Mature midline teratoma arising within a posterior thoracic myelomeningocele in an infant: A case report

Myelomeningocele can occur throughout the spinal axis but the area with the least common localization is the thoracic region which is uncommon. Rarely, these abnormalities coexist with a teratoma and only few reports of a teratoma arising from a myelomeningocele have been reported. Teratoma can also undergo malignant transformation to a non-germ cell malignancy. Here, we report an interesting case of a teratoma arising within thoracic myelomeningocele in an infant. A three month old girl born via vaginal delivery to two related Fulani parents presenting with upper back swelling noticed since birth. Pregnancy was claimed to be uneventful, mother never attended any antenatal clinic and delivery was at home. On examination patient was mildly dehydrated and malnourished. Status localis revealed an intact cystic midline upper back swelling measuring about 6x4cm, non-tender with no differential warmth. Radiographic evaluation was not done due to financial constraint. Grossly, three irregularly shaped firm to cystic to flabby tissues aggregating to 5x4x1.5cm, weighing 6g were received and microscopy revealed histologic features of a myelomeningocele with a teratoma having endodermal (respiratory epithelium, seromucinous glands) , ectodermal( skin) and mesodermal (cartilage) components. Teratoma is a germ cell neoplasm that contains differentiated elements derived from all three germ layers. The occurrence of a mature midline teratoma within a myelomeningocele is rare and what makes it even rarer is occurrence in the thoracic region. This can be confirmed by meticulous histopathologic evaluation. Myelomeningocele has variable prognosis based on localization and other accompanying abnormalities. Due to the risk of malignant transformation to non-germ cell tumours in teratoma, prompt histologic diagnosis and complete resection is important regardless of size of lesion and age of patient.