SESSION TITLE: Imaging Posters
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM
PURPOSE: Lung nodules present a significant challenge for clinicians and especially acute in areas where lung nodules due to Coccidioidomycosis can mimic lung cancer. While calculators using both clinical and radiographic criteria are available to assist clinicians, we have found them to have poor specificity in our Coccidioidomycosis endemic areas. In this study we compare and contrast the radiological features differentiating Coccidioidomycosis lung nodules from lung cancer.
METHODS: Between December 2009 and June 2013, we saw 1100 patients with lung nodules. 302 of these patients had confirmed diagnosis of lung cancer (n=192) or Coccidioidomycosis (n=110). We de-identified the chest CT scans for these 302 patients, and two chest radiologists read the films using a standardized system for data collection. The results were analyzed using SPSS Statistical software.
RESULTS: While nodule diameter was higher in lung cancer patients (4.2 ±2.5 cm) than Cocci patients (2.9 ± 1.6 cm), more than half of the nodules due to Cocci were greater than 2 cm. The nodules did not differ by density or by calcification on CT scan. While slightly more Cocci nodules were cavitary (25% versus 8%), the thickness of the cavity wall did not differ (4.79 ± 2.69 mm vs 4.39 ± 2.9). Satellite lesions were more common in Cocci (59% vs. 14% p=.0001); presence of chronic lung disease on CT was more common in lung cancer (66% vs. 19% p=.0001); and spiculated borders were more common in lung cancer (45% vs. 22% p.001). Among those with chronic lung disease on CT scan, emphysema was most common (55%). Mediastinal adenopathy was slightly more common among cancer patients (62% vs 57% p=.035). Multiple lung nodules were common in both groups but slightly more in Cocci patients (73% vs. 62%). Lung cancer was predominantly an upper lobe disease (59% vs. 42%) while Cocci was slightly more common in the lower lobes (49% vs. 35%).
CONCLUSIONS: Our study confirms the significant radiographic overlap between lung nodules due to Cocci and those due to lung cancer. However, we also identified some significant radiographic differences that may be incorporated into the clinical decision-making that impact the approach to nodules in an endemic area.
CLINICAL IMPLICATIONS: Lung nodules will continue to present clinical challenges especially as lung cancer screening is more widely adopted. Our study highlights the need to critically analyze the etiology of lung nodules in different geographic areas with unique non-malignant causes of lung nodules.
DISCLOSURE: The following authors have nothing to disclose: Reza Ronaghi, Ali Rashidian, Paul Mills, Kurt Hildebrandt, Keith Carson, Michael Peterson
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