**Core Concept**
Russel bodies are characteristic pathological features found in certain types of cells, particularly those involved in the production of immunoglobulins. They are composed of aggregated immunoglobulin light chains that accumulate within the endoplasmic reticulum of plasma cells. This phenomenon is often seen in conditions such as multiple myeloma and Waldenström's macroglobulinemia.

**Why the Correct Answer is Right**
Russel bodies form due to the accumulation of immunoglobulin light chains that are misfolded or not properly processed in the endoplasmic reticulum. This leads to the formation of insoluble aggregates that cannot be secreted out of the cell. The presence of Russel bodies is a hallmark of plasma cell dyscrasias, where there is an abnormal proliferation of plasma cells. The endoplasmic reticulum is responsible for the synthesis and folding of immunoglobulins, and the accumulation of misfolded proteins leads to the formation of Russel bodies.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely to be incorrect as it does not accurately describe the composition or formation of Russel bodies.
**Option B:** This option may be related to a different pathological feature, such as amyloid deposits, which are composed of fibrillar proteins rather than aggregated immunoglobulin light chains.
**Option C:** This option may be incorrect as it does not accurately describe the cellular location of Russel bodies, which are found in the endoplasmic reticulum of plasma cells.

**Clinical Pearl / High-Yield Fact**
The presence of Russel bodies is a key diagnostic feature of plasma cell dyscrasias, and their identification can be crucial in the diagnosis of conditions such as multiple myeloma and Waldenström's macroglobulinemia.

**Correct Answer: C.**