Malignant Transformation of an Intracranial Extradural Epidermoid Cyst into Squamous Cell Carcinoma Presented with Cerebrospinal Fluid Leakage

Abstract

We report a case of malignant transformation of an intracranial extradural epidermoid cyst into squamous cell carcinoma (SCC), that presented with cerebrospinal fluid (CSF) leakage at the time of recurrence. Intracranial epidermoid cysts are histologically benign and slow-growing neoplasms. They are congenital lesions that develop from ectodermal remnants during neuroembryogenesis. Malignant transformation of epidermoid cysts into SCC is very rare. Various clinical presentations of these tumors after malignant transformation are mentioned in the literature. None of the previous cases, presented with CSF leakage as the recent case did. In cases of malignant transformation, surgical resection and then adjuvant radiation therapy are highly recommended.

Intracranial squamous cell carcinoma of the cerebello-pontine angle mimicking a cystic acoustic schwannoma. A case report with discussion of differential diagnosis and review of literature

“…Intracranial epidermoid cysts are congenital lesions that develop from ectodermal remnants during neuroembryogenesis representing 0.2%-1.8% of all intracranial tumors and 7% of CPA tumors [5] .…”

Lumbar laminotomy and replantation for the treatment of adult spinal epidermoid cyst

“…Surgery is the preferred treatment for symptomatic lesions. [ 2 , 3 ] Lumbar laminectomy and facetectomy are performed to clearly reveal the spinal tumors. However, total facetectomy and laminectomy often cause postoperative lumbar instability and severe low back pain may persist even in the long term.…”

“…[ 2 ] Although epidermoid cyst is a slow-growing benign tumor, there is also a possibility of malignancy. [ 3 , 4 ] Surgical resection of the tumor is the preferred treatment for intramedullary and intradural extramedullary epidermoid cyst. [ 2 , 5 ] Lumbar laminectomy and tumor removal was a routine surgical procedure according to the literature, but long-term postoperative lumbar instability or intractable low back pain and other complications may occur.…”