**Question:** Call exner bodies are seen in:

**Core Concept:**
Exner bodies are small, round, pale, and eosinophilic inclusion bodies present in the central region of the primary sensory ganglion cells, specifically in the dorsal root ganglia (DRG) of the spinal cord. They are formed due to the accumulation of lipofuscin-like pigments called lipofuscin granules. These bodies are part of the normal aging process and are also seen in certain pathological conditions, such as Alzheimer's disease and Parkinson's disease.

**Why the Correct Answer is Right:**
Exner bodies are predominantly found in the dorsal root ganglia (DRG) of the spinal cord. This is because DRG neurons are the primary sensory neurons responsible for transmitting sensory information from the peripheral nerves to the central nervous system. As these neurons age, lipofuscin-like pigments accumulate within the cell bodies, resulting in the formation of Exner bodies.

**Why Each Wrong Option is Incorrect:**
A. This option is incorrect because Exner bodies are not found in the central nervous system (CNS). The CNS refers to the brain and spinal cord, while Exner bodies are found in the DRG, which is a part of the peripheral nervous system (PNS).

B. This option is incorrect because Exner bodies are not specific to Alzheimer's disease. Although they may be found in Alzheimer's, they are also seen in other conditions, including Parkinson's disease, as mentioned earlier. Exner bodies are a normal part of the aging process and not a specific marker for any disease.

C. This option is incorrect because Exner bodies are not exclusively present in the peripheral nerves. While they are primarily found in DRG, they can also be found in other parts of the PNS, including the ganglia of the autonomic nervous system and the sympathetic ganglia. However, the correct answer is still A, as Exner bodies are not found in the CNS.

D. This option is incorrect because Exner bodies are not unique to Parkinson's disease. As mentioned, they are a normal part of the aging process and can also be seen in other conditions, such as Alzheimer's disease.

**Clinical Pearl:**
Exner bodies are a common histopathological finding in sensory neurons of the dorsal root ganglia and are a part of the normal aging process. They are typically seen in various neurodegenerative disorders, including Alzheimer's disease and Parkinson's disease, but also in other conditions like multiple system atrophy and progressive supranuclear palsy. However, the correct answer is A, as Exner bodies are not found in the CNS.