## **Core Concept**
Multiple myeloma is a type of hematologic malignancy characterized by the proliferation of malignant plasma cells in the bone marrow. The disease is associated with various clinical features, including bone pain, anemia, renal failure, and hypercalcemia, due to the overproduction of monoclonal immunoglobulins or their components.

## **Why the Correct Answer is Right**
The correct answer, , is the least common feature among the options provided for multiple myeloma. Typically, multiple myeloma presents with anemia, bone lesions (lytic lesions), renal impairment, and hypercalcemia. Among these, certain features like lytic bone lesions, anemia, and renal failure are very common.

## **Why Each Wrong Option is Incorrect**
- **Option A:** is a common feature of multiple myeloma.
- **Option B:** is also frequently observed.
- **Option C:** represents another typical presentation.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl in multiple myeloma is the CRAB criteria, which stands for Calcium elevation, Renal failure, Anemia, and Bone lesions. These are critical for the diagnosis of multiple myeloma. Among these, while all are significant, certain features like bone lesions and anemia are particularly prevalent.

## **Correct Answer:** .