Mediastinal lymph node distribution, size and number: definitions based on an anatomical study.

Area of Science:

• Anatomy
• Medical Imaging
• Surgical Pathology

Background:

• Accurate anatomical knowledge of mediastinal lymph nodes is crucial for staging and treatment of thoracic malignancies.
• Existing lymph node maps lack detailed size and distribution data, hindering precise clinical application.

Purpose of the Study:

• To establish a comprehensive reference map of mediastinal lymph nodes.
• To analyze the size, number, and distribution of lymph nodes across different anatomical stations.
• To provide data for improved diagnostic and therapeutic strategies in thoracic oncology.

Main Methods:

• Bilateral mediastinal dissection was performed on 50 cadavers (38 male, 12 female, 39 Caucasian).
• Lymph nodes were resected, isolated, and analyzed using radiographic imaging.
• Measurements included area and transverse diameters; station presence and node counts were recorded.

Main Results:

• A total of 1742 lymph nodes were dissected from 485 chains.
• Stations 1, 2R, 4R, 5, and 7 were consistently present (>90%); stations 4R and 7 were always present.
• Stations 2R, 4R, and 7 exhibited the highest number and largest size of mediastinal lymph nodes.

Conclusions:

• A feasible reference map for mediastinal lymph node size and distribution was created.
• No significant variations in lymph node distribution, number, or size were observed based on age, gender, race, weight, or height.