Skin nonmelanocytic tumor
Premalignant / in situ
Squamous cell carcinoma in situ / Bowen disease
Author: Christopher S. Hale, M.D.
Last author update: 1 June 2012
Last staff update: 31 March 2023
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Carcinoma in situ [title] skin
Table of Contents
Definition / general | Case reports | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Hale CS. Squamous cell carcinoma in situ / Bowen disease. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumornonmelanocyticcisgeneral.html. Accessed April 26th, 2024.
Definition / general
- Usually on skin NOT exposed to sunlight, such as trunk
- Called erythroplasia (of Queyrat) if at glans penis, vulva, oral cavity
- Actinic keratosis with only a single layer of atypical keratinocytes may be invasive but Bowen disease seldom is
- Mucosal variants in glans penis (penile intraepithelial neoplasia or "PIN") and vulva (vulvar intraepithelial neoplasia or "VIN") are associated with more aggressive behavior
Case reports
- 36 year old man with pigmented Bowen disease (Ann Dermatol 2009;21:197)
- 69 year old woman with coexisting basaloid carcinoma of nipple (Breast J 2009;15:409)
- 78 year old man with multifocal persistent lesions of glans (J Dtsch Dermatol Ges 2006;4:559)
- Tumor of nipple (Hum Pathol 1994;25:1371)
- Tumor of nipple in young man with HIV (Clin Breast Cancer 2009;9:53)
Gross description
- Slightly raised, large scaly erythematous plaque with irregular border
- Usually single patch or verrucous growth
Microscopic (histologic) description
- By definition requires full thickness keratinocyte atypia, although may be surrounded by normal keratinocytes
- Architectural and cellular atypia, apoptotic cells, individual cell dyskeratosis
- Markedly altered maturation but usually still some surface keratinization and intercellular bridges present
- Marked nuclear atypia, including nuclear hyperchromasia and multinucleation
- Numerous mitotic figures, atypical mitotic figures
- Also cytoplasmic vacuoles; rarely pagetoid cells or ground glass cytoplasm
- May extend into eccrine sweat glands (not considered invasive disease)
- Variable melanin, variable lymphocytic infiltrate
- May have hemangiomatous vascular proliferation, amyloid globules, adnexal differentiation
Microscopic (histologic) images
Contributed by Amy Lynn, M.D., Andrey Bychkov, M.D., Ph.D. and Jijgee Munkhdelger, M.D., Ph.D.
Various images
Full thickness atypia
Hyperkeratosis and acanthosis
Pleomorphism, multinucleation
High power
Images hosted on other servers:
Various images
Differential diagnosis
- Actinic keratosis
- Arsenical keratosis
- Superficially invasive squamous cell carcinoma
