Age:
Occurs in young adults
Site:
These subcutaneous tumours are usually located on the forearm, arm and
chest wall.
Clinical presentation:
Presents as multiple,
painful yellow , firm, circumscribed tumours. Angiolipoma usually do
not recur after excision. New lesions may continue to develop elsewhere. Microscopic features:
-Thin fibrous capsule with fibrous
septa dividing the lesion into lobules.
-There are mature adipocytes together with groups of small vessels .
- Presence of
fibrinous
microthrombi in the lumen is
a diagnostic feature.
- In 'cellular angiolipoma' the vascular component is more than 90%.
- Prominent pericytes may be present around the capillaries.
- Numerous mast cells are noted throughout the tumour.
- Degenerative changes (i.e. hyalinization, myxoid change and fibrosis)
may be present in longstanding cases.
- Angiomyxolipoma is characterized by myxoid stroma. Unlike angiolipoma
which has normal karyotype, angiomyxolipoma shares cytogenetic changes
with
lipoma,
spindle cell lipoma
and myxoma. Cytogenetic:
Normal karyotype
Differential diagnosis: One must exclude
well-differentiated angiosarcoma of the breast from angiolipomas arising
on the chest wall.
Cellular angiolipomas may resemble Kaposi Sarcoma or primitive capillary
hemangioma.
