Sentinel lymph node biopsy in rats. Comparison between paraffin and frozen section analysis

Area of Science:

• Veterinary Pathology
• Surgical Pathology
• Animal Models

Background:

• Lymph node metastasis is a critical prognostic indicator in cancer.
• Accurate pathological assessment of lymph nodes is essential for staging and treatment planning.
• Novel methods for simulating and evaluating metastasis in animal models are needed.

Purpose of the Study:

• To establish an animal model of lymph node metastasis using activated carbon injection.
• To evaluate the efficacy of frozen section analysis in detecting activated carbon in lymph nodes.
• To compare frozen section analysis with paraffin-embedded histopathology for metastasis assessment.

Main Methods:

• Thirty-two female rats received bilateral hind leg injections of activated carbon.
• Lymph nodes were harvested at 1 day and 21 days post-injection.
• Half of each lymph node underwent frozen section analysis, the other half was processed for paraffin histology.

Main Results:

• Activated carbon was visualized in all examined lymph nodes.
• A trend towards increased carbon spread over 21 days was observed, but it lacked statistical significance.
• Carbon staining intensity remained consistent over the 21-day period.

Conclusions:

• Activated carbon successfully marked lymph nodes in the animal model.
• No concordance was found between frozen section analysis and paraffin histopathology for pathological assessment.
• Further research is needed to refine methods for evaluating lymph node metastasis in animal models.