The radiologist has a most important part to play in the diagnosis and management of this disease. He or she can frequently recognize it accurately, even before the clinical diagnosis has been made. The radiological findings fall into the following categories.
1. The soft tissues
2. Skeletal lesions
3. Abdominal and thoracic lesions
4. The lymphatics.
Soft Tissues (including Angiography)
The Kaposi nodules may be demonstrated by high quality soft tissue radiographs, preferably obtained by using small focal spot tubes and fine grain film. Such techniques will often demonstrate nodules below the surface, as well as those that are clinically visible. It is a reliable way of estimating the extent of the disease (Figs. 42.9, 42.10).
Fig. 42.9 A-D. Edema of the foot and multiple nodules in Kaposi sarcoma. (A) Large soft tissue nodules surrounding the foot. There is generalized osteoporosis. (B) Thick edema of the dorsum and sole of the foot with multiple nodules and marked osteoporosis. (C) Marked edema and osteoporosis. The nodulation is not so evident. (D) Marked osteoporosis with little nodulation or soft tissue swelling. There is no firm relationship between the extent of osteoporosis and the degree of edema.
Fig. 42.10A,B. Bilateral Kaposi sarcoma. In (A) there is more edema and less osteoporosis than in (B). There is more bone involvement in B.
Soft tissue angiography and MRI are important examinations in Kaposi sarcoma. Many nodules will be demonstrated which cannot be palpated or otherwise diagnosed and their progress can be assessed. It is important that, even when there is a solitary Kaposi nodule, soft tissue examinations should be carried out to exclude other tumors. When the sarcoma is first seen in one leg, MRI or angiography should include both lower limbs: if it is first seen on an arm or on the body, then all four limbs should be examined. Involvement of the lower limbs occurs in such an overwhelming majority of HIV-negative Kaposi patients that it is essential that the full extent of the disease be accurately recognized before treatment is initiated, especially if radiotherapy is considered.
Copyright: Palmer and Reeder