Presentation
Intermittent right shoulder pain, worse during physical activity.
Patient Data
Other than a calcified phlebolith, vascular spaces fully compress and immediately full up upon release of pressure on the ultrasound probe. No notable spontaneous flow on Doppler (not shown). Along with history and physical exam, findings are highly suggestive of a venous malformation.
Lobulated high T2WI lesion within the intermuscular fat behind the right deltoid muscle. Internal low T2WI areas (phleboliths). Mildly elevated T1WI signal compared to skeletal muscle. Interspersed fat between lobulations. Central enhancement on early post-gadolinium imaging.
Selected DSA images during percutaneous polidocanol foam sclerotherapy with 22- and 23 G needles. Early on, minimal venous drainage is seen, but as the cavitary lesion becomes thrombosed during the procedure, outflow veins are no longer seen.
Case Discussion
Typical findings of a soft-tissue venous malformation per the ISSVA classification.
Physical exam, history and dynamic ultrasound are the keys to making the diagnosis. Compressibility of the lesion helps distinguish venous malformations from macrocystic lymphatic malformations which can appear very similar on static 2D images and MRI but are not compressible. MRI is especially useful in defining the extent of involvement, especially in deep vascular malformations, which might be underestimated on ultrasound.
Gadolinium injection is not necessary for imaging slow-flow vascular malformations on MRI. Enhancement of venous malformations will be variable depending on the delay of imaging after injection and whether the lesion is fully permeable or partially thrombosed.