Squamous cell carcinoma

Topic Completed: 1 August 2011

Minor changes: 13 August 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed search: squamous cell [title] carcinoma uterus

Mohamed Mokhtar Desouki, M.D., Ph.D.
Page views in 2019: 2,427
Page views in 2020 to date: 2,102
Cite this page: Desouki M. Squamous cell carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/uterusscc.html. Accessed September 26th, 2020.
Definition / general
  • Primary uterine squamous cell carcinoma is rare, and associated with pyometra
  • Rare tumors are considered verrucous carcinoma if have deep pushing border
  • Primary endometrial squamous cell carcinoma is uncommon, accounting for 0.1% to 0.5% of all uterine cancers; most cases are extensions of cervical primary
  • Coexisting primary adenocarcinoma of endometrium helps establish that the squamous component is of endometrial origin
  • Predisposing factors include: chronic pyometra (present in 30% of cases), cervical stenosis, uterine prolapse or inversion, endometrial squamous metaplasia, history of pelvic radiation
Clinical features
  • Most often found in white nonobese women age 67+ years
  • Presents with vaginal bleeding in 69% of cases
  • 36% of woman are nulliparous
  • Not caused by estrogen, not associated with HPV
Prognostic factors
  • Lymphovascular and myometrial invasion are poor prognostic factors
  • Survival is 70% - 80% in stage I tumors, but only 20% - 25% with stage III tumors
  • Surgery with postsurgical radiation or chemotherapy
Gross description
  • Resembles endometrioid carcinomas on gross examination, but occasionally may be white and sometimes have a condylomatous appearance
Microscopic (histologic) description
  • Criteria for diagnosis include:
    • (1) no coexisting adenocarcinoma,
    • (2) no continuity between tumor and cervical squamous epithelium, and
    • (3) no invasive cervical squamous cell carcinoma
  • Often prominent keratinization, as well as areas which appear benign
  • Some tumors have prominent spindle cell growth pattern suggesting a diagnosis of sarcomatoid squamous cell carcinoma
  • Papillary squamous cell carcinoma is a variant that consists of papillary structures with thin, fibrovascular cores covered by several layers of squamous epithelium with large amounts of cytoplasm and pleomorphic and hyperchromatic nuclei
Microscopic (histologic) images

AFIP images

Squamous cell carcinoma:

No glandular component;no involvement of the cervix

Tumor cells have clear cytoplasm and might be mistaken
for clear cell adenocarcinoma, but keratinization and other
evidence of squamous differentiation were present elsewhere

Endometrioid adenocarcinoma with squamous differentiation:

Well differentiated adenocarcinoma

Several morules appear in this adenocarcinoma

Morule surrounded
by malignant but
well differentiated

Another morule with central necrosis

Tumor may be designated as adenosquamous carcinoma

Adenosquamous carcinoma

Shows mostly the
squamous component
except for a single
malignant gland

Squamous elements are cytologically malignant

Cytology images

AFIP images

Adenocarcinoma with squamous differentiation (endometrial aspirate):
the clumped tumor cells toward the center of the illustration represent
adenocarcinoma, but the two spindled cells with an eosinophilic cyto-
plasm at the upper left indicate a squamous component

Positive stains
Negative stains
Differential diagnosis
Back to top
Image 01 Image 02