Acanthosis
Pronunciation: ak-an-THOH-sis
Diffuse epidermal hyperplasia characterised by thickening of the stratum spinosum (prickle-cell layer) of the skin.
Full Definition
Acanthosis refers to the abnormal thickening of the stratum spinosum, the middle layer of the epidermis, due to an increase in keratinocyte proliferation. It is a histopathological finding rather than a clinical diagnosis in its own right, and is commonly described in biopsy reports for conditions such as psoriasis and seborrhoeic keratosis. Editors must distinguish the root term from the compound 'acanthosis nigricans,' which is a distinct clinical entity associated with insulin resistance. The term derives from the Greek 'akantha' (thorn), referring to the spiny appearance of cells in this layer. When editing pathology reports, the term should not be hyphenated or capitalised mid-sentence.
Usage
Usage note: Do not conflate with 'acanthosis nigricans,' which is a specific hyperpigmented skin condition. When appearing as a standalone histological descriptor, lowercase mid-sentence.
In Context
- "The histological section demonstrated marked acanthosis with elongation of the rete ridges, consistent with chronic plaque psoriasis." — Dermatopathology biopsy report
- "Acanthosis was noted alongside hyperkeratosis in the punch biopsy specimen submitted for analysis." — Clinical laboratory report