Cholesterol granuloma of the cerebello-pontine angle

Anterior tentorium-based epidermoid tumours: Results of radical surgical treatment in 96 cases

A retrospective analysis of 96 surgically treated tentorium and anterior tentorial hiatus-based epidermoid tumours from 1997 - 2004 is presented. The most prominent symptoms were headache (53.1%) and ataxia (44.8%). The average tumour size was 4.4 cm. Surgical approaches included posterior cranial fossa route (85 cases), basal subtemporal middle fossa route (9 cases) and combined posterior fossa and subtemporal routes in two cases. Total tumour resection was performed in 46 patients. Eight and four patients developed transient and sustained postoperative neurological deficits respectively. There was mortality in two patients. There was non-symptomatic recurrence of the tumour in two cases. Ninety-four patients are leading active functional lives. Radical and safe resection of anterior tentorium-based epidermoid tumours is associated with symptomatic relief and lasting cure. Extensive drilling of the petrous bone can be avoided. Gentle dissection of the tumour and capsule from the critical neurovascular structures can limit post-operative morbidity.

Cholesterol granuloma of the lateral ventricle. Case report

Cholesterol granulomas (CGs) are benign lesions resulting from an inflammatory reaction to cholesterol and hemosiderin. These masses most often arise within the temporal bone or nasal sinuses; intracerebral CGs are extremely rare. In this report the authors present an unusual case of a CG arising within the lateral ventricle. The patient presented with transient hemiparesis and numbness. Computed tomography and magnetic resonance imaging demonstrated a cystic partially enhancing midline mass within the right lateral ventricle, expanding the ventricle and displacing the septum pellucidum. The patient underwent an interhemispheric, transcallosal resection of the lesion. Microscopic examination revealed a granulomatous inflammatory lesion containing cholesterol clefts, macrophages, and hemosiderin. Embedded within the granulomatous response were foci of tiny cystlike structures lined by nonciliated flattened cuboidal epithelium, consistent with the diagnosis of CG. To the authors' knowledge this is the first reported case of CG presenting as an intraventricular mass. The origin of this lesion is unclear, but it may relate to prior traumatic brain injury. The authors describe the presentation, imaging findings, histopathological characteristics, and surgical treatment of this rare lesion and related pathological entities.

Differenzialdiagnose von Raumforderungen im Kleinhirnbr�ckenwinkel

Most of the space demands in the cerebellopontine angle lie extra-axially. Important structures run within the cisterns of the cerebellopontine angle, such as the trigeminal, facial and vestibulocochlear nerves as well as the anterior inferior and posterior inferior cerebellar arteries and the veins which lead to the petrosal sinus. The most common space demands are caused by acoustic neuromas, meningeomas, vascular ectasia and aneurysms. Less common are epidermoid and other schwannomas as well as metastases, paragangliomas and arachnoidal cysts. Intra-axial tumours in the area of the cerebellopontine angle include the medulloblastoma, astrocytoma and the ependymoma, which occurs predominantly in children, in addition to the uncommon choroid plexus papilloma. Nearby, there are also space demands around the petrous bone, such as cholesterol granuloma, malignant otitis media, paraganglioma and metastases. For differential diagnosis, an understanding of the space requirements of the tumours in the cerebellopontine angle is needed in addition to knowledge of the anatomical structures.

Congenital cholesteatoma and cholesterol granuloma of the temporal bone: role of magnetic resonance imaging

Magnetic resonance imaging (MRI) can be of significant benefit in characterizing expansile lesions of the petrous apex. MRI can be of particular help in distinguishing congenital cholesteatoma from cholesterol granuloma. Furthermore, with the advent of faster high-resolution scanning techniques, MRI can define precise spatial relationships of these masses with the middle and inner ear structures, internal carotid artery, jugular vein, and other structures of the skull base. MRI scanning is sensitive in detecting intracranial extension of these masses. MR angiography can provide additional information regarding the relationship of these masses with adjacent vascular structures and confirm patency of the adjacent vessels. In the postoperative period, MR scanning can help evaluate for complete removal, complication, recurrence, or formation of complicating granulation tissue.

The supracondylar approach to the jugular tubercle and hypoglossal canal

BACKGROUND

Circumscribed lesions of the hypoglossal canal and of the jugular tubercle still remain a surgical challenge. So far, transpetrosal, transcondylar suboccipital, and extreme lateral approaches have been used to access this region. These surgical procedures bear a high risk for neurological deficits. Therefore, we introduce a new minimally invasive extradural approach to the hypoglossal canal that also allows access to the lateral aspects of the jugular tubercle.

METHODS

After a paramedian retromastoid skin incision, a basal suboccipital craniectomy lateral to the foramen magnum toward the jugular tubercle is performed. With this approach the occipital condyle and the lateral osseous circumference of the foramen magnum are preserved. Drilling extradurally, the dorsal parts of the jugular tubercle are removed. The exposure is extended downward to the posterior margins of the hypoglossal canal and laterally to the jugular bulb, enabling a minimally invasive exposure of the hypoglossal canal, the lateral aspects of the jugular tubercle, and medial aspects of the jugular bulb.

RESULTS

Using this supracondylar approach, surgical interventions were performed in three patients suffering from a hypoglossal neurinoma, a cholesterol granuloma extending into the jugular tubercle, and a cyst of the hypoglossal canal, respectively. No additional postoperative neurological deficits were seen.

CONCLUSIONS

The supracondylar approach seems to be useful to gain access to benign lesions of the hypoglossal canal and of the jugular tubercle to decompress tumors or cysts. In contrast to previously reported techniques this approach has a low risk of morbidity. The surgical field, however, is restricted laterally by the jugular bulb, medially and basally by the residual occipital condyle and dorsally by the dura. Therefore, this approach is useful to remove small lesions or to perform extended biopsies. Radical removal of large tumors seems to be problematic using this approach.

Cholesterol granuloma of the orbit--pathogenesis and surgical management

BACKGROUND

Cholesterol granuloma of the orbit is a rare entity, and its pathogenesis is still poorly understood. We report on 6 cases including one patient who had been examined by X-ray prior to the tumor's clinical manifestation.

PATIENT DATA

All tumors were located in the superior temporal orbit. Histologically, they revealed the typical features of a cholesterol granuloma without any epithelial elements. They infiltrated the bone but left the soft tissues largely intact. Complete surgical removal of the granulomatous mass was attempted in each case, and particular attention was given to thorough abrasion of the bone. Only 2 patients reported a previous trauma. In one of them, retrospective evaluation of the X-ray scan taken a few hours after his accident revealed no definite changes in the orbital bone at the site of the future tumor. The only recurrence developed in a patient in whom the bony base of the tumor had not been drilled out completely.

CONCLUSIONS

The origin of orbital cholesterol granuloma remains unknown. According to our data and those available in the literature, trauma is not a precondition but may accelerate growth. Some non-epithelial malformation in the bone, with a predelection in the temporal upper quadrant, might be the origin. To prevent a recurrence it appears essential to totally erase the tumor from its bony bed.

Cholesterol granuloma in the middle cranial fossa: report of two cases

We report two cases of cholesterol granuloma in the middle cranial fossa. On CT the lesions appeared as a nonspecific, nonenhancing soft-tissue mass with bone erosion. On MRI they were seen as areas of high signal intensity surrounded by a low-intensity peripheral zone on both T1- and T2-weighted images. Cholesterol granuloma is thought to occur when pneumatised cells in the temporal bone become obstructed. Although this lesion usually occurs in the petrous bone, it can extend to the middle cranial fossa. The diagnosis and surgical management are discussed.