diagnosing lymphedema   

Diagnosing Lymphedema
Introduction
Approximately 90% of all lymphedema cases are diagnosed on the basis of a medical history and current symptoms. The remaining 10% of lymphedema cases require more complex diagnostic measures. [1]
The Family History
Primary lymphedema is considered when the patient has a family history of this condition. However even without a family history, primary lymphedema cannot be ruled out when there is swelling of unknown cause present in the legs.
The Medical History
Secondary lymphedema is considered when the patient’s medical history includes any events that place the patient at risk for lymphedema. See Are You at Risk for Lymphedema? Because of the delayed onset of secondary lymphedema, these risk factors are not necessarily of recent origin. See Delayed Onset of Lymphedema.
 
Swelling due to lymphedema  

The Physical Examination
Swelling is the most obvious indication of lymphedema; however, not all swelling is due to lymphedema!
Pitting edema is a diagnostic sign for stage 1 lymphedema. The test for pitting edema is to gently press a finger against the swollen tissue. Pitting edema is present if this leaves an indentation that soon disappears. (Pitting edema can also be a diagnostic sign of other conditions.)
In the later stages of lymphedema, when the tissues have become fibrotic and are no longer soft, pitting edema is no longer present as a diagnostic sign.
 
Testing for Stemmer's sign.  
Stemmer’s sign is a thickened skin fold at the base of the second toe or second finger. The presence of this sign is an early diagnostic indication of primary lymphedema. It develops later in secondary lymphedema. The absence of Stemmer’s sign does not rule out the possibility of lymphedema. 
To test for Stemmer’s sign, pinch the skin folds on the upper surface of the second toe or finger as shown here. When this skin cannot be lifted, this is considered to be a positive test result that could indicate the presence of lymphedema; however, a negative Stemmer's sign does not exclude lymphedema. [2]
Rule Outs 
Lymphedema is not the only condition that causes abnormal swelling of the tissues and it is important that the healthcare provider rule out these other conditions before reaching a diagnosis of lymphedema. A rule-out is the process of eliminating conditions that could possibly be causing the presenting symptoms.
Sudden swelling could be a sign of a blood clot. This is potentially serious and requires immediate attention.
Slowly progressive swelling, particularly of the legs, can be due to other conditions, such as lipedema or a heart condition, that impair the circulation.[3] See Chronic Venous Insufficiency and Lymphedema, Lipedema, Lymphedema, and Lipo-Lymphedema, Diabetes and Lymphedema and Obesity and Lymphedema.
Rapidly progressive and painful lymphedema-type swelling could be due to a fast-growing tumor that places pressure on lymph nodes and the nerves. This condition is known as malignant lymphedema; however it is the tumor, not the lymphedema, that is malignant.[4]
Imaging
Lymphoscintigraphy produces an image of the lymph flow and speed of uptake. When necessary, computerized tomography (CT), magnetic resonance imaging (MRI), and ultrasound techniques can be used to image tissues and structures that cannot be seen effectively with lymphoscintigraphy.[5] See Lymphoscintigraphy.
Who Diagnoses Lymphedema? 
Many times your primary caregiver makes the diagnosis of lymphedema. When the condition is related to cancer treatment, your oncologist may make the diagnosis. For more complex cases, you may want to consult a vascular surgeon. Help is available in finding a vascular surgeon by visiting the Society for Vascular Surgery web site and using their physician locator service. 
References
[1] Management of Childhood and Adolescent Lymphedema by J.F. Feldman. Lymph Link Vol 16:2, April-June 2004 p 1-26.
[2] A Primer on Lymphedema by D. G Kelly. Prentice Hall, 2002, page 48.
[3] Lymphedema National Cancer Institute (NCI) Comprehensive Cancer Information Database. October 2003.
[4] Living Well with Lymphedema by A. Ehrlich, A. Vinjé-Harrewijn PT, CLT, and E. McMahon PhD. Lymph Notes 2005, pages 19-26 and 85-96.
[5] The Third Circulation: Radionuclide Lymphoscintigraphy in the Evaluation of Lymphedema by A Szuba et al. JNM, Volume 44, Number 1, January 2003.
[6] MediFocus Guide: Lymphedema. Medifocus.com, Inc, 2004.
[7] The Lymphatic System Pathology by B. Lasinski in "Implications for the Physical Therapists 2-Ed" by C.C Goodman, W.G. Boissonnault, and K.S.Fuller. Saunders 2003, pages 427-508.
[8] The Diagnosis and Treatment of Peripheral Lymphedema: Consensus Document of the International Society of Lymphology. Lymphology 36 (2003) 84-91.
© LymphNotes.com 2006. This information does not replace the advice of a qualified health care professional.
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