Rhabdoid meningioma of the tentorium with expression of desmin in a 12-year-old Turner syndrome patient

Abstract

Rhabdoid meningioma (RM) is a histological subtype of meningioma, associated with aggressive behaviour, characterized by patches or sheets of rhabdoid cells [2, 3, 4], similar to renal and extra-renal rhabdoid tumours [1, 7] and atypical teratoid/rhabdoid tumour (AT/RT) [6]. A RM with expression of desmin in the tentorium of a 12-year-old female, is described. To the best of our knowledge, this is the first case in a Turner syndrome patient. Clinical history consisted of several months of headache and right arm weakness. Neurological examination revealed right-sided hypotonia and hypostenia, tremor, imbalance, and ataxic gait. Physical examination showed short stature and delayed sexual development. On the basis of karyotype analysis, Turner syndrome was diagnosed. Computed tomography demonstrated a hyperdense mass in close relationship with the right cerebellar hemisphere, compressing the fourth ventricle. Magnetic resonance imaging (MRI) (Fig. 1a) demonstrated a T1 isointense, T2 hypointense tumour of the tentorium with extra-axial extension, both caudally and cranially. A ‘dural tail’ was seen medially. Necrotic portions were persistently hypointense after gadolinium administration. No brain or spinal metastasis were observed. The patient underwent a parieto-occipital craniotomy. The tumour was located in the posterior fossa, arising from the dura of the inferior surface of the tentorium, and extending into the supratentorial region. As the tumour was attached to the transverse sinus, only a subtotal resection was achievable. A minimal residual tumour, not demonstrated by post-operative neuroimaging, was left. Abdominal ultrasonography and chest X-ray were normal. After diagnosis the patient received local radiotherapy and hydroxyurea chemotherapy. MRI at 20 months was negative. Microscopic examination disclosed a highly cellular tumour entirely composed of sheets of large oval cells with eosinophilic cytoplasm, containing globular eosinophilic inclusions, and eccentric nuclei. Mitotic index was high (12/10 high-power field) (Fig. 1b). Multiple foci of necrosis were seen. Meningothelial lobules, whorls, and psammoma bodies were absent. Brain invasion was not observed. Tumour cells showed strong immunoreactivity for vimentin and focal membrane staining for epithelial membrane antigen (EMA) (Fig. 1c); the inclusions were immunoreactive for desmin (Fig. 1d). Tumour cells were negative for smooth muscle actin, muscle specific actin, MyoD1, myogenin, S-100 protein, and CD34. MIB1 labelling index was 15%. The coding sequences of hSNF5/INI1 and NF2 genes were screened by single-strand conformation polymorphism. The microsatellite markers (D22S1685D22S1553) on 22q11.23, near the hSNF5/INI1 locus, were analysed. No aberrant migration pattern of INI1 gene or loss of heterozygosity of INI1 locus were found. A deletion of exon 9 of the NF2 gene was detected. The first two authors contributed equally.