PAPER PRESENTED IN THE 19º INTERNATIONAL CONGRESS OF LYMPHOLOGY - SEPTEMBER 4-6, 2003 - FREIBURG, GERMANY.

INTRODUCTION
The presence of lymphedema means that lymphatic system and every protective mechanism against high protein edemas have been overwhelmed. From this moment, pathological changes in tissues follow the development of this illness. We refer to this sequence of changes produced by lymphedema as the “Chain of events” that mark the progression of the lymphatic disease.

LYMPHEDEMA - CHAIN OF EVENTS

It enables to establish an accurate correlation among pathophysiology, clinical features, computerized tomography imaging and limb morphology. Thus, in a horizontal cut we are able to establish stages. Each stage is formed by a corresponding pathophysiological grade, clinical aspects, CT image and characteristic morphology of the affected limb. Similarly, a vertical cut draws a distinction into five stages of lymphedema which can be assessed according to that association.
 

EDEMATOUS PHASE
• Corresponds with stage I of the Histological-clinical-densimetric classification (HCDC) of extremity lymphedema.

• High protein edema.

• Tissue consistence: soft.

• Pitting edema.

• Improvement by elevation of limbs.

• CAT Scan. Subcutis: small quantity of fibrotic circular bands, sometimes hardly perceptible. Its density fluctuates between -150 and -110 HU (Hounsfield Units) (normal: =/~ -150 HU).

• Limb morphology: slight difference to normal (comparing affected and not affected limbs).
 

Stage I. CAT Scan. Subcutis: Small quantity of fibrotic circular bands	Stage I. Slight difference between limbs.

 

FIBROEDEMATOUS PHASE

• Corresponds with stage IIA of the HCDC.

• Tissue consistence: elastic (like "rubber").

• Pitting edema.

• Slight improvement by elevation of limbs.

• CAT Scan. Subcutis characteristics: regular amount of fibrotic circular bands. Its density fluctuates between -110 and -60 HU.

• Limb morphology: difference between limbs is more evident than previous stage.

Stage II. CAT Scan: moderate fibrosis.	Stage II. Moderate difference between limbs

Stage III. CAT Scan: rich in fibrosis.	Stage III. Marked difference between limbs

Stage IV. CAT Scan: Honeycomb pattern.	Stage IV. Difference strongly marked between limbs.

(From Földi)

CONCLUSION
The explanation and interpretation of phenomenon caused by lymphedema allow us to have an accurate view of the illness and to place each patient in the correct point of the disease in order to apply the form of treatment that will best favour him. In this sense, we also emphasize the importance of lymphoscintigraphy.

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