CASE 11547 Published on 25.02.2014

Empyema necessitans, a complication of tuberculosis

Section

Chest imaging

Case Type

Clinical Cases

Authors

Ressurreição J, Soares JT, Madaleno P, Portugal P

Centro Hosp. Vila Nova de Gaia,
Radiology,
Rua Conceição Fernandes
4430 Vila Nova de Gaia, Portugal;
Email:joaofres@gmail.com
Patient

78 years, male

Categories
Area of Interest Lung ; Imaging Technique CT, Ultrasound
Clinical History
77-year-old male Caucasian patient was admitted with left-sided chest mass, first noticed 15 days before admission. At physical examination a non-tender tumefaction on the mid-axillary line of left chest wall was perceived. There was no fever, chills or cough. The patient had a clinical history of pulmonary tuberculosis 50 years before.
Imaging Findings
Chest radiography demonstrated a loculated left pleural effusion with associated soft-tissue opacity in the left chest wall (Fig. 1). An abdominal ultrasound (US) was performed in order to better characterize the radiographic findings, showing a subcutaneous fluid collection with fine internal debris, measuring 5 x 3 x 7 cm, that communicated with the pleural cavity through a well-defined tract (Fig. 2 a, b). Imaging findings were further investigated with contrast-enhanced computed tomography (CT) imaging. CT revealed a loculated left pleural effusion with thickened, contrast-enhanced and partially calcified pleural surfaces that communicated with an organized, subcutaneous chest-wall fluid collection (Figures 3a-i).

Both the subcutaneous collection and the pleural effusion were drained and the fluid samples from both cavities were analyzed: they were positive for acid fast bacilli and cultures confirmed the presence of Mycobacterium tuberculosis.

Anti-bacillary treatment was initiated and the patient was discharged totally asymptomatic. Consultation with the thoracic surgeon was scheduled.
Discussion
Empyema necessitans (or empyema necessitatis) is a complication of pulmonary infection, most frequently secondary to Mycobacterium tuberculosis infection reactivation, although it can also occur with actinomycosis and pyogenic bacterial infection [1, 2]. It represents extension of pus from the pleural cavity to the chest wall (most frequently), but also to the bronchi, oesophagus, breasts or retroperitoneum [3, 4].
The patients generally present with an enlarging, occasionally painful, erythematous chest wall mass, most frequently affecting the second through sixth intercostals spaces [5]. Associated respiratory symptoms such as cough or dyspnoea and pleuritic-type chest pain also occur.
While chest radiography can suggest the diagnosis, demonstrating a loculated pleural effusion in a patient with past history of pulmonary tuberculosis presenting with an anterior chest wall mass, the definitive imaging findings are usually seen with CT. Contrast-enhanced CT clearly demonstrates the existence of a communication between the empyema (i.e.: a loculated pleural effusion with thickened and enhancing pleural surfaces) and a well-deliniated chest wall fluid collection with thickened and enhancing walls, representing an abscess [6].
US and CT can also aid in the therapeutic process, guiding the thoracostomy necessary to drain the pleural cavity. Generally there is a good response to tube-thoracostomy and parenteral antibiotic therapy but, in some cases, there is necessity to perform a thoracotomy and pleural decortication to definitely solve the problem [4].
Tuberculous empyema necessitans has a good clinical outcome when managed accurately and promptly, with an associated mortality rate less than 5% [7]. Accurate diagnosis based on imaging evaluation and adequate antibiotic therapy are crucial for management of this disease.
Differential Diagnosis List
Empyema necessitans as manifestation of tuberculosis
Actynomycosis
Mesothelioma
Final Diagnosis
Empyema necessitans as manifestation of tuberculosis
Case information
URL: https://www.eurorad.org/case/11547
DOI: 10.1594/EURORAD/CASE.11547
ISSN: 1563-4086