Terminal myelocystoceles: a series of 17 cases

A terminal myelocystocele is a rare form of spinal dysraphism in which the hydromyelic caudal spinal cord and the subarachnoid space are herniated through a posterior spina bifida. In their study of 17 cases, the authors attempt to develop treatment guidelines for patients suffering from this condition.

Seventeen patients (age range 2 months-5 years) underwent surgery during a 7-year period. Surprisingly, nine of 17 patients had no neurological deficits. Among these nine asymptomatic cases, three patients had a dermal sinus and two had a skin dimple, whereas one had congenital talipes equinovarus deformity (CTEV). Among the eight patients with neurological deficits, seven had lower-limb weakness (two had complete paraplegia), and one patient had urinary incontinence and constipation. Four patients each had a dermal sinus and CTEV; interestingly, one infant had an accessory phallus. Radiologically, eight patients had pure myelocystoceles, and a diagnosis of lipomyelocystocele was made in nine instances on the basis of magnetic resonance images. All patients underwent surgery. The meningocele sacs were excised, and the bands tethering the myelocystocele sac to the meningocele sacs were incised, with as little damage to the roots as possible. Two patients experienced postoperative CSF leakage (one required reexploration), and two others had subcutaneous CSF collection. No patient had deterioration of the neurological condition after surgery.

The authors present the largest study of patients with terminal myelocystocele to date and emphasize that the possibility of this condition must be kept in mind when addressing all congenital lumbosacral masses. The authors assert that myelocystoceles and lipomyelocystoceles should be kept in the same category and recommend early surgery in all cases.