**Micro-Munro Abscess**

**Core Concept**
Micro-Munro abscesses are small collections of neutrophils within the epidermis, often associated with psoriasis. They represent a key pathologic feature of the disease, contributing to the thickening of the epidermis and the development of psoriatic plaques.

**Why the Correct Answer is Right**
Micro-Munro abscesses are characterized by the presence of neutrophils in the epidermis, which is a hallmark of psoriasis. This occurs due to the abnormal expression of adhesion molecules on the surface of keratinocytes and endothelial cells, leading to the recruitment of neutrophils into the epidermis. The presence of neutrophils in the epidermis is a result of the breakdown of the normal epidermal-dermal junction, allowing neutrophils to migrate from the dermis into the epidermis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because micro-Munro abscesses are not a feature of seborrheic dermatitis, which is a different skin condition characterized by a distinct clinical and histopathological appearance.
**Option B:** This option is incorrect because micro-Munro abscesses are not typically associated with eczema, although eczema can also involve neutrophilic infiltration in some cases.
**Option C:** This option is incorrect because micro-Munro abscesses are not a feature of acne vulgaris, which is characterized by comedones, inflammation, and the presence of Propionibacterium acnes.

**Clinical Pearl / High-Yield Fact**
Micro-Munro abscesses are a key diagnostic feature of psoriasis, and their presence can be used to differentiate psoriasis from other skin conditions. Remember that the presence of neutrophils in the epidermis is a hallmark of psoriasis, and this can be a useful clue in the diagnosis of this condition.

**Correct Answer:** None of the above.