Study design: Cystic dilatation of the fifth ventricle on its own is an extremely rare pathological event in adults whose pathogenesis is uncertain. The authors describe a personal case of 'fifth ventricle' and review the pertinent literature. Objective: To emphasize the importance of including the fifth ventricle in differential diagnosis of lesions of the conus medullaris to ensure proper treatment. Setting: Italy. Methods: A 30-year-old woman was referred to us for recurrent low back pain. The patient was assessed by clinical, electrophysiological (motor evoked potential, somatosensorial evoked potential and electromyography of the perineal and lower limb muscles) and urodynamic investigations as well as a magnetic resonance imaging (MRI) of the lumbar-sacral segment with and without gadolinium enhancement, subsequently extended to the entire vertebral column and brain. Follow-up consisted of periodic clinical evaluation and lumbar-sacral MRI after 1 and 2 years. Results: General physical examination, electrophysiological and urodynamic investigations were all negative, confirming the subjective nature of the patient's symptoms. Lumbar-sacral MRI demonstrated the presence of a cyst lesion containing cerebrospinal fluid (CSF), which did not enhance after gadolinium, compatible with the diagnosis of the terminal ventricle. By extending the MRI investigation to the entire vertebral column and brain, it was possible to exclude an association with other malformations of the central nervous system. Clinical and radiological follow-up confirmed the nonevolutive nature of the lesion 1 and 2 years later. Conclusions: The lack of clinical symptoms and the stability of the radiological situation at 1 and 2 years follow-up motivated our choice of conservative treatment.Spinal Cord (2005) 43, 381-384.

The schwannomas are benign tumors originating from Schwann cells which constitute the nerve sheath. The dorsal pigmented type of schwannomas is relatively rare (Goldstein in Am J Med Genet 86:62–65, 2004; Kurtkaya-Yapicier in Histol Histopathol 18(3):925–934, 2003). There are two distinct types of melanotic schwannoma: the sporadic melanotic schwannomas and the psammomatous melanotic schwannomas of Carney complex. We report a case of a patient harboring a right dorsal dumb-bell melanotic schwannoma and left adrenal mass. The patient underwent a surgical procedure for en bloc total removal of the mass by a posterior and anterior approach. Histopathological examination revealed the diagnosis of melanotic schwannoma. At present, we have no reliable marker of histopathological malignancy of melanotic schwannoma so the follow-up period ought to continue for a period of more than 5 years. As the total removal of the melanotic neurinomas is mandatory to prevent possible malignant transformation of the tumor recurrence or regrowth, we believe that the posterior and trans-thoracic approach are the most suitable one for the dorsal dumb-bell schwannoma.

The authors present a case of pseudoglandular schwannoma with immunohistochemical findings consistent with epithelial metaplasia. Pseudoglandular schwannoma is a rare morphological variant of benign schwannoma characterized by the presence of glandlike structures lined with Schwann cells. To the best of the authors' knowledge, this is only the fifth case of pseudoglandular schwannoma reported in the literature. Clinical, imaging, and pathological findings are described. The pathological findings were consistent with a pseudoglandular schwannoma composed of typical Schwann cells arranged in an Antoni B pattern, with numerous large pseudocystic spaces. Serial immunohistochemical studies of tissue sections revealed that the cells lining the pseudoglandular spaces were not only diffusely reactive for S100 protein, but also demonstrated focal positivity for epithelial membrane antigen and cytokeratins AE and AE3. The particular immunohistochemical features of incompletely differentiated Schwann cells in the present case give support to the metaplastic theory of the origin of glandlike structures in benign peripheral nerve sheath tumors.