Parakeratosis
Pronunciation: par-ah-ker-ah-TOH-sis
A histopathological finding characterised by the retention of nuclei in cells of the stratum corneum, indicating abnormal keratinisation.
Full Definition
Parakeratosis is a microscopic feature reported in dermatopathology in which corneocytes of the stratum corneum retain their nuclei, reflecting disordered or accelerated epidermal differentiation. It is a hallmark of psoriasis but also appears in many other inflammatory and neoplastic skin conditions, including seborrhoeic dermatitis, actinic keratosis, and superficial fungal infections. Editors working on histopathology reports must recognize parakeratosis as a process-level descriptor, not a diagnosis. It is distinct from hyperkeratosis (thickening of the stratum corneum with normal, anucleate cells) and should not be used as a synonym for it.
Usage
Usage note: Used exclusively in a histopathological context. Distinguish from 'hyperkeratosis' (thickening) and 'orthokeratosis' (normal, anucleate keratinisation). The antonym is 'orthokeratosis'.
In Context
- "The biopsy showed confluent parakeratosis, hypogranulosis, and dilated capillaries in the papillary dermis, supporting a diagnosis of psoriasis." — Dermatopathology report
- "The author confused 'parakeratosis' with 'hyperkeratosis'; the editor inserted a query explaining the histological distinction." — Manuscript query note