Sarcoidosis

Sarcoidosis is non-necrotizing granulomatous disease of unknown etiology. It classically associated with (pulmonary) hilar lymphadenopathy. It may be found in almost any organ, e.g. heart, appendix.

General

• Diagnosis of exclusion - infection must be excluded.
• Radiologic differential diagnosis includes carcinomatosis.

Microscopic

Features:

• Granulomata, well-formed, non-necrotizing.
  • Negative for microorganisms with special stains (PAS-D, GMS, AFB).
• Usu. minimal (lymphoid) inflammation; sarcoid granulomas are known as "naked granulomas".
• In lung: interstitial location.

Images

• 

  Sarcoidosis - lung. (WC)

• 

  Granulomata in sarcoidosis with asteroid bodies. (WC)

www:

• Sarcoidosis - several images (upmc.edu).
• Neurosarcoidosis - several images (upmc.edu).

Stains

• ZN -ve.
• PASD -ve.
• GMS -ve.

Note:

• Done to r/o infection.

See also

• Medical lung diseases.
• Cardiac sarcoidosis.