Histologic Changes

Asteroid bodies (ABs): ABs are striking cytoplasmic inclusions in giant cells of granulomas of many types including those of sarcoidosis, tuberculosis, leprosy, fungal infections, schistosomiasis, and lipoid and foreign body types. They vary in size from 5 to 30 µm and have up to 30 rays forming a star-like, spider, or umbrella pattern. The surrounding cytoplasm is vacuolated [1]. There is controversy about their composition. Some believe the radiating spokes are composed of cytoplasmic filaments [2], and others believe they are composed of microtubular components [3,4]. In any case, the pathophysiologic changes that produce the ABs are unknown.

Each of the two multinucleated giant cells shown here has an asteroid body with surrounding vacuoles in the cytoplasm. The basophilic body in the giant cell to the left may be an early, small Schaumann body. No crystalline component was associated with it. As with Schaumann bodies, the ABs are found in the non-necrotizing granulomas and not in necrotic areas.

Ultrastructural findings: The fibrillar material of the spokes radiates from a granular center. The vacuoles between the spokes contain lamellated, lipoidal, myelin figures that may be related to the formation of Schaumann bodies [2].

References:

1. Rosen Y, Vuletin J, Pertschuk L, Silverstein E. Sarcoidosis. From the pathologist's vantage point. Pathol Annu 1979 Part 1; 14:405-439.

2. Kirkpatrick C, Curry A, Bisset D. Light- and electron-microscopic studies on multinucleated giant cells in sarcoid granuloma: new aspects of asteroid and Schaumann bodies. Ultrastructural Pathol 1988; 12:581-597.

3. Cain H, Kraus B. Asteroid bodies: derivatives of the cytosphere. An electron microscopic contribution to the pathology of the cytocentre. Virchows Arch B Cell Path 1977; 26:119-132.

4. Gadde P, Moscovic E. Asteroid bodies: products of unusual microtubule dynamics in monocyte-derived giant cells. An immunohistochemical study. Histol & Histopathol 1994; 9:633-642.

Clinical summary Discussion

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