Ectopic decidua and metastatic squamous carcinoma: presentation in a single pelvic lymph node

Area of Science:

• Gynecologic Pathology
• Surgical Pathology
• Oncologic Diagnosis

Background:

• Ectopic decidua in pelvic lymph nodes can mimic metastatic squamous carcinoma of the cervix.
• Accurate differentiation is crucial for staging and treatment of cervical cancer.

Purpose of the Study:

• To identify and describe the distinct morphological features differentiating decidua from metastatic squamous carcinoma in pelvic lymph nodes.
• To provide diagnostic criteria for challenging cases.

Main Methods:

• Light microscopy examination of a pelvic lymph node containing both decidualized endometriosis and metastatic squamous cell carcinoma.
• Comparative analysis of morphological characteristics of the two entities.

Main Results:

• Decidua and squamous cell carcinoma share light microscopic similarities, complicating diagnosis.
• Key distinguishing features of squamous carcinoma include cohesive cell nests, nuclear hyperchromasia, and cellular pleomorphism, especially when overt squamous differentiation is absent.

Conclusions:

• Morphological assessment is vital for distinguishing decidua from metastatic cervical squamous cell carcinoma in lymph nodes.
• Specific features like cellular cohesion, nuclear atypia, and pleomorphism aid in accurate diagnosis.