POPLITEAL SWELLING

The key to recalling the causes of a popliteal swelling is anatomy. Each structure in the popliteal space may be involved by one or two conditions that cause a mass or swelling. In visualizing the anatomy, one encounters the skin, subcutaneous tissues, muscles, bursae, veins, arteries, lymphatics, nerves, and bones.

1. Skin. The skin may be involved by urticaria, sebaceous cysts, carbuncles, lipomas, hemangiomas, and various other skin masses.
2. Subcutaneous tissue. Lipomas, sarcomas, and cellulitis are the main lesions encountered.
3. Muscle. Contusions of the gastrocnemius and semimembranous muscles may cause a mass in the popliteal fossa.
4. Bursae. Popliteal cysts (Baker cysts) may result from filling of the bursa between the gastrocnemius and semimembranous muscles with a gelatinous or serous substance.
5. Veins. The veins may enlarge from a varicocele or thrombophlebitis.
6. Artery. An aneurysm of the popliteal artery may result from atherosclerosis or a gunshot wound. When there is a loud bruit over the artery and distention of the veins, an arteriovenous fistula should be considered.
7. Lymphatics. Enlarged popliteal nodes may result from infections in the distal portion of the extremity, tuberculous adenopathy, or metastatic malignancy.
8. Nerves. Traumatic neuromas or neurofibromas may involve the nerves here.
9. Bone. Exostosis arising from the epiphyseal cartilage of the femur is a well-defined tumor of children or young adults. Medullary giant cell tumors, fibrosarcomas of the periosteum, and osteomyelitis may present as a mass in this area also. Fractures and periosteal hematomas should present no problem in diagnosis.

Approach to the Diagnosis

Initial workup includes a CBC, sedimentation rate, and an x-ray of the knee. If these have negative findings, it may be wise to consult an orthopedic surgeon before any other tests are done. If a Baker cyst is suspected, aspiration will help make the diagnosis. Before doing this, it is wise to rule out a varicocele by watching for the disappearance of the mass on elevation of the leg. Ultrasonography can also assist in this differentiation. Ultrasonography will also be helpful in ruling out an aortic aneurysm. If there is joint swelling or other signs of joint involvement, an MRI should be performed. If the mass seems fixed to the bone, a bone scan or CT scan of the bone and joint is ordered.

Other Useful Tests

1. CBC
2. Sedimentation rate (abscess)
3. Tuberculin test
4. Arthritis profile (gout, lupus, rheumatoid arthritis)
5. Synovial fluid analysis (septic arthritis, rheumatoid arthritis, lupus)
6. Arthroscopy (torn meniscus)
7. Lymphangiogram (lymph node mass)
8. Exploratory surgery and biopsy
9. Arteriogram (Baker cyst, aneurysm)

Pictures

Book Source Details

• Book Title: Differential Diagnosis in Primary Care
• Author(s): R. Douglas Collins MD, FACP
• Year of Publication: 2007
• Copyright Details: Differential Diagnosis in Primary Care, Copyright © 2007 Lippincott Williams & Wilkins.

Other Book Chapters Related to Swelling symptoms

Read excerpts from these other book chapters related to Swelling symptoms:

Copyright Details: Differential Diagnosis in Primary Care, Copyright © 2008 Williams & Wilkins.

More About Causes of Swelling symptoms

• Back to symptom: Swelling symptoms: Introduction (review 3250 causes)
• Next Book Extract About Swelling symptoms: SWOLLEN GUMS AND GUM MASS (Differential Diagnosis in Primary Care)
• All Book Extracts: All Online Book Extracts for Swelling symptoms

More About This Book: Title: Differential Diagnosis in Primary Care Authors: R. Douglas Collins MD, FACP Publisher: Lippincott Williams & Wilkins Copyright: 2007 ISBN: 0-7817-6812-8

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• SWOLLEN GUMS AND GUM MASS (Differential Diagnosis in Primary Care)
• SWOLLEN TONGUE (Differential Diagnosis in Primary Care)
• Medications causing Swelling symptoms
• Videos relating to Swelling symptoms
• Drug interactions causing Swelling symptoms

Tools & Services:

• Bookmark this page
• Take a survey relating to Swelling symptoms
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

Common Health Mistakes

Symptom
Checker

Search Specialists by State and City