RESUMEN
AIMS: Clear cell meningioma (CCM) is a rare subtype of meningioma and shows not only unusual histology, but also unique clinical features. Recently, SMARCE1 mutations have been shown to cause spinal and cranial CCMs. We present 12 cases which were diagnosed with CCM in a single institution between 1997 and 2014, and investigate their SMARCE1 mutation status. METHODS AND RESULTS: To investigate the SMARCE1 mutation status of these tumours, we used a combination of Sanger sequencing and multiplex ligation-dependent probe amplification analysis and also performed SMARCE1 immunohistochemical staining. We found both SMARCE1 mutational hits, including novel SMARCE1 mutations, in six of eight tested patients. Immunohistochemical analysis showed loss of SMARCE1 protein staining in all but two cases. Two individuals who were diagnosed originally with CCM were negative for SMARCE1 mutations, but tested positive for NF2 mutations. As a result, these two tumours were re-analysed and eventually reclassified, as a microcystic and a mixed pattern of meningothelial meningioma with focal clear cell areas, respectively. CONCLUSIONS: These results expand the spectrum of pathogenic variants in SMARCE1 and show that mutation screening can help to facilitate meningioma classification. This may have implications for prognosis and future clinical management of patients, as CCMs are classed as grade II tumours, while microcystic and meningothelial meningiomas are classed as grade I.
Asunto(s)
Proteínas Cromosómicas no Histona/genética , Proteínas de Unión al ADN/genética , Neoplasias Meníngeas/clasificación , Neoplasias Meníngeas/genética , Meningioma/clasificación , Meningioma/genética , Adolescente , Adulto , Niño , Análisis Mutacional de ADN , Femenino , Humanos , Inmunohistoquímica , Masculino , Neoplasias Meníngeas/patología , Meningioma/patología , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa Multiplex , Adulto JovenRESUMEN
Ganglioneuroblastic transformation in olfactory neuroblastoma (ONB) is an exceptionally rare phenomenon. We document the case of a patient with a poorly differentiated sinonasal malignancy that recurred following treatment with chemoradiotherapy and showed ganglioneuroblastic transformation. Although the index tumour showed neuroendocrine differentiation, it did not have the typical clinico-pathological features associated with ONB. We highlight the diagnostic difficulties in establishing an accurate diagnosis for undifferentiated sinonasal tumours and present evidence that the index tumour was an ONB. The current report is only the third case of ONB showing complete ganglioneuroblastic transformation.