Should a patient with a calcified granuloma and calcified lymph nodes, suggestive of prior granulomatous disease, be tested for Tuberculosis (TB) and sarcoidosis?

From the Guidelines

Yes, a patient with a calcified granuloma and calcified lymph nodes, suggestive of prior granulomatous disease, should be tested for Tuberculosis (TB) and sarcoidosis.

Key Considerations

• The presence of calcified granulomas and lymph nodes suggests prior granulomatous disease, which can be caused by TB or sarcoidosis 1.
• According to the American Thoracic Society, patients with radiographic findings consistent with prior pulmonary tuberculosis, such as calcified granulomas, are at increased risk for the subsequent development of active tuberculosis 1.
• However, the presence of calcified granulomas alone does not necessarily indicate active TB, and further testing is needed to rule out active disease 1.
• Sarcoidosis is a multisystem granulomatous disease that can present with similar radiographic findings, and diagnosis is often based on a combination of clinical, radiographic, and histopathological findings 1.

Testing Recommendations

• A tuberculin skin test (TST) or interferon-gamma release assay (IGRA) should be performed to diagnose latent TB infection 1.
• A chest radiograph should be obtained to evaluate for signs of active TB or other pulmonary diseases 1.
• If sarcoidosis is suspected, further testing may include pulmonary function tests, high-resolution computed tomography (HRCT) scans, and biopsy of affected tissues 1.

Clinical Implications

• Patients with latent TB infection should be treated with a complete therapeutic regimen for latent TB to prevent progression to active disease 1.
• Patients with sarcoidosis may require treatment with corticosteroids or other immunosuppressive agents to manage symptoms and prevent disease progression 1.

From the Research

Diagnosis of Granulomatous Diseases

The presence of a calcified granuloma and calcified lymph nodes in a patient suggests prior granulomatous disease, which can be indicative of either tuberculosis (TB) or sarcoidosis.

• The study by 2 found that the pattern and distribution of calcified mediastinal lymph nodes on CT scans can help differentiate between TB and sarcoidosis.
• The mean short axis diameter of calcified nodes was significantly larger in sarcoidosis patients, and a focal pattern of calcification was more common in sarcoidosis, while complete calcification was more common in TB.

Differential Diagnosis

Differential diagnosis between TB and sarcoidosis can be challenging, especially when caseous necrosis is not seen and acid-fast staining is negative in the biopsy specimen of a patient with TB.

• The study by 3 highlights the importance of improved diagnostic tests, including genetic tests, to distinguish between these two diseases.
• The case report by 4 illustrates the difficulty in differentiating between TB and sarcoidosis, even with histopathological features and chest radiography.

Diagnostic Approach

A combined pathological-HRCT approach can be useful in assessing granulomatous lung diseases.

• The study by 5 proposes a topographical and morphological assessment of lesions to distinguish between different types of granulomatous diseases.
• The anatomical approach can be completed by assessing the morphological aspects of the lesions and associated signs, reflecting both the possible mechanisms of spread and the different types of pathological and/or reparative tissue related to the disease.

Testing for TB and Sarcoidosis

Given the patient's presentation, testing for both TB and sarcoidosis is warranted.

• The study by 6 highlights the importance of considering various aetiologies, including infection, reaction to haematological disease, or systemic sarcoidosis, when evaluating granulomatous diseases in patients with lymphoma.
• The presence of calcified granuloma and calcified lymph nodes, suggestive of prior granulomatous disease, should prompt further investigation, including CT scans, biopsy, and acid-fast staining, to determine the underlying cause.