Malignant transformation of intracranial epidermoid cyst with leptomeningeal carcinomatosis: case report.
BACKGROUND
Although rare, the malignant degeneration of epidermoid cysts is well documented. Its occurrence with leptomeningeal dissemination and malignant cells in CSF is scarce. To the best of our knowledge only four cases have been reported.


METHODS
The authors report the case of malignant transformation of an epidermoid cyst with leptomeningeal carcinomatosis (which simulates aseptic meningitis) in a 54 year-old woman. Changes in CSF and radiological features are not correlated with the clinical course. Despite improvement of both the lesions on the scan images and the malignant cells in the CSF under chemotherapy the patient died.


CONCLUSIONS
The differential diagnosis of malignant degeneration of epidermoid cyst, and leptomeningeal carcinomatosis are discussed. The diagnosis of malignant transformation should be retained when MRI (or CT scan) shows contrast enhancement at the epidermoid site, and malignant cells are detected in CSF The prognosis is generally poor.
Department of Neurosurgery, CHRU Pontchaillou, Rennes, France. hamlat.abd@wanadoo.fr
Abderrahmane
A
Hamlat
Zi Fen
ZF
Hua
Stephan
S
Saikali
Joelle
J
Egreteau
Yvon
Y
Guegan
D001927:Brain Diseases / Q000473:pathology* / Q000628:therapy; D002277:Carcinoma / Q000556:secondary* / Q000628:therapy; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D003937:Diagnosis, Differential; D004814:Epidermal Cyst / Q000473:pathology* / Q000628:therapy; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008577:Meningeal Neoplasms / Q000556:secondary* / Q000628:therapy; D008582:Meningitis, Aseptic; D008875:Middle Aged