Piriformis syndrome as a result of intramuscular haematoma mimicking cauda equina effectively treated with piriformis tendon release

Abstract

We present a case of piriformis syndrome in a woman in her 30’s following low energy trauma, presenting with unilateral lower limb weakness, altered sensation and urinary retention. CT imaging revealed a bulky piriformis muscle which was further clarified on MRI as an intramuscular haematoma within the left piriformis causing compression of the left lumbosacral plexus. Haematoma formation was exacerbated due to use of an antiplatelet medication the patient was taking for Moyamoya disease, which carries an increased risk of cerebrovascular accident. Surgical exploration of the piriformis and sciatic nerve was undertaken and confirmed a haematoma within the piriformis. A full release of the piriformis tendon was undertaken, and the sciatic nerve was inspected, no further abnormality was found. After review in clinic post-discharge, the patient reported normal sensation and normal muscle power in her feet.

Atypical lipoma of the right piriformis muscle: a case report and review of the literature

“…Of note, intrapiriformis lesion enlarging the muscle may be the common cause of sciatic nerve compression-induced secondary PS, whereas PS triggered by space-occupying lesions of the piriformis muscle is very rare. To the best of our knowledge, only 11 cases have been reported in the literature thus far; these patients and our present case are summarized in Table 1 [ 4 – 10 ], among which only 1 case of intramuscular lipomas occurring within the piriformis muscle leading to secondary PS have been previously reported in the literature [ 6 ].…”

“…[ 9 ] 2022 71/M L – Radiation therapy Rectal cancer Naoko Sanuki et al . [ 9 ] 2022 80/M L – Radiation therapy Bladder cancer Thomas Robert William Ward et al [ 10 ] 2022 36/F L – Surgical exploration Hematoma Present case 50/M R 6 × 2.3 × 2.6 cm Excision Intramuscular lipoma …”

“…PS triggered by space-occupying lesions of the piriformis muscle is very rare. Up to date, only 11 cases of piriformis muscle mass have been reported in the English literature [ 4 – 10 ].…”