Asteroid bodies are seen in-
**Core Concept**
Asteroid bodies are a type of inclusion body found in the cytoplasm of certain lymphocytes, particularly in conditions involving autoimmune diseases or viral infections. They are characterized by a central, eosinophilic, and usually rounded mass surrounded by a halo, resembling an asteroid.
**Why the Correct Answer is Right**
The formation of asteroid bodies is associated with the presence of immune complexes and the activation of the complement system, leading to the deposition of C3b and C4b on the surface of lymphocytes. This results in the aggregation of immune complexes and the subsequent formation of the characteristic central mass surrounded by a halo. Asteroid bodies are often seen in conditions such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and infectious mononucleosis.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because asteroid bodies are not typically seen in conditions involving direct viral infections, such as herpes simplex virus or varicella-zoster virus.
**Option B:** Incorrect because while lymphocytosis can be a feature of SLE, it is not the hallmark or distinctive feature of the condition.
**Option C:** Incorrect because while immune complexes can be seen in conditions such as SLE, the presence of asteroid bodies is more specific for certain autoimmune diseases.
**Clinical Pearl / High-Yield Fact**
Asteroid bodies can be a distinctive feature of SLE, particularly in patients with a history of renal involvement or high-titer anti-dsDNA antibodies. They can also be seen in other autoimmune conditions, such as rheumatoid arthritis and mixed connective tissue disease.
**Correct Answer: C. Rheumatoid Arthritis.**