Lateral sellar angiolipoma: a tumor illustrative of the extradural compartment of the neural axis.

Angiolipomas are rare tumors of the CNS that most frequently develop in the orbit, the cavernous space, and the epidural space of the spine. The authors report the case of a patient who presented with an angiolipoma of the cavernous space. Using data from the published literature and an experimental anatomical approach, they demonstrate that the cavernous space contains adipose tissue. Consequently, they suggest that angiolipomas constitute a characteristic tumor illustrating the interperiosteo-dural concept. The authors report the clinical, radiological, and histological data of a patient who presented with a tumor of the cavernous space. In addition, they prepared 2 encephalic extremities (4 cavernous spaces) using a special anatomical preparation consisting of an injection of colored neoprene latex followed by a 6-month immersion in a formaldehyde solution enriched with hydrogen peroxide to soften the bone structures (coronal sections) while leaving the fat in the cavernous space intact. This case report corroborates previously published clinical data and shows that the tumor was a hamartoma comprising mature fat cells associated with vascular proliferation. The tumor developed in the cavernous space, which is an interperiosteo-dural space extending from the sphenoid periosteum (osteoperiosteal layer) to the superior and lateral walls of the cavernous space (encephalic layer). This space represents an anatomical continuum extending from the coccyx to the orbit: the interperiosteo-dural concept. It contains fat tissue that is abundant at the level of the orbit and the epidural spinal space and sparser at the level of the cavernous spaces, as was shown in our anatomical study. The authors suggest that angiolipomas represent a characteristic tumor that illustrates the interperiosteo-dural concept because they essentially develop in the fat tissue contained in these spaces.