## Core Concept
Civatte bodies, also known as colloid bodies or hyaline bodies, are apoptotic basal keratinocytes. They are a characteristic histopathological feature seen in certain skin conditions. These bodies are composed of condensed, eosinophilic cytoplasm and remnants of keratinocyte nuclei.

## Why the Correct Answer is Right
The correct answer, **Lichen planus**, is a chronic inflammatory mucocutaneous condition that affects the skin, mouth, and other areas. Civatte bodies are a hallmark of lichen planus, particularly in the context of interface dermatitis, where there is damage to the basal layer of the epidermis. The presence of Civatte bodies in lichen planus is associated with the degeneration of basal keratinocytes, which is a key feature of the disease's pathology.

## Why Each Wrong Option is Incorrect
* **Option A:** While Civatte bodies can be seen in various conditions, **Psoriasis** is not typically characterized by their presence. Psoriasis is more associated with parakeratosis, Munro's microabscesses, and Kogoj's spongiform pustules.
* **Option B:** **Eczema** or atopic dermatitis does not characteristically show Civatte bodies. Eczema is more associated with spongiosis (intercellular edema) and a mixed inflammatory infiltrate.
* **Option D:** **Pemphigus vulgaris** is an autoimmune disease characterized by intraepithelial blistering due to antibodies against desmogleins. While acantholysis (separation of keratinocytes) is a feature, Civatte bodies are not typically highlighted as a diagnostic criterion.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that Civatte bodies are not exclusive to lichen planus but are also seen in other interface dermatitides like **discoid lupus erythematosus** and **dermatomyositis**. However, their presence in a biopsy can strongly suggest lichen planus, especially in the appropriate clinical context.

## Correct Answer Line
**Correct Answer: C. Lichen planus.**