Ultrastructure of Myopericytoma: A Continuum of Transitional Phenotypes of Myopericytes
- 28 March 2012
- journal article
- Published by Taylor & Francis Ltd in Ultrastructural Pathology
- Vol. 36 (3), 189-194
- https://doi.org/10.3109/01913123.2012.655855
Abstract
The authors report the ultrastructural characteristics of myopericytoma, a recently described variant of perivascular (pericytic) tumors, mainly with regard to their myopericytic cells and vessels. Myopericytes range between pericytes and vascular smooth muscle cells (SMCs) in a morphologic continuum. The principal findings of the intermediate phenotypes are (1) elongated or annular morphology with processes of varying length and thickness (usually long and thin); (2) a continuous, irregularly thickened and zonally duplicated basement membrane; (3) heterocellular “peg and socket” junctions with neighboring endothelial cells, and scarce specialized junctions between myopericytes; (4) numerous micropinocytotic vesicles, whether continuous or forming focal rows; (5) abundant thin microfilaments, grouped in bundles with dense bodies and adhesion plaques; (6) poorly developed synthetic system (RER and Golgi); (7) pseudointracellular bodies formed by invagination of basement and plasma membranes, with numerous endocytic vesicles; and (8) zones of cytoplasmic rarefaction near micropinocytotic vesicles and intracellular organelles. The ultrastructure of myopericytes therefore makes it possible to distinguish them from pericytes, SMCs, and fibroblast/myofibroblasts, which is useful for myopericytoma diagnosis. The main pattern of the vessels, with perivascular concentric and multilayered growth of myopericytes (a thick wall in contrast to a small lumen) and lack of elastic material, also supports an intermediate form between pericytic and muscular microvasculature. The presence of myopericytes more similar to SMCs and of hemangiopericytoma-like vessels concurs with transitional forms with angioleyomyoma and true hemangiopericytoma, histogenetically representing a morphologic continuum for the perivascular tumors.Keywords
This publication has 15 references indexed in Scilit:
- Myopericytoma and arterial intimal thickening: the relationship between myopericytes and myointimal cellsJournal of Cutaneous Pathology, 2011
- Malignant Myopericytoma-like Tumor in a Fischer RatToxicologic Pathology, 2008
- Intravascular myopericytoma of the oral mucosa: a rare histologic variant in an uncommon locationVirchows Archiv, 2007
- Myopericytoma of Skin and Soft TissuesThe American Journal of Surgical Pathology, 2006
- Intravascular myopericytomaJournal of Cutaneous Pathology, 2002
- Perivascular myoma: Case report with immunohistochemical and ultrastructural studiesPathology International, 2002
- Myofibromatosis in Adults, Glomangiopericytoma, and MyopericytomaThe American Journal of Surgical Pathology, 1998
- Cutaneous adult myofibroma: a vascular neoplasmJournal of Cutaneous Pathology, 1996
- Myofibromatosis-like Hemangiopericytoma Metastasizing as Differentiated Vascular Smooth-Muscle and MyosarcomaThe American Journal of Surgical Pathology, 1992
- Der feinere Bau der BlutcapillarenBrain Structure and Function, 1923