Intussusceptive angiogenesis facilitated by microthrombosis has an important example in angiolipoma. An ultrastructural and immunohistochemical study.
Date
2023Abstract
The microvasculature of angiolipoma
frequently presents thrombi. Our objectives are to assess
whether intussusceptive angiogenesis (IA) participates in
vasculature formation in non-infiltrating angiolipoma
and, if so, to explore how thrombi are involved in the IA
process. For this purpose, we studied angiolipoma
specimens (n: 52), using immunohistochemistry, and
confocal and electron microscopy. The results showed
the presence of folds and pillars, hallmarks of IA,
dividing the vessel lumen. Folds showed a cover formed
by reoriented endothelial cells from the vessel wall, or
from newly formed folds, and a core initially formed by
thrombus fragments (clot components as transitional
core), which was replaced by extracellular matrix and
invaginating pericytes establishing numerous peg-andsocket junctions with endothelial cells (mature core). A
condensed plasmatic electron-dense material surrounded
and connected folds and pillars with each other and with
the vascular wall, which suggests a clot role in fold/pillar
arrangement. In conclusion, we contribute to IA
participation in capillary network formation in
angiolipoma and the immunohistochemical and
ultrastructural events by which microthrombosis
facilitates IA. Therefore, in addition to the histogenesis
of angiolipoma, we provide an easily obtainable
substrate for future studies on clot component action in
IA, of clinical and therapeutic interest.