Development of an Undifferentiated Pleomorphic Sarcoma After Aortic Aneurysm Graft Replacement: A Case Report and Literature Review

Abstract

Aortic sarcomas are extremely rare. Sarcomas associated with aortic graft replacement are even rarer; only 17 cases have been examined through immunohistochemical staining to date, most of which were either angiosarcomas or intimal sarcomas. Here, we report the case of an 88-year-old man with an undifferentiated pleomorphic sarcoma (UPS) that developed after aortic graft replacement and was diagnosed through postmortem autopsy. To the best of our knowledge, this is the first case of graft-associated sarcoma diagnosed as an undifferentiated pleomorphic type following detailed immunohistochemical staining with sufficient antibodies and fluorescencein situ hybridization (FISH).

Keywords: aortic graft; autopsy; histopathology; post-mortem diagnosis; sarcoma; undifferentiated pleomorphic sarcoma.

Figure 1. Imaging findings over time

(A) Contrast-enhanced computed tomography (CECT) image acquired 22 months before death (i.e., 37 months postoperatively). The arrow shows a seroma-like, low-density area around the Y-shaped graft in the abdominal aorta and common iliac arteries. (B) A contrast-enhanced, T1-weighted magnetic resonance image obtained 15 months before death (i.e., 44 months postoperatively) shows that the mass increased to approximately 10 × 9 cm. (C) A simple CT scan obtained five months before death (i.e., 54 months postoperatively) shows further enlargement of the mass. The arrows indicate the site of ureteral stent replacement. (D, E, and F) Simple CT scans obtained 59 months postoperatively show the horizontal, coronary, and sagittal sections, respectively. A mass, measuring approximately 17 × 16 × 12 cm in each section, is noted in the retroperitoneum.

Figure 2. Macroscopic details of the tumor

(A) The mass (2470 g) surrounding the Y-graft in the abdominal aorta and common iliac arteries. Ao indicates the aorta. (B) A schematic illustration of Figure A showing the mass, aorta, common iliac arteries, and Y-graft (blue). The mass is divided almost equally into five sections named Ⅰ through Ⅴ. The arrow indicates the outline of the mass. Ao, R, and L indicate the aorta, right common iliac artery, and left common iliac artery, respectively. (C) Cross-section of the mass surrounding the Y-graft (white arrows) in section Ⅱ. The black arrows indicate the ureters. The inferior vena cava is open (black arrowhead). rU and ltU indicate the right ureter and left ureter, respectively. Figure 2B has been created by Masaki Sano and Kazunori Inuzuka.

Figure 3. Histology and immunostaining for the tumor

(A, B) Hematoxylin and eosin staining of the tumor. (A) The proliferation of spindle-shaped and atypical cells is observed, and a partially storiform pattern is visible (×100). (B, C) Nuclear atypia is observed (×200). (D) Prominent nucleoli and bizarre nuclei are scattered throughout (×400). (E) CD68, (F) AE1/AE3, (G) α-SMA, (H) CDK4, (I) MDM2, (J) p53, and (K) Ki-67 staining of the tumor (×100). The tumor cells are positive for CD68, AE1/AE3, and p53. Scale bars = 100 µm (A, E, F, G, H, I, J, and K), 50 µm (B, C), and 25 µm (D).