Diagnosis

• Diagnosis of sarcoidosis is firm when chest radiographic evidence is accompanied by compatible clinical features and noncaseating granulomas on biopsy, with all other causes of granulomas ruled out.

• Biopsy is indicated for all patients presumed to have sarcoidosis, except those with Löfgren’s syndrome.

• Pathologists can identify granulomas, but the diagnosis should not be based on pathological findings alone.

• A response to corticosteroid therapy does not establish the diagnosis of sarcoidosis.

• Measurement of the serum angiotensin-converting–enzyme level is an insensitive and nonspecific diagnostic test and a poor therapeutic guide.

• For patients without apparent lung involvement, FDG PET is useful in identifying sites for diagnostic biopsy.

• FDG PET and MRI with gadolinium detect cardiac and neurologic involvement. (Caution in the use of gadolinium is needed, given the possibility that nephrogenic fibrosing sclerosis may develop in patients with chronic kidney disease.)

• CT imaging is unnecessary for most patients with sarcoidosis. CT is indicated when the chest radiograph is atypical for sarcoidosis or when hemoptysis occurs.

Clinical characteristics

• Constitutional symptoms such as fatigue may predominate.

• Cardiac sarcoidosis is much more common than reported previously and may cause loss of ventricular function and sudden death.

• Cardiac and neurologic sarcoidosis may occur without apparent disease activity in other organs.

• Chest radiographic patterns (stages 1, 2, and 3) do not reflect the chronology of the disease.

Treatment

• Most patients with sarcoidosis do not require therapy.

• There have been few well-controlled studies of the use of any therapeutic agent in patients with sarcoidosis — be skeptical of anecdotal reports.

• Treatment for pulmonary sarcoidosis is best guided by pulmonary-function studies.

• Deforming sarcoidal skin lesions are usually chronic and require prolonged therapy.

Abbreviations: FDG PET denotes 18F-fluorodeoxyglucose positron-emission tomography, MRI magnetic resonance imaging, and CT computed tomography.

References:

1. Iannuzzi MC, Rybicki BA, Teirstein AS. Sarcoidosis. N Engl J Med. 2007 Nov 22;357(21):2153-65. [Medline]