Solitary fibrous tumor of the tentorium cerebelli. Case report.

Solitary fibrous tumor (SFT) is a mesenchymal neoplasm that has been recognized to occur almost all along the organism. Since its description in 1996 at the meninges, a total of 59 cases of meningeal SFT have been reported. Different authors have emphasized the difficulties in the differential diagnosis with other more frequent meningeal neoplasms such as meningioma or hemangiopericytoma, as the clinico-radiological characteristics of this lesion seem to be non specific and the morphological features on pathological study may resemble other spindle cell neoplasms. The diffuse and strong reactivity for CD34 and the negativity for EMA and S-100 are data allowing the diagnosis of SFT. We report the case of a 50-year-old woman suffering from headache, in whom MRI study showed a tentorial lesion initially thought to be a meningioma. In spite of morphological similarities with a fibrous meningioma, inmunohistochemical study finally led to the diagnosis of SFT. As occurred in previous cases, the findings in our patient reflect the similarities in clinico-radiological and pathological characteristics between meningeal SFT and other spindle cell meningeal neoplasms, mainly fibrous meningioma. When a clear diagnosis cannot be done based on typical findings on conventional hematoxylin-eosin study, inmunohistochemical study should be performed in meningeal spindle cell lesions to exclude SFT.