Because of the shared origin of limited dorsal myeloschisis (LDM) and congenital dermal sinus (CDS), CDS elements may be found within the fibroneural LDM stalk. When part of the CDS invested in the intradural stalk is left during untethering surgery, inclusion tumors such as dermoid cysts may develop. However, the most appropriate surgical strategy for LDM with CDS is still under debate. Methods: Of 19 patients with LDM, 3 (15.8%) had histologically verified CDS elements. We retrospectively analyzed the clinicopathological findings of these patients. Results: In patient 1, the entire stalk including a tiny dermoid cyst at the intradural stalk could be resected through two-level laminectomy during untethering at 6 months of age. In patients 2 and 3, the stalk appeared to be a typical LDM stalk during the initial surgery at 18 and 7 days, respectively; however, CDS was histologically diagnosed in the proximal severed end of the stalk. Postoperative three-dimensional heavily T2-weighted imaging demonstrated spherical enlargement of the remnant stalk, and the entire length of the remnant stalk including newly developed dermoid was resected during the second surgery at 3 years 11 months and 11 months, respectively. Histopathologically, glial fibrillary acidic protein-immunopositive neuroglial tissues and CDS elements were mainly located at the proximal and distal sites of the stalk, respectively, supporting the dragging down and pulling up theory. In patients 2 and 3, however, the proximal head of the dermoid cyst passed the distal head of the neuroglial tissues and located at the stalk-cord attachment. Conclusion: Surgeons should be aware of the approximately 10% possibility of the coexistence of CDS when managing infant LDM. However, the recommendation for excision of the entire length of the LDM stalk in all patients should be more carefully made because such a strategy may result in an unnecessary extent of laminotomy/laminectomy for most patients with pure LDM. However, once the postoperative histological examination reveals coexistence of CDS in the resected proximal part of the stalk, the entire length of the remnant stalk should be excised as soon as possible.
All Science Journal Classification (ASJC) codes
- Pediatrics, Perinatology, and Child Health
- Clinical Neurology