Angioleiomyomas of the dura: Rare entities that lack KRIT1 mutations

Angioleiomyomas (ALMs) are cutaneous and soft tissue lesions usually seen in the lower extremities of middle-aged women. The lesions are nodular, mulberry like, and composed of vessels of varying size with abundant intervening smooth muscle; an arterial component is absent. Intracranial examples are exceedingly rare, with <10 cases reported to date, and are usually dural in location. We report the case of 2 young men with dural ALMs: one infratentorial and located near the incisura and the second falcine, posterior to the splenium. Both patients came from the same medium-size community in southern Colorado with a known high incidence of a Hispanic population at risk for familial cavernous cerebral hemangiomas (fCCMs). Both presented within a month of each other with greater than 8-year histories of headaches; preoperative and intraoperative diagnoses were cerebral cavernous malformation (CCM) or vascular meningioma. Histologically, both had discrete lesions composed of large cavernous channels lined by a single layer of cytologically bland endothelium and surrounded by mature, smooth muscle of varying thickness that was orderly near the lumen, more disorganized in intervening areas, and immunoreactive for smooth muscle actin (SMA), muscle-specific actin, and vimentin but not for desmin. Concentric whorls of SMA/CD34 cells were a distinctive feature. We posited that there might be a relationship between dural ALMs and CCMs and undertook polymerase chain reaction-based mutational analysis for the single common mutation seen in Hispanics with familial cavernous cerebral hemangiomas, that is, c.1363C>T KRIT1. Testing proved negative, despite the fact that 1 patient was of strong Hispanic heritage. We concluded that dural ALMs are easily clinically mistaken for CCMs or meningiomas but are not of similar histopathogenesis.