BACKGROUND. Subcutaneous ependymomas have been reported rarely in dermatologic reviews and, apparently, were never associated with other cutaneous malformations. METHODS. A 60-year-old woman with a retrolumbar subcutaneous ependymoma and a giant bathing-trunk nevocellular nevus submitted to thorough dermatologic and neurologic investigation. The surgical material was extensively analyzed with light and electron microscope. The literature was reviewed. RESULTS. The tumor fits exactly the classical prerequisites of the clinical and pathologic diagnosis. In contrast with the literature, it developed at 53 years, apparently after a trauma, within a congenital giant nevocellular nevus, at the retrolumbar level; it proved unrelated to any spinal cord alteration and so far appeared quite benign. CONCLUSIONS. The observation of a retrolumbar subcutaneous ependymoma is reported with detail; this tumor exceptionally recognized by dermatologists must be included in the differential diagnosis of lumps arising in the retrolumbar-retrosacral area. The most peculiar feature was its development within a giant bathing-trunk nevocellular nevus; such a fascinating association of two neurectodermal defects, as far as known, is presented for the first time.

Extraspinal ependymoma in the sacrococcygeal region. A case report with ultrastructural, immunohistochemical and cytophotometric studies.Virchows Arch A Pathol Anat Histopathol. 1989;415(3):293-6.

We describe on a primary, subcutaneous sacrococcygeal ependymoma presenting in a young female patient. Detailed immunohistochemical and electron microscopic examinations were performed. Out of the 40 similar cases reported in literature this is the first in which the determination of DNA content was also used to predict biological behaviour. The tumour proved to be aneuploid with low proliferative capacity in spite of absent histological signs of malignancy. It is suggested that DNA determination may be helpful in establishing prognosis and that it may contribute to a better understanding of the biological behaviour of this tumour.