Meningeal Rosai-Dorfman disease mimicking meningioma.

Rosai-Dorfman disease of the central nervous system is extremely rare and difficult to diagnose also for pathologists. We describe three unusual cases of meningeal Rosai-Dorfman disease and illustrate the difficulties of preoperative and pathological diagnosis. We retrospectively analyzed three patients who underwent surgery for a suspected meningioma for whom the final diagnosis was Rosai-Dorfman disease of the central nervous system. Pathological initial diagnosis was schwannoma, lymphoplasmacyte-rich meningioma, or inflammatory tumor, but final diagnosis in all cases was Rosai-Dorfman disease. These cases underline the preoperative and pathological difficulties of such diagnosis. Pathologists and physicians should be aware of the occurrence of such rare localization of this disease and should think about this differential diagnosis in lymphocyte-rich meningeal tumors mimicking, clinically and radiologically, a meningioma. Communication of significant previous medical history to pathologists and careful examination of slides with appropriate medical history and the use of S100 antibody in the diagnosis of meningeal tumors mimicking Rosai-Dorfman disease could lower the rate of misdiagnosis.

Multidisciplinary management of giant functional petrous bone paraganglioma.

Giant and functional paragangliomas of the skull base are rare. Their endocrinological and surgical management is challenging. We report the case of an aggressive giant noradrenalin-secreting paraganglioma of the right temporal bone. Three procedures of embolisation were performed. The second one was complicated by a hypertensive crisis due to catecholamine release. The tumour was resected via a widened transcochlear approach. Tumour residue was treated by gamma knife radiosurgery, without additional growth at the last follow-up. This case illustrates the interest of multidisciplinary management of giant skull base paragangliomas.

Morphological changes of vestibular schwannomas after radiosurgical treatment: pitfalls and diagnosis of failure.

RATIONALE: Evaluate the morphological changes following radiosurgery in order to better define failure parameters. METHODS: 332 non-neurofibromatosis type 2 vestibular schwannomas not previously treated surgically or radiosurgically were subjected to Gamma Knife radiosurgery between 1992 and 2004 at the Gamma Knife Center in Marseille with at least three sequential MRI scans after radiosurgery. Five length measurements were systematically obtained. RESULTS: Mean follow-up was 4.6 years. Transient loss of contrast enhancement appeared in 213 patients (68%). Significant increase was present at 6 months in 178 patients. In 74 patients, the volume at 3 years was still higher than on the day of radiosurgery but remained stable. Failure occurred in 16 patients. Most showed progressive growth at all MRI controls after radiosurgery but late failure after initial response was possible. CONCLUSIONS: Sequential MRI scans after radiosurgery are necessary. A progressive and continuous growth at 3 years is essential to make diagnosis of failure.

Modern management of vestibular schwannomas.

Within the last 3 decades, microsurgery and stereotactic radiosurgery (SRS) have become well-established management options for vestibular schwannomas (VSs). Advancement in the management of VSs can be separated into three periods: the microsurgical pioneer period, the demonstration of SRS as a first-line therapy for small and medium-sized VSs, and currently, a period of SRS maturity based on a large worldwide patient accrual. The Marseille SRS experience includes 1,500 patients, with 1,000 patients having follow-up longer than 3 years. A long-term tumor control rate of 97%, transient facial palsy lower than 1%, and a probability of functional hearing preservation between 50 and 95% was achieved in this large series of patients treated with state-of-the-art SRS.

Functional outcome after gamma knife surgery or microsurgery for vestibular schwannomas.

OBJECT: Microsurgical excision is an established treatment for vestibular schwannoma (VS). In 1992 the authors used a patient questionnaire to evaluate the functional outcome and quality of life in a series of 224 consecutive patients. In addition, starting with gamma knife surgery (GKS) in 1992, the authors decided to use the same methodology to evaluate prospectively the results of this modality to compare the two alternatives. METHODS: Among the 500 patients who were included prospectively, the authors only evaluated patients in whom GKS was the primary treatment for unilateral VS. Four years of follow up was available for the first 104 consecutive patients. Statistical analysis of the GKS and microsurgery populations has shown that only a comparison of Stage II and III (according to the Koos classification) was meaningful in terms of group size and preoperative risk factor distribution. Objective results and questionnaire answers from the first 97 consecutive patients were compared with the 110 patients in the microsurgery group who fulfilled the inclusion criteria. Questionnaire answers indicated that 100% of patients who underwent GKS compared with 63% of patients who underwent microsurgery had no new facial motor disturbance. Forty-nine percent of patients who underwent GKS (17% in the microsurgery study) had no ocular symptoms, and 91% of patients treated with GKS (61% in the microsurgery study) had no functional deterioration after treatment. The mean hospitalization stay was 3 days after GKS and 23 days after microsurgery. All the patients who underwent GKS who had been employed, except one, had kept the same professional activity (56% in the microsurgery study). The mean time away from work was 7 days for GKS (130 days in the microsurgery study). Among patients whose preoperative hearing level was Class 1 according to the Gardner and Robertson scale, 70% preserved functional hearing after GKS (Class 1 or 2) compared with only 37.5% in the microsurgery group. CONCLUSIONS: Functional side effects happen during the first 2 years after radiosurgery. Findings after 4 years of follow up indicated that GKS provided better functional outcomes than microsurgery in this patient series.