Dethlefsen S M, Mulliken J B, Glowacki J
Ultrastruct Pathol. 1986;10(2):175-83. doi: 10.3109/01913128609014593.
Hemangiomas, the most common tumors of infancy, are characterized by a postnatal period of rapid growth, followed by a phase of gradual involution. The proliferative phase is characterized by increased numbers of endothelial and mast cells and thickened basement membrane. Ultrastructural analysis of hemangiomas in the late proliferative phase showed that mast cells had numerous fingerlike processes aligned parallel to the outer lamina of the thickened basement membranes surrounding the vessels and to the surfaces of opposing cell membranes. We found evidence of different types of interactions between mast cells and adjacent connective tissue cells (fibroblasts, macrophages, multinucleated giant cells, and plasma cells) in the perivascular regions of the lesions. Intercellular contacts were observed in areas where these mast cell processes were in close association to the opposing cell membrane. Areas of membrane fusions were seen between cell types. Coated vesicles and pinocytotic vesicles were present along the periphery of cells adjacent to mast cells. Occasionally, cytoplasmic bridges were found between mast cells and fibroblasts. These ultrastructural findings suggest the proliferation and involution of hemangiomas are determined by interactions between the various types of cells found in the lesions.
血管瘤是婴儿期最常见的肿瘤，其特点是出生后快速生长，随后进入逐渐消退阶段。增殖期的特征是内皮细胞和肥大细胞数量增加以及基底膜增厚。对增殖后期血管瘤的超微结构分析显示，肥大细胞有许多指状突起，这些突起与围绕血管的增厚基底膜的外层以及相对细胞膜的表面平行排列。我们在病变的血管周围区域发现了肥大细胞与相邻结缔组织细胞（成纤维细胞、巨噬细胞、多核巨细胞和浆细胞）之间不同类型相互作用的证据。在这些肥大细胞突起与相对细胞膜紧密相连的区域观察到了细胞间接触。在不同细胞类型之间可见膜融合区域。在与肥大细胞相邻的细胞周边存在有被小泡和吞饮小泡。偶尔，在肥大细胞和成纤维细胞之间发现了细胞质桥。这些超微结构发现表明，血管瘤的增殖和消退是由病变中发现的各种类型细胞之间的相互作用所决定的。
