Disease directory
Keratoacanthoma
Published: September 18, 2026Updated: September 18, 2026
Important: Informational content intended for healthcare professionals. It does not replace clinical evaluation or establish a doctor-patient relationship.
Overview
- Definition and synonyms
- A well-differentiated, rapidly growing (weeks) cutaneous squamous epithelial tumor with a typically self-limiting course, exhibiting a keratin-filled «crater» morphology, but with the potential for local invasion and, rarely, metastasis. In clinical practice, it is now considered a low-grade, well-differentiated squamous cell carcinoma («keratoacanthoma-like squamous cell carcinoma»). Kwiek 2016 , Schwartz 2004
- Historical synonyms: crater epithelioma , molluscum sebaceum , keratoacanthoma-type SCC , “crateriform squamous proliferation”. Schwartz 2004
- History
- Clinically described as “ crateriform ulcer of the face ” by Hutchinson in 1889.
- The term “keratoacanthoma” became popular in the mid-20th century to highlight its rapid growth and potential regression. Nagarajan 2020
- Epidemiology
- A common but underreported tumor among keratinocytic tumors. Kwiek 2016
- Peak in adults >60 years ; exceptional in children.
- It predominates in light phototypes (I–III) and in photoexposed areas (face, back of hands, forearms).
- Slight male predominance in most series. Sánchez Yus 2000 , Watanabe 2015
- Increased incidence in immunocompromised patients (solid organ transplant, hematological) and in those treated with BRAF, EGFR, PD-1, or TGF-β inhibitors. Kwiek 2016 , Ambur 2022
- Codes ( always check local coding regulations)
- ICD-10-CM
- L85.8 – Other specified epidermal thickenings (used in many systems for solitary QA).
- D48.5 – Skin neoplasm of uncertain behavior (when biological uncertainty is emphasized).
- C44.x – Squamous cell carcinoma of the skin (when coded as keratoacanthoma type SCC).
- ICD-11
- 2C31.1 – Keratoacanthoma .
- ICD-10-CM
- Diagnostic checklist (quick)
- Essential clinic
- Adult patient (frequently >60 years old) with a rapidly growing nodule (weeks).
- Dome-shaped lesion with a central keratotic crater, usually in a sun-exposed area.
- Dermatoscopy with central keratin, white circles and hairpin vessels / hemorrhagic spots (if available).
- Minimum laboratory/cabinet
- No specific tests are required for the isolated lesion.
- Consider imaging (ultrasound/CT) if the tumor is large, deep, or close to critical structures.
- Biopsy
- Complete excision (preferred) or deep incisional excision that includes the rim and base of the crater.
- Sample fixed in 10% formalin, with anatomical identification and clear clinical suspicion.
- Histology / IHC key
- Symmetrical crater-like architecture with a thrust base.
- Mild-moderate atypia, low-moderate Ki-67 index, non-diffuse p53.
- Absence of deep infiltrative tongues, perineural invasion and/or marked atypia → Classical QA.
- If doubtful or “borderline” findings → label as QA type CEC and handle as CEC.
- Essential clinic
Doctors who treat Keratoacanthoma
Directory specialists related to Keratoacanthoma.
There are no specialists associated with this record yet
You can browse the full directory and filter by the condition you're interested in.
Go to directory