Figures
Figure 1. Magnetic resonance images obtained at first examination. There is an enhanced mass (8 cm in diameter) attached to the urinary bladder arising from the internal obturator muscle. The tumor shows a moderately low signal intensity comparable to skeletal muscles on T1-weighted images (a), a moderately high signal intensity on T2-weighted images (b), and high enhancement with a partially mottled pattern after intravenous administration of gadolinium contrast agent (c).
Figure 2. Pathological sections of a tissue specimen stained with hematoxylin and eosin. Well-differentiated fibroblasts that do not exhibit dysplasia or abnormal fission proliferation have infiltrated the skeletal muscles.
Figure 3. Magnetic resonance images obtained at 2 years and 3 months after surgery (a: T1-weighted images; b: T2-weighted images; c: gadolinium contrast). The patient had tumor recurrence that was evident as two enhanced masses (1 cm in diameter) located a little behind the preoperative point, namely the right internal obturator muscle.
Figure 4. Magnetic resonance images of the two masses obtained at 3 years and 2 months after surgery (a: T1-weighted images; b: T2-weighted images; c: gadolinium contrast). These masses reached a maximum size of 1.8 cm in diameter.
Figure 5. Magnetic resonance images of the two masses obtained at 5 years and 4 months after surgery (a: T1-weighted images; b: T2-weighted images). The masses have not increased in size.
Figure 6. Magnetic resonance images obtained at 8 years and 4 months after surgery (a: T1-weighted images; b: T2-weighted images; c: gadolinium contrast). The enhanced masses have disappeared.