Histopathological examination of a plaque of psoriasis shows small aggregates of cells within the stratum corneum overlying parakeratotic areas. These aggregates, called Munro microabscesses, are composed of:

• A Eosinophils
• B Lymphocytes
• C Histiocytes
• D Neutrophils ✓

Explanation

Munro microabscesses are collections of neutrophils trapped within the stratum corneum, a direct consequence of the neutrophil chemokines (IL-8) produced by activated keratinocytes in the IL-23/Th17 axis. They differ from the spongiform pustules of Kogoj, which are neutrophil aggregates within the upper spinous layer forming sponge-like spaces. Eosinophils suggest a blistering or drug reaction, lymphocytes dominate lichenoid infiltrates, and histiocytes characterize granulomatous disease.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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