Evaluation of HRCT for the Differential Diagnosis of Pneumonia-Like Consolidation Pattern of Pulmonary MALT Lymphoma from Lobar Pneumonia

PURPOSE: To assess the performance of high-resolution computed tomography (HRCT) in discriminating the consolidation pattern of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma from lobar pneumonia. PATIENTS AND METHODS: This retrospective study comprised 26 patients with pathologically confirmed consolidation pattern of pulmonary MALT lymphoma (12 men and 14 women; mean age, 59.4±12.1 years) and 36 patients with lobar pneumonia confirmed by body fluids or respiratory secretion culture (16 men and 20 women; mean age, 41.8±26.3 years). Two radiologists independently evaluated the CT images. The effectiveness of these variables in distinguishing lobar pneumonia from MALT lymphoma was analyzed using logistic regression analysis. RESULTS: The average age of lobar pneumonia patients was younger than that of MALT lymphoma patients (p=0.002). The respiratory symptom was more common in lobar pneumonia than MALT lymphoma (p=0.002). Signs of bronchiectasis within the consolidation and bulging of interlobar fissure occurred significantly more often in MALT lymphoma than pneumonia (69.2% vs 11.1%, p<0.0001; 46.2% vs 19.4%, p=0.024). We used the predictors with p<0.05 (age, respiratory symptoms, bronchiectasis, and bulging of interlobar fissure) to construct a logistic regression model. The area under curve (AUC), negative predictive value (NPV), positive predictive value (PPV), sensitivity, specificity, and accuracy were 0.891, 84.21%, 83.33%, 88.89%, 76.92%, and 83.87% for discriminating lobar pneumonia from MALT lymphoma. CONCLUSION: Middle-aged, presence of mild clinical symptoms, bronchiectasis and bulging of the interlobar fissure on chest CT images are potential markers to distinguish pulmonary MALT lymphoma from lobar pneumonia.