Tuberculous empyema necessitatis in a man infected with the human immunodeficiency virus. (Case Reports).

ABSTRACT: Empyema necessitatis is a collection of inflammatory tissue that ruptures spontaneously through a weakness in the chest wall into surrounding soft tissues. Although empyema necessitatis can be caused by a number of infectious agents, mycobacteria are the most frequently implicated. Empyema was a much more common complication of pulmonary tuberculosis in the preantibiotic era than it is today. We describe a 22-year-old man with human immunodeficiency virus (HIV) infection who had tuberculous empyema necessitatis and was successfully treated with surgical debridement and antibiotic therapy.

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EMPYEMA NECESSITATIS is a collection of inflammatory tissue that usually extends directly from the pleural cavity into the thoracic chest wall, forming a mass in the extrapleural soft tissues, following anatomic boundaries. (1) Gullan de Baillon first described it in 1640, when it developed after the spontaneous rupture of a syphilitic aneurysm. (2) It was much more common in the preantibiotic era than it is today. Herein, we report a case of an HIV-positive man with a soft thoracic mass due to tuberculous empyema necessitatis.

CASE REPORT

A 22-year-old man known to have the acquired immunodeficiency syndrome was admitted to our hospital with a 1-month history of chest pain, cough, weight loss, dyspnea, and high fever. He had had follow-up since 1994 for HIV infection. In June 1997, he had Pneumocystis carinii pneumonia, but he refused to take antiretroviral therapy. His last CD4 cell count was 35/mL, and HIV-RNA viral load was 225,336 copies/mL. Physical examination revealed a soft, painful subcutaneous mass with crepitus in the left chest wall. Laboratory values included hemoglobin 9.6 g/dL, hematocrit 27%, white blood cell count 1,900/[mm.sup.3], erythrocyte sedimentation rate 60 mm/hr, sodium 127 mEq/L, and lactate dehydrogenase 524 U/L. Arterial blood gas values showed severe hypoxemia and respiratory acidosis. Three blood cultures were negative. A chest radiograph showed a left pleural effusion. Computed tomography (CT) revealed a left-sided, well-encapsulated, low-attenuated pleural collection with extension through the parietal pleura into the adjacent soft tissues and the superolateral chest wall (Figure). An exudative pleural effusion was aspirated, and acid-fast bacilli were found in the effusion and in the bronchoalveolar lavage fluid. Subsequent cultures were positive for Mycobacterium tuberculosis, and all tuberculostatic drugs tested showed high sensitivity. Tuberculous empyema necessitatis was diagnosed. Surgical debridment and appropriate antituberculosis therapy for 6 months were effective.

DISCUSSION

In 1940, Sindel (3) reviewed 115 cases of empyema necessitatis. Eighty-four of them were caused by tuberculosis and 31 by pyogenic infections, mainly Streptococcus pneumoniae. Actually, empyema necessitatis is an extremely unusual complication of empyema, and most of the scattered case reports over the past 30 years have described immunocompromised patients or patients with underlying tuberculosis. (4-5)

Tuberculous empyema is most commonly a result of rupture of a subpleural caseous focus into the pleural space. Rarely, it is due to hematogenous spread from involved thoracic lymph nodes or from a subdiaphragmatic focus. Although accounting for only 10% of pleural empyemas, M tuberculosis was responsible for 73% of cases of empyema necessitatis. Rarer causes of empyema necessitatis include malignancy, other pyogenic lung abscesses (due to S pneumoniae, Staphylococcus species, gram-negative bacilli, and polymicrobial infections), blastomycosis, and antinomycosis. (4) If tuberculous empyema is inadequately treated, it may spontaneously perforate the pleura and extend through fascial planes. Other sites of empyema extension include the vertebral column, paravertebral soft tissues, retroperitoneum, bronchus, mediastinum, breast, diaphragm, and more rarely the esophagus, flank, groin, and pericardium. In empyema necessitatis, patients can have pleuritic chest pain worsening with deep inspiration and rarely a nonp roductive cough. Its overall mortality is 66%, and involvement of the psoas and lumbar regions is nearly 100%. (4)

Radiography shows a soft tissue mass in the chest wall with or without bony destruction. Computed tomography shows a thick-walled, well-encapsulated pleural mass associated with an extrapleural mass in the chest wall, highly suggestive of tuberculous empyema necessitatis. (6,7) Although direct communication between the pleural and chest wall collections is rarely shown, CT is helpful in the detection and characterization of this complication of pleural tuberculosis. (4) In addition, osteolytic lesions with cortical disruption and costal or sternoclavicular joint lesions can be seen.

In summary, although tuberculous empyema necessitatis is now rare, it is important to consider this process in immunocompromised patients with a soft tissue mass of the chest and palpable crepitus. Typical CT findings include a thick-walled, well-encapsulated pleural mass associated with an extrapleural mass in the chest wall.

References

(1.) Perez-Castrillon JL, Gonzalez C, del Campo F, et al: Empyema necessitatis due to Actinomyces odontolyticus. Chest 1997; 111:1144

(2.) Dvali L, Quan C, Pugash R, et al: Empyema necessitans presenting as a gas-forming cellulitis in an HIV-positive man: case report. Can J Plast Surg 1999; 7:53-57

(3.) Sindel EA: Empyema necessitatis. Bull Seaview Hosp 1940; 6:1-49

(4.) Eschelman DJ, Gibbens DT, Fielding JR, et al: Chest case of the day. AJR 1991; 156:1295-1296

(5.) Peterson MW, Austin JHM, Yip CK, et al: CT findings in transdiaphragmatic empyema necessitatis due to tuberculosis. J Comput Assist Tomogr 1987; 11:704-706

(6.) Glicklich M, Mendelson DS, Gendal ES, et al: Tuberculous empyema necessitatis: computed tomographic findings. Clin Imaging 1990; 14:23-25

(7.) Bhatt GM, Austin HM: CT demonstration of empyema necessitatis. J Comput Assist Tomogr 1985; 9:1108-1109

RELATED ARTICLE: KEY POINTS

* Empyema necessitatis is a collection of inflammatory tissue that ruptures spontaneously through a weakness in the chest wall to surrounding soft tissues.

* We describe a 22-year-old HIV-positive man who presented with tuberculous empyema necessitatis.

* Although tuberculous empyema necessitatis is now rare, it is important to consider this process in immunocompromised patients with a soft tissue mass of the chest with palpable crepitus.

From the Infectious Diseases Division, Internal Medicine Department, Hospital of San Juan, Alicante, Spain.

Reprint requests to Francisco Jover Diaz, C/Amadeo de Saboya, 2, 5[degrees] B. 03012. Alicante, Spain.