Prostate gland & seminal vesicles
Benign mimickers of carcinoma
Squamous metaplasia
Author: Andres Matoso, M.D.
Topic Completed: 1 January 2016
Minor changes: 4 September 2020
Copyright: 2003-2020, PathologyOutlines.com, Inc.
PubMed Search: Squamous metaplasia [title] prostate
Table of Contents
Definition / general | Essential features | Epidemiology | Pathophysiology | Etiology | Clinical features | Microscopic (histologic) description | Positive stains | Negative stains | Differential diagnosis | Additional referencesCite this page: Matoso A. Squamous metaplasia. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/prostatesquamousmet.html. Accessed January 22nd, 2021.
Definition / general
- Squamous metaplasia is usually an incidental finding in the setting of infarction in the nodules of benign prostatic hyperplasia or secondary to treatment (hormonal therapy and radiation)
Essential features
- Usually incidental finding in the setting of inflammation, acute infarction of benign prostatic hyperplasia, or secondary to hormone / radiation therapy, or following prostatic artery embolization therapy for benign prostatic hyperplasia
- Can present with cytologic atypia that is reactive to the underlying process
- The key to avoid misinterpretation as cancer is to identify the underlying cause: i.e, adjacent hemorrhage or obvious necrosis indicating infarction, clinical history of hormone therapy or radiation
Epidemiology
- It is more common to see in TURP specimens with infarct of nodules of benign prostatic hyperplasia
Pathophysiology
- It is a reactive change of the prostatic epithelium
Etiology
- Ischemia, hormone therapy, radiotherapy, inflammation
Clinical features
- Squamous metaplasia of the prostate is an incidental histologic finding without any clinical manifestations
- No treatment is required
Microscopic (histologic) description
- Nests of squamous epithelium whose cells have eosinophilic cytoplasm and focal keratinization
- Mitoses can be seen but should not be frequent
Positive stains
Negative stains
Differential diagnosis
- Main differential diagnosis is with squamous cell carcinoma and urothelial carcinoma
- The differential diagnosis is based in the degree of cytologic atypia and the presence of stromal invasion
Additional references
