Retained foreign body misdiagnosed as a low flow vascular malformation: A case report.

A 21-year-old woman presented with 1 year history of progressive dorsal right foot pain with no recollection of trauma. The physical exam did not reveal any unusual appearance to the plantar or dorsal skin surfaces. Specifically, no scars were seen. Foot radiographs were unremarkable. The presumed etiology after Doppler ultrasound (US) and MRI was a likely venous or venolymphatic malformation. She received 2 rounds of sclerotherapy 12 months apart with transient symptomatic clinical improvement. After the second sclerotherapy treatment, repeat MRI revealed dorsal extension of the lesion with skin involvement, prompting referral for surgical intervention. At surgery, a 3 cm wood splinter was found surrounded by granulation tissue. After showing the patient the resected splinter, she recalled stepping on a wooden broomstick that punctured the bottom of her foot in her childhood. She stated she also remembered pulling a splinter out of her foot. This case demonstrates the unusual and rare appearance of a chronic retained foreign body creating a cystic lesion in the foot presumed to be a low-flow vascular malformation on US and MRI.