A renal biopsy from a 56 year old woman with progressive renal failure for the past 3 years shows glomerular and vascular deposition of pink amorphous material.It shows apple-green birefringence under polarized light after Congo red staining. These deposits are positive for lambda light chains. the person is most likely to suffer from ?
**Core Concept**
The underlying principle being tested is the identification of a specific type of amyloidosis based on the characteristics of the deposits found in the renal biopsy. **Amyloidosis** is a condition characterized by the deposition of insoluble abnormal proteins (amyloid) in various tissues of the body, leading to tissue damage and disease. The presence of **apple-green birefringence** under polarized light after **Congo red staining** is diagnostic for amyloidosis.
**Why the Correct Answer is Right**
The description provided points towards **AL amyloidosis**, also known as primary amyloidosis, which is associated with the deposition of light chain (LC) immunoglobulins. The fact that the deposits are positive for **lambda light chains** supports this diagnosis, as AL amyloidosis can involve either kappa or lambda light chains. This condition is often related to **multiple myeloma** or other **plasma cell dyscrasias**.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific details of option A, we cannot directly address why it is incorrect, but if it does not involve lambda light chains or is not associated with amyloidosis, it would be incorrect.
**Option B:** Similarly, without specifics, if this option does not align with the characteristics of AL amyloidosis or the clinical presentation, it would be an incorrect choice.
**Option C:** If this option suggests a different type of amyloidosis, such as AA amyloidosis (associated with chronic inflammation) or hereditary amyloidosis, it would not match the lambda light chain positive description provided.
**Option D:** Any option that does not involve amyloidosis or the specific immunoglobulin light chain deposition described would be incorrect.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **AL amyloidosis** is a condition that can lead to significant organ dysfunction, including renal failure, and its diagnosis often requires the identification of amyloid deposits in tissues and the characterization of the amyloid protein. The presence of **lambda or kappa light chains** in these deposits is crucial for distinguishing AL amyloidosis from other forms.
**Correct Answer:** D. AL amyloidosis.