Penis and scrotum - Squamous hyperplasia

Home Chapter Home Jobs Conferences Fellowships Books

Penis and scrotum

Benign Tumors

Squamous hyperplasia

Editor: Antonio Cubilla, M.D. and Alcides Chaux, M.D. (See Reviewers page)

Revised: 20 May 2010, last major update February 2010

Definition

=========================================================================

● Benign thickening of squamous epithelium (more than 15 cell layers) without atypia

Sites

=========================================================================

● May affect any penile anatomical compartment

Clinical features

=========================================================================

● Most common epithelial change associated with keratinizing penile carcinoma

● Usually found adjacent to neoplastic changes (in situ or invasive carcinoma)

● Uncertain if reactive or precancerous (Anal Quant Cytol Histol 2007;29:185)

● Benign, but associated with squamous cell carcinoma, particularly verrucous and low grade papillary subtypes (Int J Surg Pathol 2004;12:351)

Gross description (Macroscopy)

=========================================================================

● Flat, smooth and slightly raised pearly white areas

Micro description (Histopathology)

=========================================================================

● Hyperkeratosis, acanthosis and hypergranulosis but normal maturation of squamous epithelium

● Minimal to no parakeratosis

● No cytological atypia, no koilocytosis

● May be adjacent to carcinoma or merge with adjacent low grade carcinoma

Morphological Patterns

● Flat: most common type, linear interface between epithelium and lamina propria

● Papillary: serrated appearance at low-power view, jagged interface with stroma

● Pseudoepitheliomatous: downward florid but superficial proliferation of regular squamous cell nests with peripheral palisading, often appearing detached, but with no keratinization, no stromal reaction, no desmoplasia, no extension beyond lamina propria

● Verrucous: marked acanthosis with hyperkeratosis, slight papillomatosis, linear interface with stroma

Micro images

=========================================================================

Squamous hyperplasia, as shown here, is characterized by acanthosis, absence of nuclear atypias and hyperkeratosis

Contributed by Dr. Alcides Chaux and Dr. Antonio Cubilla:

Squamous cell hyperplasia, flat: There is hyperkeratosis and acanthosis, but also normal maturation without atypia

Squamous cell hyperplasia, papillary: Pseudoepitheliomatous squamous cell

here is hyperkeratosis, papillomatosis hyperplasia: There is a downward proliferation

and acanthosis of mature, nonatypical squamous epithelium

forming nests with focal keratinization.

Differential Diagnosis

=========================================================================

● Penile intraepithelial neoplasia, differentiated type: cytological atypia, more frequent parakeratosis

● Pseudohyperplastic carcinoma: irregular nests, no peripheral palisading, evident stromal reaction, extension beyond lamina propria

● Squamous cell carcinoma with pseudohyperplastic features

● Verruciform carcinomas: cytological atypia, evidence of stromal invasion

● Verruciform xanthoma: lipid-laden histiocytes (foamy cells) in lamina propria

End of Penis and scrotum > Benign tumors > Squamous hyperplasia

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must also be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).