Primary perianal alveolar rhabdomyosarcoma with uncommon metastatic sites: a case report and follow-up using 18F-FDG PET/CT

Figures

• 

  Figure 1. Enhanced pelvic magnetic resonance imaging (MRI) of a female patient with alveolar rhabdomyosarcoma with multiple metastases. (A–C) Images reveal a thickening of the soft tissue on the right side of the perineum and around the anus with significant enhancement (arrows), extending locally to the anal fissure. (D–F) Multiple enlarged lymph nodes (arrowheads) are observed in the bilateral inguinal regions. A noticeable increase in signal intensity with the short diameter of the largest node measured approximately 1.4 cm after enhancement. (G–I) Multiple nodular and patchy areas of low signal intensity on T1-weighted images (T1WI) and high signal intensity on fat-suppressed T2-weighted images (fsT2WI) are seen in the sacrum (hallow arrowheads).

• 

  Figure 2. 18F-FDG PET/CT images of a female patient diagnosed with alveolar rhabdomyosarcoma along with multiple metastases. (A–C) Anteroposterior three-dimensional maximum intensity projection (MIP) image demonstrates several increased metabolic activity sites. Enlarged lymph nodes (arrowheads) are present in the bilateral inguinal region, and the largest node has a short diameter of approximately 39 mm with increased FDG uptake (SUVmax = 8.9). An irregular soft tissue density mass (hallow arrowheads) is visible around the anus and on the right side of the perineum, measuring approximately 88 mm × 68 mm × 111 mm (AP × RL × SI) with increased FDG uptake (SUVmax = 48.7). (D,E) There is fluid accumulation in the left thoracic cavity and irregular thickening of the left pleura (long arrows) with increased FDG uptake (SUVmax = 8.3). Increased FDG uptake (SUVmax = 8.2) is manifested in the vertebrae, indicating bone erosions (short arrows).

• 

  Figure 3. 18F-FDG PET/CT images of a female patient diagnosed with alveolar rhabdomyosarcoma along with multiple metastases after chemotherapy. (A–C) Anteroposterior three-dimensional maximum intensity projection (MIP) image demonstrates several increased metabolic activity sites. Multiple lymph nodes (arrowheads) remain visible, with the largest lymph node manifesting a short diameter of approximately 39 mm to 10 mm. The lymph nodes next to the right iliac vessel and in the bilateral inguinal areas show increased FDG uptake with SUVmax of 4.2. The irregular soft tissue density mass (hallow arrowheads) around the anus can be seen in the perianal and perineal areas, measuring approximately 55 mm × 52 mm (AP × RL) with a remarkable SUVmax decrease of 9.5 compared to 48.7 before chemotherapy. (D,E) The original bilateral pleural effusion (long arrows) disappeared. Multiple focal FDG uptake lesions can be seen in the L4 and L5 vertebral plates with SUVmax ranging from 8.2 to 5.5 (short arrows). However, multiple skeletal lesions with diffusely increased glucose metabolism are still observed throughout the rest of the body.