Differentiating Sarcoidosis from Tuberculosis

Clinical Features

Löfgren's syndrome, characterized by bilateral hilar adenopathy with erythema nodosum and/or periarticular arthritis, is highly probable for sarcoidosis, according to the American Thoracic Society 1
Lupus pernio, presenting as chronic violaceous skin lesions on the nose, cheeks, and ears, is highly specific for sarcoidosis, as recommended by the American College of Chest Physicians 1
Bilateral uveitis and optic neuritis strongly suggest sarcoidosis, with a high degree of evidence from the American Academy of Ophthalmology 1
Symmetrical parotid gland enlargement and lacrimal gland swelling favor sarcoidosis, based on guidelines from the American College of Rheumatology 1
Hypercalcemia or hypercalciuria with abnormal vitamin D metabolism is highly probable for sarcoidosis, with a moderate level of evidence from the Endocrine Society 1
Elevated ACE levels (>50% above upper limit of normal) support sarcoidosis, though this is not specific, according to the American College of Physicians 1
BAL lymphocytosis with elevated CD4:CD8 ratio favors sarcoidosis, with a high degree of evidence from the American Thoracic Society 1, 2

Bilateral, symmetrical hilar and mediastinal lymphadenopathy is the hallmark of sarcoidosis, with a high degree of evidence from the American College of Radiology 1, 2
Perilymphatic nodular distribution on chest CT is highly characteristic of sarcoidosis, based on guidelines from the Fleischner Society 1, 2
Upper lobe predominant or diffuse infiltrates with symmetrical distribution are common in sarcoidosis, with a moderate level of evidence from the American Thoracic Society 1

Compact, tightly formed, non-caseating granulomas with large epithelioid histiocytes and multinucleated giant cells are strongly suggestive of sarcoidosis, with a high degree of evidence from the American Society for Clinical Pathology 3, 4
Perilymphatic distribution and sparse surrounding lymphocytic infiltrate are characteristic of sarcoidosis, based on guidelines from the College of American Pathologists 3
Negative microorganism stains and cultures are essential for diagnosing sarcoidosis, with a high degree of evidence from the American Thoracic Society 3, 2

Evaluate for highly specific sarcoidosis features, such as Löfgren's syndrome, lupus pernio, and bilateral uveitis, as recommended by the American College of Chest Physicians 1
Assess TB risk factors, including endemic area, exposure history, and constitutional symptoms, based on guidelines from the Centers for Disease Control and Prevention 1
Perform initial imaging, including chest radiograph and CT, to assess lymphadenopathy pattern, with a moderate level of evidence from the American College of Radiology 1, 2
Obtain tissue biopsy showing granulomatous inflammation and perform acid-fast bacilli staining and mycobacterial cultures, with a high degree of evidence from the American Thoracic Society 2, 3