Planum sphenoidale meningioma case series

A consecutive series of patients who were 18 years of age or older and underwent EEA for newly diagnosed grade I Planum sphenoidale meningioma (PS) meningiomas (PSMs) and TS meningiomas (TSMs) between October 2007 and May 2021 were included. The PS and TS were distinguished by drawing a line passing through the center of the TS and perpendicular to the PS on postcontrast T1-weighted MRI. Probabilistic heatmaps were created to display the actual distribution of tumor volumes. Tumor volume, extent of resection (EOR), visual outcome, and complications were assessed.

Results: The 47 tumors were distributed in a smooth continuum. Using an arbitrary definition, 24 (51%) were PSMs and 23 (49%) were TSMs. The mean volume of PSMs was 5.6 cm3 compared with 4.5 cm3 for TSMs. Canal invasion was present in 87.5% of PSMs and 52% of TSMs. GTR was achieved in 38 (84%) of 45 cases in which it was the goal, slightly less frequently for PSMs (78%) compared with TSMs (91%), although the difference was not significant. Th mean EOR was 99% ± 2% for PSMs and 98% ± 11% for TSMs. Neither the suprasellar notch angle nor the percentage of tumor above the PS impacted the rate of GTR. After a median follow-up of 28.5 months (range 0.1-131 months), there were 2 (5%) recurrences after GTR (n = 38) both of which occurred in patients with PSMs. Forty-two (89%) patients presented with preoperative impaired vision. Postoperative vision was stable or improved in 96% of patients with PSMs and 91% of patients with TSMs. CSF leakage occurred in 4 (16.6%) patients with a PSM, which resolved with only lumbar drainage, and in 1 (4.3%) patient with a TSM, which required reoperation.

Planum sphenoidale meningioma and tuberculum sellae meningioma arise in a smooth distribution, making the distinction arbitrary. Those classified as Planum sphenoidale meningioma were larger and more likely to invade the optic canals. The surgical outcome for both locations was similar, slightly favoring tuberculum sellae meningioma. The arbitrary distinction between planum sphenoidale meningioma and tuberculum sellae meningioma is less useful at predicting outcome than the lateral extent of the tumor, regardless of the site of origin ¹⁾.

Mortazavi et al., conducted a retrospective review of the patients who between 2005 and March 2015 underwent a craniotomy or endoscopic surgery for the resection of meningiomas involving the suprasellar region. Operative nuances of a modified frontotemporal craniotomy and orbital osteotomy technique for meningioma removal and reconstruction are described.

Twenty-seven patients were found to have tumors arising mainly from the planum sphenoidale or the tuberculum sellae; 25 underwent frontotemporal craniotomy and tumor removal with orbital osteotomy and bilateral optic canal decompression, and 2 patients underwent endonasal transphenoidal resection. The most common presenting symptom was visual disturbance (77%). Vision improved in 90% of those who presented with visual decline, and there was no permanent visual deterioration. Cerebrospinal fluid leak occurred in one of the 25 cranial cases (4%) and in 1 of 2 transphenoidal cases (50%), and in both cases it resolved with treatment. There was no surgical mortality.

An orbitotomy and early decompression of the involved optic canal are important for achieving gross total resection, maximizing visual improvement, and avoiding recurrence. The visual outcomes were excellent. A new classification system that can allow the comparison of different series and approaches and indicate cases that are more suitable for an endoscopic transsphenoidal approach is presented ²⁾.

In patients treated with endonasal endoscopic meningioma surgery. Sughrue et al., believe that very low rates of morbidity can be achieved in carefully selected patients, thus avoiding brain manipulation ³⁾.

7 PSMs (23.3%) of midline anterior skull base meningiomas ⁴⁾.

12 planum/jugum sphenoidale meningioma ⁵⁾.

Zygourakis et al., retrospectively identified 44 patients with planum/olfactory meningiomas treated at our institution from 1996 to 2006. We used univariate and multivariate regression models to analyze the effect of several magnetic resonance imaging characteristics (tumor volume, distance to optic chiasm, anterior cerebral artery encasement, paranasal sinus invasion, and sellar invasion) on preoperative symptoms and postoperative outcomes, including complication rate and tumor recurrence.

Only brain tumor volume (>42 cm(3)), but not distance to the optic chiasm, is independently associated with an increased likelihood of preoperative visual symptoms. Tumors with nasal sinus invasion are significantly more likely to cause postoperative surgical complications, and tumors with anterior cerebral artery encasement are associated with a greater likelihood of both postoperative complications and tumor recurrence.

Tumors larger than 3.4 cm in diameter and those whose posterior edge is within 6-8 mm of the optic chiasm should be recommended for early surgical intervention. In terms of predicting surgical complications, nasal sinus invasion and anterior cerebral artery encasement are associated with greater-risk profiles when surgery becomes necessary. Thus, it is prudent to take these specific variables into consideration when advising patients about the risks of observation and surgery for olfactory/planum meningiomas ⁶⁾.

Perera et al., retrospectively reviewed the clinical records of 17 patients with planum sphenoidale meningiomas who were admitted between 2004 and 2011. Patients had formal visual assessments (including Humphrey’s visual field testing) pre- and postoperatively.

The mean age at presentation was 62.3 years; there were 11 women and 6 men. The meningiomas ranged in diameter from 17 mm to 70 mm (mean diameter 37.2 mm). Twelve of the patients had neurosurgical intervention (seven of these had a pterional approach, three had a bicoronal frontal approach, and two had the tumor resected via the transglabellar frontal approach). Histological analysis showed nine of the cases were WHO grade I and the remaining three were grade II.

Ten of the patients demonstrated improvement in their visual acuity assessment, and four of the patients had no demonstrable visual impairment preoperatively.

Conclusions: Prevention of visual deterioration and/or improvement of visual function remain benefits that could be attained by resection of planum sphenoidale meningioma. Pre- and postoperative formal ophthalmological assessments should be an integral component in the management of these tumors.

A review propounds a strategy to secure visual acuity through operation. A total of eight cases are summarized. In five midline symmetrical meningiomas, the tumors compressed the nerves at the portion of the optic chiasma, causing a typical bitemporal hemianopsia. Four large tumors were resected by the frontobasal interhemispheric approach to minimize the intraoperative damage to the optic chiasma, and a small one was removed by the pterional approach. Visual disturbances were recovered immediately after the operation in all cases without any surgical complications. Three meningiomas were attached to the lateral part of the planum sphenoidale or tuberculum sellae. Although the sizes were relatively small in all cases, they caused ipsilateral severe visual loss by direct compression to optic nerves. MRI and three-dimensional CT angiography showed the tumor extension into the optic canal. The ipsilateral pterional approach was selected in these cases. To avoid additional nerve damage, we tried to reduce the tension of nerves which were compressed by the tumors. Uede et al., removed the anterior clinoid process and opened the optic canal before surgical manipulation of the tumor. In two cases, tumors severely compressed the optic nerves from the medial side, and nerves were stretched laterally. Great care was required to separate the optic nerves from tumors in those two cases. In contrast, the resection seemed to be very easy in one of the cases where the optic nerve was displaced infero-medially. Visual symptoms were improved in all cases, although one case became worse temporarily. Although planum sphenoidale and tuberculum sellae meningiomas are still troublesome, appropriate preoperative management would allow us to expect an excellent visual outcome. Especially, selection of the surgical approach should be based on the anatomical analysis of the nerve displacement ⁷⁾.

In this article 105 cases of meningiomas of the planum sphenoidale and tuberculum sellae are reviewed. In only five cases was the diagnosis made within three months of the onset of the symptoms ⁸⁾.

Meningiomas of the tuberculum sellae and planum sphenoidale. A review of 83 cases ⁹⁾.