045. Empyema necessitatis in non immunocompromised patient

Background: The aim is to present a case with recurrent purulent discharge from the thoracic wall mass.

Case report: A 64-year-old patient, current smoker (30 p/year), with a right anterior thoracic wall mass that has been present for two months was examined in surgical outpatient department. He had incision and drained pass material. Three months later, due to a new lesion adjacent to the mass already drained, an Echo of his right thoracic wall revealed a fistula in thoracic wall. Chest CT scan performed and revealed cystic subcutaneous collection in the right lateral thoracic wall at the level of the diaphragm (56×23 mm²). Further incision and drainage were performed and broad spectrum antibiotics were administered. After the third relapse with purulent discharge through the lesion, the patient sustains surgical wash out of the pleura cavity and chest wall. All this period of time the patient presented low grade fever with no other symptoms. Exudate pleural fluid was revealed that was acid fast bacillus positive with increased Adenosine Deaminase levels (ADA =147 IU/L). Both cultures and molecular test confirmed Mycobacterium tuberculosis (MTb) sensitive to primary antituberculous medication. The patient underwent six months treatment. Immunology showed that the patient was non immunocompromised.

Conclusions: Rarely used term Empyema Necessitatis means that an empyema extends through the parietal pleura into the surrounding tissues. It is commonest between immunosuppressed patients and is usually located on the anterior chest wall between the second and sixth intercostal spaces. The main causative agent is Mycobacterium tuberculosis (approximately 70% of cases) with actinomyces being the next most likely. Chest CT scan is considered imaging test of choice. Treatment consists of drainage of the abscess and antituberculous regimen. Empyema Necessitatis should always be included in the differential diagnosis when evaluating a chest wall mass.

Keywords: Medical thoracoscopy; empyema; pleural fluid