extremely common, benign vascular tumors. They are the mostcommon tumor in
infants appearing on the skin, mucous membranes, or internal organs. The major
types are capillary and cavernous hemangiomas. Hemangiomas may spontaneously
are associated with von Hippel-Lindau disease, which
maycause multiple hemangioblastomas involving the cerebellum, brain stem, spinal
cord, and retina, as well as renal cell carcinoma.
tumors (glomangioma) are benign, small, painful tumors of the
glomusbody that usually occur under fingernails.
sarcoma is a malignant tumor of endothelial cells associated with
Kaposi-sar-coma–associated virus (HHV8). The condition causes multiple
red-purple patches, plaques, or nodules that may remain confined to the skin or
may disseminate. Microscopically, there is a proliferation of spindle-shaped
endothelial cells with slit-like vascular spaces and extravasated erythrocytes.
The classic European form occurs in
older men of Eastern European or Medi-terranean origin, who develop red-purple
skin plaques on the lower extremities.
The transplant-associated form occurs in patients on immunosuppression
for organ transplants; involves skin and viscera; may regress with reduction of
The African form occurs in African children and young men in whom
gen-eralized lymphatic spread is common.
The AIDS-associated form is most common in homosexual male AIDS
patients; it is an aggressive form with frequent widespread visceral
dissemi-nation. Common sites of involvement include skin, GI tract, lymph
nodes, and lungs. This form of Kaposi sarcoma is responsive to chemotherapy and
interferon-alpha, and only rarely causes death.
is a malignant vascular tumor with a high mor-tality that most commonly occurs
in skin, breast, liver, and soft tissues. Liver angio-sarcomas are associated
with vinyl chloride, arsenic, and thorotrast.