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

A 51-year-old woman presented to our neurosurgery center with a two-month long blurry of the right eye, which gradually worsened, eventually losing vision in the eye 20 days before admission. A neurological examination revealed that the sight of the right eye was 0.03, with bilateral temporal hemianopsia. There were no other remarkable signs. An endocrinological evaluation showed only a low value of blood cortisol. T1-weighted (T1-w) MRI scans revealed an iso-signal intra-sella tumor sized 3.0 × 2.5 × 2.5 cm, close to the medial part of the right cavernous sinus, with distinctive partial enhancement after a gadolinium injection, which arose from the right cavernous sinus, flame-like in shape, with bush-like edge (Figure 1B). T2-fluid-attenuated inversion recovery-weighted sequences (T2-FLAIR) showed a homogeneous hyper-signal tumor (Figure 1A). The sella fossa was obviously enlarged and the tumor had invaded into the sphenoid sinus. It was considered to be a non-functional pituitary tumor.

A microscopic endonasal transsphenoidal approach was used for surgical resection. After dural opening, a solid, tenacious, purple mass was found, sticking firmly with surrounding structures, with abundant blood supply. The tumor was extremely difficult to manipulate and had to be excised en bloc to avoid bleeding. It was completely excised after hours of careful separation between the tumor capsule and the cavernous sinus. The removed tissue was dark purple, shrinking, sponge-like, and approximately 2.5 cm in size. After common hemostasis, the wound was sealed with gel foam and glue. Microscopically, the lesion was essentially composed of spindle shaped smooth muscle cells and blood vessels with thick walls devoid of elastic lamina (Figure 2A). The vessel lumen was slit-like and the inner wall was lined with monolayer endothelial cells, and the smooth muscles of the vascular wall intermingled with the smooth muscle cells between the vessels. No mitoses were found. Immunohistochemistry revealed that the spindle cells were positive for vimentin (Vim) and smooth muscle actin (SMA) (Figure 2B), and negative for glial fibrillary acidic protein (GFAP) and neurofilament (NF). The endothelial cells were positive for CD34. The tumor was identified as ALM. The patient had no complaints postoperatively, except for a slight headache. The sight of her right eye promoted obviously two days after surgery. An MRI scan demonstrated a total resection (Figure 1C) without any bleeding. At 11 days after the operation, she complained of a decreasing of hearing in her left ear and a little nose discharge, although the headache diminished. An ear-nose-throat inspection was recommended. However, an emergent incident happened while she was under nasal endoscope, as the surgical area suffered a sudden high pressure expulsion of blood. After 10 minutes, 1200 ml blood had been lost and she lost consciousness due to acute shock. Her nasal cavity was packed with gauze and the bleeding temporarily stopped. A cerebral DSA (Digital Subtraction Angiography) was immediately performed. A pseudo-aneurysm of the left internal carotid artery (ICA) cavernous segment was revealed (Figure 3A arrow). When we tried to embolize it, a second bleeding occurred (Figure 3B), invading into cranial cavity, and she fell into deep coma. We immediately embolized the left ICA and performed vital resuscitation. Although supported by mechanical ventilation and circulation, she died one day later.

A 49-year-old man had a one-year history of weakness in the lower limbs, walking instability, sporadic falling down, dizziness, nausea, and vomiting. His neurological examination revealed a tongue slant to right, a positive Romberg sign, and muscle strength grade IV in both lower extremities.

An MRI scan revealed a large sub-tentorium lesion in the posterior fossa. The mass was sized 4.2 × 4.6 × 5.7 cm, affixed to the straight sinus and torcular, compressing forward. There was great displacement of the cerebellum, brain stem, and the fourth ventricle. The cerebella tonsillar had herniated into the foramen magnum. Supra-tentorial ventricular dilation was presented due to obstructive hydrocephalus. A T1-w MRI showed a slightly hypo-signal homogeneous tumor (Figure 1D), and T2-w and FLAIR(fluid-attenuated inversion recovery) scans revealed even hyper-signal. With gadolinium contrast, the lesion was obviously unevenly or partially enhanced, the enhancing was progressive from posterior to anterior, flame-like, with an irregular flocky twiggy edge, and the front part of the lesion was hardly enhanced (Figure 1E). The differential diagnosis included hemangioblastoma and meningioma.

A midline suboccipital craniotomy was performed. The tumor was found to be affixed to the torcular and the posterior part of the straight sinus, closely adhered with the dura. It was a purple color, tough, had a clear boundary, and an abundant blood supply. The tumor was removed piece by piece under a microscope. Most of the lesion was freed from the dura, except a minimal piece that could not be removed safely from the torcular, therefore a subtotal resection was made. Approximately 620 ml blood was lost altogether. The pathology features mimic those in case 1 (Figure 2C). The smooth muscle cells were positive for SMA (Figure 2D) and Vim, and the inner-vessel endothelial cells were positive for CD34, negative for epithelial membrane antigen (EMA), and negative for inhibin-a. The patient recovered without incident and an MRI scan showed a satisfying resection (Figure 3B). On a follow-up CT scan five months later and a further follow-up MRI scan one year later (Figure 1F), no recurrence was demonstrated. The patient’s legs resumed normal strength and recovered well, except for some walking instability.

A 77-year-old man suffered from an intermittent headache for five months. His neurological physical examination was unremarkable. T1-w MRI scans revealed an iso-signal tumor arising from the diploic space of the left temporal skull vault, invading inward to temporal lobe, sized 1.6 × 3.1 × 3.9 cm. T2-w and FLAIR scans showed a hyper-signal lesion (Figure 1G). Obvious enhancement was seen after a gadolinium injection (Figure 1H). There was no enhancement of the dura or ‘dura tail’. The diploic angioma, meningioma, fibrosarcoma, and aneurysmal bone cyst were considered.

A craniotomy was performed. The cranial outer table was intact, the inner lamina and diploe were eroded with hyperostosis around. The tumor was a dark reddish hue with a rich blood supply, adhered to the dura. The whole tumor was removed. After autoclaving, the bone flap was returned and fixed in the original place. A histological analysis demonstrated typical elongated smooth muscle cells and dilated irregular vascular channels (Figure 2E). The smooth muscle cells were immunoreactive for SMA, actin, and Vim. The intra-vessel endothelial cells were positive for CD34 (Figure 2F). The patient recovered rapidly. At 12-month follow-up, MRI scans were performed, there was no tumor recurrence (Figure 1I).