Spinal extradural inclusion dermoid cyst mimicking pseudomeningocele, appearing after 17 years of meningomyelocele repair
A 17-year-old boy who underwent lumbar meningomyelocele repair at the age of 2 months presented in the outpatient clinic with a progressive globular swelling in the lower half of the back and weakness of left foot for the past 6 months. No history of any alteration in the bladder and bowel habits. On examination a globular cystic mass of 8 cm × 8 cm size was noted at L3, L4 region sitting in the middle of previous MMC repair scar. It is poorly transilluminant and cough impulse was absent. Neurological examination was unremarkable except for weakness of the left foot dorsiflexors, having 4/5 power.\nMagnetic resonance imaging (MRI) LS spine showed a fluid filled globular swelling hypointense on T1 and iso to hyperintense on T2 extending from L3 to L5 [Figures and ]. Axial T2 images show a doubtful communication with the thecal sac at L4/5 level []. Urodynamic flow studies didn’t reveal any abnormality.\nA diagnosis of pseudomeningocele was made and excision of the sac with repair of the dural defect was planned. Intra operatively there was clear plane of cleavage present between the cyst and the skin and subcutaneous tissue. Small portion of the placode was seen pouting out of the thecal sac. The placode is adherent by thick connective tissue layer with the wall of the cyst []. There was no communication between the cyst and the thecal sac. The cyst was removed intact from the placode. Cyst opening revealed a mud colored highly viscous fluid []. Dura was opened and protruding portion of the placode was internalized. Patients’ neurological status remained the same as that of preoperative period at the time of discharge. At 1 year follow-up patient had complete improvement in the left foot weakness. Rest of the neurological examination was unremarkable.