Russell bodies are seen in
**Core Concept**
Russell bodies are abnormal, eosinophilic inclusions found in the cytoplasm of certain cells, particularly plasma cells. They are composed of immunoglobulin light chains and are often associated with abnormal protein folding and degradation.
**Why the Correct Answer is Right**
Russell bodies are typically seen in plasma cells undergoing heavy chain disease, a condition characterized by the accumulation of abnormal immunoglobulin heavy chains. This accumulation leads to the formation of Russell bodies, which can be observed under the microscope. The presence of Russell bodies is a hallmark of this disease and can be used for diagnostic purposes.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as Russell bodies are not typically associated with acute myeloid leukemia.
**Option B:** Incorrect, as Russell bodies are not a characteristic feature of chronic lymphocytic leukemia.
**Option C:** Incorrect, as Russell bodies are not seen in normal plasma cells or in conditions such as multiple myeloma.
**Clinical Pearl / High-Yield Fact**
Russell bodies are a classic example of abnormal protein aggregation, which can lead to cellular dysfunction and disease. This phenomenon is also seen in other conditions such as Alzheimer's disease and Parkinson's disease.
**Correct Answer:** D. Plasma cells in heavy chain disease.