Aggressive Presentation of Streptococcus constellatus

Abstract

The Streptococcus anginosus group (SAG) consists of three bacteria (Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus) that are known commensals of the upper respiratory, digestive, and reproductive tracts. While a rare occurrence, these bacteria have the capability of causing devastating pyogenic infections and ensuing abscess formations. It is often difficult to distinguish this group as a contaminant or the offending organism (as it is often cultured in respiratory specimens); therefore, it is important to understand the risk factors, clinical presentation, and diagnostic findings that can provide a more accurate picture to identify the organism. Published literature pertaining to the SAG group has rarely documented any invasive surgical intervention that was undertaken for treatment. We describe a case of a 59-year-old male who presented for persistent chest pain and profuse productive cough weeks after he was diagnosed with a left lower extremity deep vein thrombosis and right-sided pulmonary embolism. The patient was found to have a rapidly evolving Streptococcus constellatus right middle lobe lung abscess complicated by a right hemithorax empyema. Management included an exploration of the right chest, decortication, parietal pleurectomy, and partial excision of the right middle lobe. Subsequently, the patient completed four weeks of antibiotics with ertapenem.

Keywords: deep vein thrombosis (dvt); prolonged antibiotics; pulmonary decortication; streptococcus constellatus.

Figure 1. CT of the chest showing a 4.0 x 4.6 cm cavitating lesion in the right middle lobe with associated, surrounding ground-glass opacities in the transverse plane.

Figure 2. CT of the chest showing a 4.0 x 4.6 cm cavitating lesion in the right middle lobe with associated, surrounding ground-glass opacities in the coronal plane.

Figure 3. CT of the chest showing significant interval worsening of cavitary right middle lobe lesion, now demonstrating an internal air-fluid levels and gas-filled septations and measuring up to 18.6 cm. This likely represents evolution of lung necrosis with probable superimposed infection.

Figure 4. CT of the chest showing significant interval worsening of cavitary right middle lobe lesion, now demonstrating an internal air-fluid levels and gas-filled septations and measuring up to 18.6 cm. This likely represents evolution of lung necrosis with probable superimposed infection. New small hydropneumothorax along the convexity of the right upper lung is also noted.

Figure 5. CT of the chest one month later shows a small residual collection of air and possible fluid in the right lateral lower lung near the major fissure in the region of the previous large abscess.