PMC5613361_01
(a) Computed tomography (CT) of the abdomen. Green arrow showing the large pelvic mass. (b) Sagittal view-Magnetic Resonance Imaging (MRI). Yellow arrow showing the tumor.
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Computed tomography (CT) of the abdomen and pelvis revealed an approximately 10 x 10 cm tumor in the retroperitoneal space, immediately anterior to the aortic bifurcation, high in the pelvis, and posteriorly to the upper third of the rectum (Figure 1(a)). Magnetic resonance imaging (MRI) of the pelvis followed and confirmed the solid nature of this mass, showing that it was independent from the bowel/rectum, featuring a retroperitoneal sarcoma type of mass rather than a lymph nodal bloc (Figure 1(b)). The neoplasm had minimal pleomorphism, no atypia, and rare mitotic figures (<1 mitoses per 10 High Power Fields).
(a) Macroscopic view of the surgical specimen. (b) Intraoperative view of the pelvis, after tumor resection. Total mesenteric excision plane was entered.
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The left colon was mobilized and the total mesorectal excision (TME) surgical plane was entered; the tumor was mobilized and excised in clear margins macroscopically without any intraoperative adverse events (Figures 2(a) and 2(b)).
(a) Microscopic view (H-E x100) of bland and uniform oval to spindle cells with minimal cytoplasm, small elongated nuclei, and indistinct nucleoli. (b) Immunohistochemical examination with positive staining for CD34.
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Histopathological examination showed a neoplasm composed of bland and uniform oval to spindle cells with minimal cytoplasm, small elongated nuclei, and indistinct nucleoli (Figure 3(a)). Immunohistochemical examination showed positive staining for Bcl-2, CD34 (Figure 3(b)), vimentin, and CD99 while desmin and S-100 were negative.