PMC4275967_01
Enhanced MDCT images of the tumor. (a) Axial view: the mass compressed the pelvic organs to displace the bladder anteriorly and the rectum to the right. The left internal iliac artery was involved in the tumor, and the inferior gluteal artery ran through the tumor. (b) Sagittal view: the mass passed through the infrapiriform foramen. (c) Coronal view: the mass extended to the left buttock and manifested with a dumbbell-like shape on the image. P: piriformis muscle, ST: sacrotuberous ligament.
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MDCT (multi-detector-row CT) examination revealed a huge, the maximum diameter was 21 cm in size, well-defined mass that occupied almost all of the pelvic space and extended to the left buttock through the greater sciatic foramen (Fig. 1). Magnetic resonance imaging showed that the mass had an iso-intensity equivalent to that of fat, suggesting an atypical lipoma or well-differentiated liposarcoma.
Intraoperative view of the giant tumor. (a) View of the tumor through the buttock. The right side was directed cranially. The dot lines show the sacrotuberous ligaments below the tumor. (b) Pelvic view. The superior gluteal artery and sacral spinal nerves (S1, S2) were preserved. (c) A plastic bag was pulled out abdominally to remove the whole tumor. T: tumor, GM: gluteus maximus, CIV: common iliac vein, IIA: internal iliac artery, S: sacral spinal nerves, U: ureter.
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The skin was incised along the left margin of the sacrum and the sacral side of the gluteus maximus muscle was divided to expose the tumor following marginal dissection of the gluteal part of the tumor (Fig. 2a). The involved left internal iliac artery was divided distal to the superior gluteal artery (Fig. 2b). After completion of the dissection, the plastic bag was raised up to the abdomen, resulting in complete removal of the whole tumor (Fig. 2c).
Macroscopic view of the dissected specimen.
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The tumor was a lobulated mass of adipose tissue measuring 21 x 17 x 3 cm in size, 860 g in weight (Fig. 3).