Myxoid (metaplastic) meningioma is a rare WHO Grade I meningioma subtype arising from the leptomeninges. It has unique Alcian blue stromal staining and distinctive cellular interdigitations, junctional complexes, and nucleolar pseudoinclusions on ultrastructural pathology that help to distinguish it from other meningioma variants. The authors describe the case of a rare left middle fossa, extraaxial myxoid meningioma in a 50-year-old woman to emphasize the important histological characteristics and observations essential for making a precise diagnosis. To their knowledge this is the seventh reported case of a myxoid meningioma in the literature and the sixth case in an adult; however, it is the first reported instance of myxoid meningioma in a patient presenting with intratumoral hemorrhage.
Khaled M. Krisht, Tamer Altay and William T. Couldwell
Christian A. Bowers, Tamer Altay and William T. Couldwell
Although the transcranial route (TCR) has been the traditional approach for removing tuberculum sellae meningiomas (TSMs), the use of the microscopic and/or more recently the endoscopic transsphenoidal approach (ETSA) has gained acceptance for selected cases. In this study, the authors present their experience with the ETSA and the TCR and examine the criteria most important for deciding the optimal approach in a particular case.
The authors retrospectively reviewed recent cases of TSMs treated surgically by the senior author via either the TCR or the ETSA or both. Demographic information, clinical presentation, and clinical and radiological outcomes of the patients were evaluated.
Twenty-seven patients underwent removal of a TSM during a recent period. Gross-total or near-total resection was achieved in 20 (91%) of 22 patients who underwent resection via the TCR and in 3 (60%) of 5 patients who underwent the ETSA. Among the patients in whom gross- or near-total resection was achieved, recurrence was observed in only 1 patient, whose tumor was removed via the ETSA.
In the majority of patients, the TCR provided complete resection of the tumor without compromising the safety of the procedure. In select cases of tumors with a reasonable size and location (midline and/or extending into the sphenoid sinus) as well as no involvement of inaccessible neurovascular and bony elements via this approach, the ETSA could also be a viable option.
Michael L. Mumert, Tamer Altay, Clough Shelton, H. Ric Harnsberger and William T. Couldwell
Ganglion cysts arising from the temporomandibular joint are rare entities that often present with swelling and minimal to no pain in the preauricular region. To the authors' knowledge, a temporomandibular joint ganglion cyst occurring with acute facial nerve palsy and intracranial extension has never been reported. The patient in the current case initially underwent treatment for Bell palsy and then draining of the cyst at an outside hospital with no relief of symptoms. Repeat MR imaging showed an increase in the size of the cystic, enhancing, middle fossa lesion measuring 4 cm. Resection of the lesion was undertaken using a middle fossa approach. After a satisfactory surgical decompression, the patient demonstrated a significant recovery in her facial palsy over a 3-month period of time. This case presents new clinical and radiographic findings associated with these lesions.
Tamer Altay, Bhupendra C. K. Patel and William T. Couldwell
Lesions of the cavernous sinus remain a technical challenge. The most common surgical approaches involve some variation of the standard frontotemporal craniotomy. Here, the authors describe a surgical approach to access the cavernous sinus that involves the removal of the lateral orbital wall.
To achieve exposure of the cavernous sinus, a lateral canthal incision is performed, and the lateral orbital rim and anterior lateral wall are removed, for later replacement at closure. The posterior lateral orbital wall is removed to the region of the superior and inferior orbital fissures. With reflection of the dural covering of the lateral cavernous sinus and removal of the anterior clinoid process, the cavernous sinus is exposed.
Exposure and details of the procedure were derived from anatomical study in cadavers. After the approach, with removal of the anterior clinoid process, the entire cavernous sinus from the superior orbital fissure anteriorly to the Meckel cave posteriorly is exposed. More exposure to the lateral middle fossa, foramen spinosum, and petrous carotid artery is obtained by further removal of the lateral sphenoid wing. An illustrative case example for approaching a cavernous sinus meningioma is presented.
The translateral orbital wall approach provides a simple, rapid approach for lesions with primary or secondary involvement of the cavernous sinus. Advantages of this simple, extradural approach include the lack of brain retraction and no interruption of the temporalis muscle.