Empyema necessitans, a rare complication of empyema thoracis

rise in temperature was noted. Since, the swelling was confined to soft tissue, contrast enhanced Magnetic Resonance Imaging (MRI) was advised which showed a peripheral rim enhancing, large, multilobulated T1WI hypointense and T2WI hyperintense lesion in right posterior chest wall having multiple internal septations. The lesion was involving the intercostal space and intercostal muscles. Cortical irregularity and altered marrow signal intensity was noted at 6th and 7th ribs of right posterior chest wall. Similar characteristics lesion was noted in the right posterior pleural space which appeared communicating with the posterior chest wall lesion. Ultrasound (US) examination of the swelling was done which showed hypoechoic, multi lobulated mass which showed no vascularity on color flow. Hence, ultrasound guided fine needle aspiration (FNA) was done; from which thick purulent yellowish colored pus was aspirated and was sent for gram stain, acid fast bacillus, culture and sensitivity. Pus culture revealed Mycobacterium tuberculosis. Based on this, thoracotomy with decortication was done. Patient was treated with intravenous antibiotics and discharged home on oral antibiotics with significant improvement (Figure 1 & Figure 2).