Endometrial adenocarcinoma with squamous cell differentiation

Area of Science:

• Gynecologic Pathology
• Oncology

Background:

• Endometrial carcinoma encompasses subtypes with squamous cell differentiation, historically termed adenoacanthoma and adenosquamous carcinoma.
• These distinct classifications may impact prognostic assessment and treatment strategies.

Purpose of the Study:

• To review and analyze cases of endometrial carcinoma with squamous cell differentiation diagnosed in Norway between 1970 and 1978.
• To compare the clinicopathologic features and survival rates of adenoacanthoma and adenosquamous carcinoma.
• To recommend standardized terminology for endometrial adenocarcinoma with squamous cell differentiation.

Main Methods:

• Histopathologic review of 1985 endometrial carcinoma cases.
• Identification and classification of 255 cases with squamous cell differentiation (181 adenoacanthoma, 74 adenosquamous carcinoma).
• Analysis of patient demographics, treatment (including hysterectomy), and survival data, stratified by tumor grade and myometrial infiltration.

Main Results:

• Adenosquamous carcinoma patients were older (mean age 62.8 years) than adenoacanthoma patients (mean age 57.7 years).
• Overall 5- and 10-year survival rates were 83.5% and 71.8%. Adenoacanthoma showed higher survival rates (91.2% 5-year, 79.6% 10-year) than adenosquamous carcinoma (64.9% 5-year, 52.7% 10-year).
• When hysterectomy was performed and stratified by grade and myometrial infiltration, no significant survival difference existed between adenoacanthoma and adenosquamous carcinoma. Myometrial infiltration was the most critical prognostic factor in surgically treated patients.

Conclusions:

• The distinct survival rates observed between adenoacanthoma and adenosquamous carcinoma diminish when accounting for treatment and histopathologic factors.
• Myometrial infiltration depth is a crucial prognostic indicator in surgically managed endometrial carcinoma.
• A unified term, "adenocarcinoma with squamous cell differentiation," is proposed to replace adenoacanthoma and adenosquamous carcinoma for improved diagnostic clarity and consistency.