case_images: PMC7738235_01
case_images: A 21-month-old boy presenting with extensive venous malformation in the perineum and pelvis. (
  A
  ) Complicated presentation with chronic bleeding from a fungating skin ulcer. (
  B
  ) After 3-month treatment with oral sirolimus showing marked improvement of skin lesions. (
  C
  ) Pelvic magnetic resonance imaging (T2WI with fat suppression): axial cuts through the perineum to demonstrate the extension of the lesion that appeared as hyperintense dilated venous lakes.
case_images: 10-1055-s-0040-1716895-i200528cr-1.jpg
case_images: PMC7738235_01_10-1055-s-0040-1716895-i200528cr-1.jpg
case_images: FI200528cr-1
case_images: A 21-month-old boy was referred to our vascular anomaly clinic with extensive vascular malformation in the perineum and pelvis ( Fig. 1 ). At day 2 of life, he had bleeding from a scrotal lesion for which a trial of surgical ligation failed resulting in a fungating skin ulcer with persistent chronic bleeding ( Fig. 1A ). He had a pelvic magnetic resonance imaging (MRI) study already performed before referral that showed the presence of extensive venous malformation involving the pelvis, perineum, scrotum, and extending to the gluteal region ( Fig. 1 ).
case_images: Axial imaging demonstrating the deep pelvic component of the venous malformation. The venous malformation is seen totally encasing the anorectum with marked thickening of their walls almost occluding their lumen. The upper row (
  A
  ,
  B
  ): magnetic resonance imaging study performed before referral to our vascular clinic. The lower row (
  C
  ,
  D
  ): computed tomographic angiography performed 2 months later. Note the patchy and delayed contrast enhancement of the lesion typical for venous malformation. By comparing both studies (upper row with lower row), no appreciable changes could be detected in the deep pelvic component of the lesion in contrary to the external clinical improvement.
case_images: 10-1055-s-0040-1716895-i200528cr-2.jpg
case_images: PMC7738235_01_10-1055-s-0040-1716895-i200528cr-2.jpg
case_images: FI200528cr-2
case_images: T1WI, with typical delayed patchy contrast enhancement ( Fig. 2 ). The lesion was seen totally encasing the anorectum with marked thickening of the rectal wall almost occluding the bowel lumen ( Fig. 2 ). The patient was admitted on intravenous tranexamic acid and intravenous iron replacement (once). Over a follow-up period of 5 months, the skin lesions showed continuous improvement ( Fig. 2B ) with no detectable side effects for the drug.  A follow-up imaging (computed tomographic angiography) was performed 2 months after the start of sirolimus treatment ( Fig. 2 ). Contrarily to the marked clinical improvement (regarding pain, mucosal bleeding, and skin changes), no appreciable changes could be detected in the deep pelvic component of the lesion ( Fig. 2 ).