Unilateral Unusual Post-traumatic Breast Pain and Swelling in a Young Adult: A Case of Tuberculous Empyema Necessitans.

Empyema necessitans is a very rare and morbid complication of pleural empyema. It is defined as the extension of pleural infection to the chest wall and surrounding soft tissues. Our case highlights an unusual presentation of empyema necessitans in a 29-year-old man. The patient had no prior comorbidities and presented to the emergency department with a 15-day history of growing left unilateral chest pain and swelling. This was initially clinically misdiagnosed as a post-traumatic hematoma. Contrast-enhanced chest CT scan allowed a diagnosis and the ruling out of the main differentials, such as skeletal lesions extending to adjacent structures but also benign and malignant soft tissue masses. The treatment involved surgical drainage of the abscess. Microbiological analysis of the abscess content identified Mycobacterium tuberculosis as the causative pathogen. The patient was subsequently treated with antituberculous drugs, leading to a favorable clinical outcome. This case outlines the importance of an enhanced chest CT scan in making an early diagnosis, defining the extent of the disease, and discussing differentials, all of which are paramount to better results with fewer complications. Moreover, it highlights the fact that blunt trauma may facilitate the formation of a fistula when an underlying infection is present.