Angioleiomyoma, a rare intracranial tumor: 3 case report and a literature review

Abstract

Three cases of intracranial angioleiomyoma (ALM) in our neurosurgery center are reported in detail. ALM is a benign soft tissue tumor comprised of mature smooth muscle cells and a prominent vascular component, which is extremely rare as a primary intracranial lesion. Altogether, only 12 cases were recorded in the literature to date, to the best of our knowledge. Case 1 is the second report of intra-sella ALM, a 51-year-old woman presented with visual deterioration for 2 months. An MRI showed an intra-sella 3-cm tumor, partially flame-like, enhanced with gadolinium. Using microscopic endonasal transsphenoidal approach, the tumor was completely resected with great difficulty. At 11 days post-surgery, she died of a sudden catastrophic nasal hemorrhage. An angiography revealed a pseudo-aneurysm of ICA (internal carotid artery). Case 2 is a 49-year-old man who presented with weakness of the lower limbs for 1 year. A large subtentorial mass was found affixed to the torcular and straight sinus, which was partially flame-like, dramatically enhanced as in case 1. Case 3 is that of a 77-year-old man. An ALM mass was revealed in the diploe of left temporal bone, and had eroded the inner table. Immunohistochemical workup confirmed the diagnosis of angioleiomyoma in all 3 cases. The radiology, operation, and complication of surgery in each case were discussed. In conclusion, intracranial ALMs are extremely rare, usually located ex-neuro axis (such as in our cases), in the sella, in posterior fossa, or in the skull. Magnetic resonance imaging (MRI) revealed a special feature of flame-like partial enhancement that may be helpful to distinguish ALM from pituitary tumors or meningiomas, and should result in the consideration of this rare tumor entity early on in the diagnostic process. A definitive diagnosis depends on histological analyses. The resection of ALM in certain locations is difficult and risky because of the rich blood supply.

Figure 1

MRI scans for cases 1-3. Case 1: (A) preoperative MRI T2-w FLAIR, (B) T1-w MRI with contrast revealed a partially enhanced lesion in the sella, adjacent to the cavernous sinus, (C) postoperative MRI with contrast. Case 2: (D) preoperative MRI T1-w revealed a large subtentorial lesion, the cerebellum and brainstem were obviously compressed forward and downward, (E) MRI with contrast revealed the lesion was partially flame-like enhanced, (F) postoperative MRI with contrast one year later. Case 3: (G) preoperative T2-w MRI revealed a lesion in diploic space of the left temporal skull vault which had invaded inward, (H) MRI with contrast showed the tumor was enhanced, (I) postoperative MRI with contrast one year later. The arrows indicate the tumors. MRI (Magnetic resonance imaging), FLAIR (fluid-attenuated inversion recovery).

Figure 2

Photomicrographs of the pathological specimen. Case 1: (A) 40 × magnification photomicrograph delineating the overall view, hematoxylin and eosin (H&E). Loose arraying spindle cells riddled with irregular vascular spaces, some containing blood. (B) 40 × magnification immunohistochemistry of smooth muscle actin (SMA), the spindle cells were strongly positive for SMA as shown by the brown color. Case 2: (C) 40 × magnification photomicrograph, H&E, showed the interface between the tumor and dura. (D) 40 × magnification with immunostaining for SMA, whorls of spindle cells were positive for SMA, showing brown. Case 3: (E) 100 × magnification photomicrograph (H&E) illustrated that the tumor was composed of smooth muscle cells and vessels. (F) 40 × magnification photomicrograph of the immunohistochemistry of CD34 showed a selected stain of the single layer of endothelium lining the channels, shown by the brown color. The arrow points to the adjacent dura matter.

Figure 3

The digital subtractive angiography (DSA) of Case 1 after a lethal nasal hemorrhage. (A) The 3-dimension reconstruction DSA showed the pseudo-aneurysm (the arrow) at the cavernous segment of the right internal carotid artery (ICA), (B) the DSA roadmap when the second bleeding occurred.