PMC6077880_01
Clinicopathological findings on venous aneurysm of the cephalic vein with possible venous focal dissection (venous dissecting aneurysm). (A) At surgery, a longitudinal skipped incision was performed below the aneurysmal nodules and along the course of left cephalic vein. Multiple cystic and bead-like appearing venous aneurysms were present, measuring 12 x 11 x 10 mm3 or 16 x 14 x 14 mm3, respectively (red arrows). The skin revealed an extensive, pigmented purpura on the medial side of her left upper arm. (B) The transverse section of the aneurysm (H&E stain) showed that a localized and abnormally dilated venous lumen was filled with mixed stratified thrombi, surrounded by variably thinned medial wall with focal, markedly reduced or absent medial smooth muscle layer and elastic fibers. Bar = 2 mm. (C) Elastica van Gieson (EVG) staining clearly revealed complete loss and focal dissection of medial to adventitial elastic fibers in the variably thinned aneurysmal wall (red arrows). Correspondingly, intimal fibromuscular thickening (yellow arrows) was partially recognized, accompanied by increased or decreased elastic fibers. (D) Microscopic findings (H&E stain) showed that there seemed to be an intimal tear (red arrow) extending into the deep layer of media of the aneurysmal vein, accompanied by the connection with the blood-filled vascular channels. Bar = 500 microm. (E) EVG and (F) immunohistochemical smooth muscle actin (alpha-SMA) staining more clearly showed an elastic (E) and fibromuscular (F) tear in the medial wall, associated with reduced/absent and occasionally increased elastic fibers and smooth muscle cells.
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PMC6077880_01_10.1177_1179065218785126-fig1.jpg
fig1-1179065218785126
Since the patient requested surgical resection of the aneurysms, a longitudinal skipped incision was performed below the aneurysmal nodules and along the course of left cephalic vein (Figure 1A). Multiple cystic and bead-like appearing venous aneurysms were present, measuring 12 x 11 x 10 mm3 or 16 x 14 x 14 mm3, respectively (Figure 1A). On the scanning magnification of one aneurysm (Figure 1B), its transverse section showed that a localized and abnormally dilated venous lumen was filled with mixed stratified thrombi, surrounded by variably thinned medial wall with focal, markedly reduced or absent medial smooth muscle layer and elastic fibers. Elastica van Gieson (EVG) staining clearly revealed complete loss and focal dissection of medial to adventitial elastic fibers in the variably thinned aneurysmal wall (Figure 1C). Correspondingly, intimal fibromuscular thickening was partially recognized, accompanied by increased or decreased elastic fibers (Figure 1C) and associated with variously degenerated and fibrous change by the Masson's trichrome or alcian blue staining. Microscopic findings demonstrated that there seemed to be an intimal tear extending into the deep layer of media of the aneurysmal vein, accompanied by the connection with the blood-filled vascular channels (Figure 1D). EVG and immunohistochemical smooth muscle actin (alpha-SMA) staining more clearly showed an elastic (Figure 1E) and fibromuscular (Figure 1F) tear in the medial wall, associated with reduced/absent and occasionally increased elastic fibers and smooth muscle cells (Figure 1C, E and F).