From the Guidelines
Tuberculosis (TB) causes axillary lymphadenitis and hepatomegaly through its dissemination and inflammatory response patterns, which can lead to significant morbidity and mortality if not properly treated. TB, caused by Mycobacterium tuberculosis, typically enters the body through inhalation and establishes primary infection in the lungs. From there, the bacteria can spread via lymphatic channels to regional lymph nodes, including axillary lymph nodes, especially in cases of upper lobe pulmonary TB or direct inoculation through the skin. In the lymph nodes, TB triggers a granulomatous inflammatory response, causing the nodes to enlarge (lymphadenitis), become firm, and sometimes develop caseous necrosis or form cold abscesses, as noted in the treatment guidelines for drug-susceptible tuberculosis 1.
Hepatomegaly occurs when TB disseminates hematogenously to the liver, where the bacteria stimulate granuloma formation. These granulomas contain macrophages, epithelioid cells, and Langhans giant cells surrounding the bacteria, leading to hepatic inflammation and enlargement. This process is particularly common in miliary or disseminated TB, where multiple small granulomas form throughout the liver parenchyma. The immune response to TB, characterized by delayed-type hypersensitivity reactions, contributes significantly to the tissue damage and organ enlargement seen in both conditions. Key considerations in managing TB-related lymphadenitis include the potential for lymph node enlargement during or after therapy without evidence of bacteriological relapse, as well as the role of aspiration in managing large, fluctuant lymph nodes, although therapeutic lymph node excision is generally not indicated except in unusual circumstances 1.
Some key points to consider in the management and pathogenesis of TB-related axillary lymphadenitis and hepatomegaly include:
- The potential for lymphatic spread of TB to axillary lymph nodes
- The formation of granulomas in affected organs, including the liver
- The role of the immune response in tissue damage and organ enlargement
- The importance of appropriate treatment regimens, such as the 6-month regimen recommended for drug-susceptible tuberculous lymphadenitis 1, in preventing long-term morbidity and mortality.
From the Research
TB Infection and Lymphadenitis
- TB can cause axillary lymphadenitis, as seen in a case where a patient presented with progressive, painless, left supraclavicular and axillary lymph node enlargement 2.
- The infection can lead to granulomatous lymphadenitis of uncertain etiology with sarcoid-type and tuberculoid-type granulomas 2.
- Tuberculous lymphadenitis is the most common extrapulmonary manifestation of tuberculosis, and it can mimic other pathologic processes, making diagnosis challenging 3.
Hepatomegaly and Abdominal Involvement
- TB can also cause hepatomegaly, as reported in a case of unusual miliary tuberculosis presenting with generalized lymphadenopathy and abdominal involvement 4.
- The patient had extensive lymphadenopathy, bilateral pulmonary miliary reticulonodular infiltrates, pleural effusion, hepatomegaly with low density, macronodular hypodense areas in spleen, ascites, peritoneal irregularity, and thickening of bowel walls 4.
- The infection can lead to caseating granulomatous lymphadenitis, which is consistent with tuberculosis 4.
Treatment and Management
- Standard antituberculosis treatment with isoniazid, rifampicin, pyrazinamide, and ethambutol can be effective in treating TB lymphadenitis 2, 5.
- Treatment monitoring is complex due to the peculiar behavior of TB lymph nodes, and surgical therapy along with antituberculosis medication can be beneficial in selected patients 3.
- The World Health Organization (WHO) has developed a novel strategy called DOTS (directly observed treatment, short-course) to control TB 5.