gms | German Medical Science

Diastematomyelia is a rare entity of split spinal cord malformations, which is rarely found in the cervical region. Typically associated with cutaneous findings and vertebral anomalies, sporadic cases of concurrent intradural or intramedullary spinal cord tumors can be found. Few reports of epidermoids with diastematomyelia are available, all of them with the epidermoid cyst located inside the hemicord.

We present the unique case of a 2-year-old boy, who has a combination of these individually considered rare anomalies. The patient had a hypertrichosis in the cervicothoracic region since he was born. Although he showed a completely normal development, further radiological examination was initiated because of a distinct scoliosis. After initial plain radiographs indicated the possibility of complex vertebral anomalies in the upper thoracic spine, a MRI of the whole spinal column revealed a mid-cervical diastematomyelia and a syrinx, located caudally in the vicinity of the split cord malformation. High-resolution CT scan reconstructions demonstrated the complex vertebral body anomalies in the lower cervical and upper thoracic spine.

During surgery two symmetrical hemicords and a thin fibrous structure running in the midline sagittally through the upper third of the diastematomyelia were found. More ventrally between the upper portion of the two hemicords, a solitary, round tumor, containing viscous yellow fluid was visible. The complete tumor, which showed no infiltration of the hemicords, was removed and ventrally located adhesions were released. Histologically, the mass was classified as an epidermoid cyst. Postoperatively the patient remained without any neurological deficits.

This case is remarkable, not only because of the rare coincidence of a mid-cervical split spinal cord malformation and multiple vertebral body anomalies in the cervico-thoracic-junction in an almost asymptomatic child, but also because of the unexpected intraoperative finding in terms of an epidermoid cyst lying intradurally between the two hemicords. Previous publications describe either cases of intradural epidermoid tumors located in the spinal cord, other intramedullary tumors, neurenteric cysts, or a dermal sinus with or without dermoid cysts coexistent with diastematomyelia. We found this epidermoid cyst between the hemicords, not visible on the preoperative MRI in our patient, indicating its origin in a rather complex embryological malformation.