case_images: PMC7399171_01
case_images: Axial (1a), sagittal (1b), and coronal (1c) CT scan of the abdomen without IV contrast obtained initially for renal colic. There is a well-defined oval paraspinal soft tissue mass (arrow) within the left psoas muscle (asterisk). The mass is heterogeneously hyperdense with foci of calcifications. The left kidney is displaced anteriorly (arrowhead).
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case_images: Unenhanced CT abdomen was done to rule out renal stones which showed left psoas muscle well-defined heterogeneous soft tissue mass (Fig. 1: a-c).
case_images: Axial T1 (2a), T2 (2b), and post-contrast T1-weighted (2c) MRI images showed well-defined T1 hypointense, T2 heterogeneous hyperintense, and heterogeneously enhancing mass in the posterior aspect of the left psoas muscle (arrow). Coronal T2-weighted image (2d) showed fat split sign (arrowhead) indicating intramuscular location of the mass.
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case_images: AP, CC, and TR, respectively (Fig. 2: a-d). After that, he was admitted electively and underwent a two-hour smooth anterior approach of laparoscopic hand-assisted resection of left psoas muscle mass using both splitting and cutting maneuvers through five ports performed by certified surgeon in surgical oncology and minimally invasive surgery (Fig. 3, Fig. 4).
case_images: (3a) Laparoscopic view of the left side of the intra-abdominal cavity showing huge enlargement in left psoas muscle (solid black arrow), left ureter (solid white arrow), left descending colon mobilization sit (non-solid black arrow), and lower pole of left kidney (non-solid white arrow). (3b) The largest piece of the mass which measured 10 x 7.5 x 6.5 cm. The mass was oval with a smooth outer surface and a heterogenous nodular cut surface.
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case_images: AP, CC, and TR, respectively (Fig. 2: a-d). After that, he was admitted electively and underwent a two-hour smooth anterior approach of laparoscopic hand-assisted resection of left psoas muscle mass using both splitting and cutting maneuvers through five ports performed by certified surgeon in surgical oncology and minimally invasive surgery (Fig. 3, Fig. 4).
case_images: (5a) A photomicrograph showing the biphasic nature of the lesion (hypercellular Antoni A areas and hypocellular Antoni B areas) (H&E stain, x100 magnification). (5b) Areas of hyalinization and hemorrhage were present (H&E stain, x100 magnification). (5c) The cells showed elongated wavy nuclei with several Verocay bodies (H&E stain, x100 magnification). (5d) Mild nuclear atypia was present along with hyalinization of several blood vessels (H&E stain, x200 magnification).
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case_images: The postoperative histopathological examination showed the same diagnosis (Fig. 5: a-d).