Introduction: Lymphedema commonly occurs secondarily to cancer interventions, including the surgical removal of lymph nodes (LN). Previous findings from authors such as, Földi, Standring, Moore, Hsu, and Itkin, indicate there are 500-800 LNs in the lymphatic system of the body, with 41-154 in the pelvic region. Deciding how many LN to remove and predicting possible severity of damage can become problematic when the range of LN in an area can vary by 30 LNs

Aim: The purpose of this study was to investigate more precise ranges of pelvic LNs within cadaver samples to provide reference for future surgical procedures and treatment of lymphedema.

Method: Quantification of LNs for number occurred on cadavers simultaneous with Doctor of Osteopathic, Physical Therapy, and Physician Assistant students’ dissections. Demographics of the cadavers were 27 female, 16 male, 39 Caucasian, 3 African American, 1 Asian, with an age range of 42-102 and a mean of 70. Anatomical landmarks were referenced to identify and label the LNs. Cadavers (N=43) inspected for lumbar LNs and cadavers (N=86 sides) inspected for sacral, common, deep and superficial inguinal, and internal and external iliac LNs. Regions not meeting a set minimum due to previous medical interventions or overzealous students were removed from statistics.

Results: Quantitative analysis of the pelvic region LNs revealed a power analysis value of 0.733 with 43 cadaver sample size (unpaired LN regions) and a value of 0.954 with a 86 cadaver sample size (paired LN regions). Analysis of LNs in unpaired lumbar region revealed the true mean of the LNs lies between 20-28 [CI=95] while previous data shows LN quantity ranging from 20-50. The true mean of LNs in paired regions lies between [CI=95] from 6-10(numerical range 5-30) for the common iliac, 2-3(numerical range 2-3) for the sacral, 5-7(numerical range 4-18) for the internal iliac, 10-13(numerical range 5-25) for the external iliac, 2-4(numerical range 1-3) for the deep inguinal, and 9-12(numerical range 4-25) for the superficial inguinal.

Conclusions: Reduced ranges of LNs per region were found in every region except the common iliac and deep inguinal regions. The results from the study could be referenced by a surgeon to create a more precise management plan when deciding the number of LNs to remove for diagnosis and treatment of cancer. This can also aid lymphedema therapists in anticipating the level of risk for a patient post cancer interventions and expectant outcomes with actual lymphedema treatment.