Fig. 13

Histopathological demonstrations before and after lipiodol-based INL and INE. The upper row shows an unaffected lymph node structure with outer capsule and subcapsular sinuses, lymphoid follicles (*), and uniform extrafollicular regions (exFs) in the cortex with extended trabeculae and trabecular blood vessels; in each follicle, germinal center (GC) and mantle zone (MZ) are sharply demarcated; besides, there are contact sinuses and moderate histiocytosis beneath the capsule. The second row shows a parenchymal defect of the needle tract with surrounding hemorrhage and focal necrosis. The third row shows extensive empty spaces within the dilated sponge-like sinuses (black arrows) and dilated blood vessels (asterisks) after lipiodol-based INL due to the histological preprocessing. The fourth row shows the restoration of extensive empty spaces without any persistent parenchymal injury 6 days after lipiodol-based INL. The lowest row shows the glue (black arrowhead) injected in INE was seen both within the sinuses (black arrows) and trabecular blood vessels (TBVs), with mildly focal nuclear pyknosis and partial loss of intercellular borders after 6 days. All images were from Pig No. 7&8 under standard HE stains. Notes: *, lymphoid follicle; asterisk, blood vessel; black arrow, lymphatic sinus; black arrowhead, consolidated glue framework. Abbreviations: GC, germinal center; MZ, mantle zone; exF, extrafollicular zone; TBV: trabecular blood vessels; INL, intranodal lymphangiography; INE, intranodal embolization