bubble_chart Overview

Empyema caused by infection with subcutaneous node bacteria is referred to as subcutaneous node empyema. It often develops into chronic empyema due to prolonged delays in diagnosis and treatment.

bubble_chart Etiology

The routes of subcutaneous node bacteria invading the thoracic cavity: infection caused via lymphatic or blood circulation, direct invasion of the pleura by pulmonary subcutaneous node lesions, or rupture of the lesions introducing subcutaneous node bacteria directly into the thoracic cavity while simultaneously allowing gas to enter, forming pyopneumothorax, or even bronchopleural fistula.

Empyema is also a complication of artificial pneumothorax or surgical treatment of pulmonary subcutaneous nodes. Bone subcutaneous nodes or chest wall subcutaneous nodes can also invade the thoracic cavity.

bubble_chart Pathological Changes

In the initial stage of subcutaneous node infection in the thoracic cavity, acute inflammation, congestion, and exudation occur, forming scattered subcutaneous node nodules. The pleural effusion is serous, containing white blood cells and fibrin. Over a prolonged period, it gradually progresses to chronic subcutaneous node empyema, with thick and rigid fibrous plaques that often calcify. The contraction of the fibrous plaques narrows the intercostal spaces, deforms the ribs into triangular cross-sections, atrophies the intercostal muscles, and causes the spine to protrude toward the healthy side. Empyema can be localized or total. Sometimes, the empyema ruptures into the intercostal space, even invading the ribs, forming a cold abscess or breaking through the skin to create a sinus that continuously discharges pus over a long period.

bubble_chart Clinical Manifestations

The clinical manifestations of subcutaneous nodular empyema are highly variable. Most cases have an insidious onset, with weakness and low-grade fever as the main symptoms, followed by night sweats, chest tightness, and dry cough. In the early stages of empyema, the absorption capacity of the pleural membrane is strong, and toxic symptoms are more pronounced. If pus accumulation is significant, symptoms such as shortness of breath and difficulty breathing may also occur. When a bronchopleural fistula develops, it can cause irritating cough, along with purulent sputum that is position-dependent. Coughing and purulent sputum increase when lying on the unaffected side. If subcutaneous nodular dissemination occurs due to a bronchopleural fistula, toxic symptoms become very severe, and the condition is critical. If secondary infection occurs, high fever and leukocytosis may develop, with symptoms resembling those of acute empyema.

bubble_chart Diagnosis

The radiographic findings are essentially the same as those of chronic empyema. Cases with subcutaneous node lesions in the contralateral lung are easier to diagnose, whereas those with subcutaneous node lesions on the affected side are often obscured by effusion, making it difficult to determine their nature. Thoracentesis yields relatively thin pus, which may contain caseous material. Definitive diagnosis requires the identification of subcutaneous node bacteria in the pus, but this is rarely achieved in clinical laboratory tests. Therefore, when the pus contains abundant lymphocytes or routine bacterial cultures are negative, subcutaneous node empyema should be considered. In patients with subcutaneous node disease complicated by empyema, the diagnosis of subcutaneous node empyema should be prioritized.

Tomography can reveal the size of the empyema cavity and also demonstrate the presence and extent of subcutaneous node lesions in the lung. CT scans provide even more detailed information about the empyema cavity and subtle changes in the lesions.

bubble_chart Treatment Measures

The treatment of tuberculous empyema primarily involves anti-tuberculosis therapy, often requiring a combination of three drugs from isoniazid, rifampin, streptomycin, and ethambutol. In the early stages of tuberculous empyema, when there is minimal pus accumulation, aggressive and effective anti-tuberculosis treatment, along with improved nutrition and adequate rest, may lead to absorption and improvement. If there is a large amount of fluid, thoracentesis can be performed to promote absorption, but care must be taken to prevent secondary infection. Closed thoracic drainage should be avoided before secondary infection becomes uncontrollable with medication, as the pathological changes of tuberculosis cause fibrosis of lung tissue, preventing expansion. Closed drainage may fail to eliminate the empyema cavity and instead increase the risk of mixed infection.

If tuberculous empyema is complicated by bronchopleural fistula or severe mixed infection, aggressive and adequate drainage must be combined with intensive antibiotic therapy. Otherwise, the condition may become uncontrollable and could worsen pulmonary dissemination. Surgical treatment should be considered only after the condition stabilizes.

The main surgical procedures for tuberculous empyema are thoracoplasty and pleuropneumonectomy. Decortication of the pleura can only be performed if there are no pulmonary lesions and no bronchial stenosis caused by endobronchial tuberculosis. Otherwise, the lung may fail to expand, the empyema cavity may persist, or pulmonary lesions may worsen post-expansion, leading to cavity formation and surgical failure.

Surgery should be performed after at least three months of anti-tuberculosis therapy, once the tuberculosis is under control and the condition has stabilized.