronchoscopy demonstrated thick purulent secretions in the RUL and advancement into RUL takeoff with the bronchoscope led directly inside the cavity, revealing thick, friable walls. BAL and endobronchial brushings were obtained. Given patient's risk factors for aspiration and imaging findings, there was concern for possible anaerobic lung abscess. BAL cultures were polymicrobial. He received antibiotics and improved. However, BAL cytology and endobronchial brushing demonstrated malignant cells. Pathology from a CT-guided biopsy of the lesion confirmed squamous cell carcinoma of the lung. DISCUSSION: Several features of our patient's clinical presentation were suggestive of anaerobic lung abscess including aspiration, poor dentition, halitosis and leukocytosis. However, primary lung cancer remains the most frequent cause of a solitary cavitary lung lesion. Squamous cell carcinoma is the most common subtype to cavitate due to tumoral necrosis, in up-to 82% of patients. Features that can raise suspicion for malignancy as an etiology of a lung cavity include thickness of cavity wall >15 mm with irregular internal contours, upper lobe location and chest wall invasion, all of which were present in our patient. Our case highlights the importance of maintaining a high index of suspicion for underlying malignancy in smokers with cavitary lesions, despite an overwhelming clinical picture of infection. CONCLUSIONS: Cavitary lung lesions with high-risk radiological features such as wall thickness>15 mm should prompt accelerated work-up for malignancy to minimize high morbidity and mortality. REFERENCE #1: Gafoor K, Patel S, Girvin F, Gupta N, Naidich D, Machnicki S, Brown KK, Mehta A, Husta B, Ryu JH, Sarosi GA, Franquet T, Verschakelen J, Johkoh T, Travis W, Raoof S. Cavitary Lung Diseases: A Clinical-Radiologic Algorithmic Approach. Chest. 2018 Jun;153(6):1443-1465. doi: 10.1016/j.chest.2018.02.026. Epub 2018 Mar 6. PMID: 29518379. DISCLOSURES: No relevant relationships by Roxanne GarciaOrr, source=Web Response No relevant relationships by Sumit Patel, source=Web Response No relevant relationships by Nehan Sher, source=Web Response