Empyema necessitans is a rare complication of empyema thoracis where the pleural infection extends out of the thorax into the chest wall or surrounding soft tissues. It can be caused by various organisms such as mycobacteria, actinomyces, or fungi. Patients may present with chest pain, erythema, swelling over the chest wall, and symptoms of pulmonary infection. Imaging such as chest X-ray, CT, or MRI can show fluid densities extending into subcutaneous tissues from the pleural space. Treatment involves surgical drainage of abscesses followed by cultures to identify the causative organism and administer appropriate antibiotics.

1. Empyema
Necessitans
Dr. Manmohan Bir Shrestha
For Radiology

2. Empyema Necessitans / Necessitasis
Rare long term complication of empyema thoracis
refers to extension of a pleural infection out of the thorax and
into the neighboring chest wall and surrounding soft tissues
 extension of an empyema out of the pleural cavity.
With the advent of antimicrobials, its incidence has
decreased

3. Pathology
 It may either occur due the virulence of the organism or may be facilitated by
previous thoracic surgery (e.g. thoracotomy) or trauma allowing infection to
track through.
 It occurs commonly to subcutaneous tissues of the chest wall, but can also
spread to involve other sites such as
 esophagus
 breast
Peritoneal & retroperitoneal region
 pericardial region
paravertebral regions.
 The resultant subcutaneous abscess may eventually rupture through the skin.
 Can even cause osteonecrosis of the affected rib.

4. Causative organisms
 Mycobacterium tuberculosis – most common
Actinomyces
Blastomycosis
Aspergillus
Nocardia
Mucormycosis
Fusobacterium

5. Clinical feature - varies
Sign & symptoms of pulmonary tuberculosis
Chest pain
Erythema & swelling over chest wall.

6. Imaging modalities
Chest x-ray
Ultrasound
CT Scan
MRI

7. Plain radiograph
are often non-specific and sometimes even normal
may suggest soft tissue density in chest wall
can resemble pleural effusion/empyema thoracis
can show features of consolidation

8. CT Scan
Fluid density in pleural space & extending into
subcutaneous tissues in the chest wall or
elsewhere in abdomen
Shows bone erosions well
Post contrast – rim enhancing fluid collections.

9. MRI
T1WI – Iso to hypointense
T2WI – hyperintense
Post contrast – rim enhancing

10. Case of 40 yrs. female patient
Complaints
Fever, chills & sweats for one week
On examination
Palpable, non-tender subcutaneous mass over the
right anterior chest wall.

12. Treatment
Surgery for the drainage of abscess
with right anterior thoracotomy
Culture of drained fluid
Growth of Methicillin Resistant
Staphylococcus aureus

13. 25 yrs. Male with fever & chest pain for few
days

14. 20 yrs. male Complaints of
- Mass on posterior aspect of left back for 2
months.
- Low grade fever for same duration

15. Culture of drained fluid showed acid-fast bacilli confirming the diagnosis
of tuberculosis

16. 56 yrs. Old male
Complaints
3 weeks of progressive, localized, right-sided posterior chest wall
pain and swelling.
No fevers or chills, productive cough, hemoptysis, change in weight
On examination
hard and fixed mass on the right posterior chest wall at the level of
the 11th rib with minimal tenderness to palpation.

18. Pre-operative Post-operative

19. Culture report confirmed actinomycosis.
Follow up after 6 weeks

20. Presenting Case, 18 yrs. Old young male