Tentorial Angioleiomyoma: A Rare Neurosurgical Entity. Case Report and Review of the Literature

Angioleiomyoma (ALM) is a soft tissue neoplasm rarely described in the intracranial site. Because of their uncommon presentation, atypical neuroradiologic and pathologic features, ALMs are often misdiagnosed.

We describe the neuroradiologic, clinical, and pathologic data of a 37-year-old male patient suffering from a tentorial ALM. He was admitted at our hospital because of a posterior cranial fossa mass. Magnetic resonance imaging (MRI) showed a left tentorial tumor, hypointense on T1-weighted sequences, with heterogeneous contrast enhancement after gadolinium injection ("salt-and-pepper" fashion) and slightly hyperintense signal on T2-weighted sequence. After surgery, pathological examination showed a tumor composed of several thick-walled blood vessels mixed with a population of deeply eosinophilic spindle-shaped smooth muscle cells arranged in bundles. Necrosis was absent. Neither cellular pleomorphism nor mitoses were detected. Immuno-histochemical analysis confirmed the smooth muscle phenotype of the spindle cell component: diffuse and strong positivity for alpha-smooth muscle actin, desmin, and h-caldesmon. Based on both morphologic and immunohistochemical findings, a diagnosis of primary intracranial ALM was rendered.

We add to the literature the tenth case of this exceedingly rare tumor and submit that ALM should be suspected when a tentorial mass with a "flame-like" time-dependent pattern of contrast enhancement on MRI, a "salt-and-pepper" post-contrast appearance on MRI T1-weighted sequences, and a relation with large intracranial feeding vessels are present.