When the lymphatic system is unhealthy, it does not adequately transport and drain the lymph fluid in the skin of the thighs. The lymph fluid that remains in the skin leads to swelling, otherwise known as lymphedema. The term "secondary" denotes that the lymphedema has a cause, such as lymph node removal, an operation, injury, cancer treatments or parasites.
Lymph Node Removal for Biopsies or Testing
The removal of any number of inguinal lymph nodes may cause secondary lymphedema in the thighs. The lymph fluid in the lower extremity, from toes to thigh, drains in the inguinal lymph nodes. These are the lymph nodes located within the groin area.
Despite having fewer lymph nodes, a patient produces the same amount of daily lymph fluid in her thighs. Thus, the lymphatic system has to handle the same amount of lymph load with a less efficient and understaffed draining department. The lymph load that remains in the skin causes secondary lymphedema in the thighs.
Operations
Hip, knee, ankle replacements and other lower-extremity orthopedic operations may cause secondary lymphedema in the thighs. During an operation, a patient runs the risk of having her lymphatic system injured. Leg swelling is natural after a surgery; however, it may or may not be lymphedema.
After a surgery, a patient should monitor the swelling in his legs and have a vascular or lymphatic specialist examine him to help him differentiate between regular swelling and lymphedema.
Surgical operations within the abdominal area, such as colon or uterine surgeries, may also cause lymphedema in the thighs if there is damage to the lymphatic system.
Injury
Injuries to the lower extremities or groin area may cause secondary lymphedema in the thighs. Deep lacerations, second to third degree burns, broken bones, or other sorts of injuries may hurt the lymphatic system, thus decreasing its efficiency in draining lymph fluid and preventing swelling.
Infectious bug bites or infections may also cause secondary lymphedema in the thighs if there is any damage to the lymphatic system.
Filariasis
In developing countries, filariasis is a common cause of secondary lymphedema in the thighs. Filariasis is a parasitic nematode or worm that attacks lymph nodes in the human body. Attacked lymph nodes serve as homes to the parasites. These occupied lymph nodes function poorly in lymph fluid drainage.
Cancer Treatments
Having radiation treatments for cancer may inadvertently harm lymph vessels or lymph nodes. Other cancer treatments, such as the removal of the entire uterus from a female patient as a treatment for uterine cancer, may lead to secondary lymphedema in the thighs if lymph nodes were also removed or destroyed in the process.
