Planum Sphenoidale Meningioma

68M with headache • Xray of the Week

Figure 1. What is the important finding on these images.

Figure 2. CT of a planum sphenoidale meningioma.

A. Axial non contrast CT showing subtle density in midline frontal region (red arrows).

B. Coronal non contrast CT showing subtle density in midline frontal region (red arrows).

C. Axial CT with contrast showing enhancing midline mass (green arrows).

D. Coronal CT with contrast showing enhancing midline mass with a broad base along the planum sphenoidale (green arrows).

Introduction:

Meningiomas are extra-cranial tumors which are attached to the dura in most cases (1, 4). Around 5-10% of meningiomas are suprasellar, which are subclassified as arising from the planum sphenoidale, tuberculum sellae, diaphragma sellae, and anterior clinoid process (2). Planum sphenoidale meningiomas may have a poor surgical outcome due to the anatomic complexity as they can extend into nearby structures such as the sella turcica, posterior clinoid, and cavernous sinus (3).

Discussion:

CT is useful since it can demonstrate any meningiomas effect on adjacent bone and in detecting psammoma calcifications (1). On non-contrast CT, meningiomas appear isodense compared to adjacent brain tissue (Figs. 1A, B). On contrast CT, the meningioma will enhance and may or may not appear homogeneous (Fig. 1C, D) depending on the presence of calcium, fat, and tumor necrosis (2). Hyperostosis of adjacent bone suggests a benign meningioma. MRI has the ability to assess soft tissue characteristics including vascular supply and perfusion. On MRI with contrast, meningiomas and their dural tail/attachment will enhance, which reflects dural infiltration and/or reactive vascularity. Calcifications may appear as low signal intensity or areas void of vascular flow (2). On T1 weighted images, meningiomas appear isointense or hypointense and have signal variability on T2 weighted images. The use of diffusion-weighted imaging has been shown to aid in predicting the histological grade of meningiomas (3).

Treatment:

Depending on the tumor size and involvement of adjacent structures, planum sphenoidale meningiomas may be removed using approaches such as endonasal transsphenoidal resection. Early decompression of the optic canal and orbiotomy are critical for total resection with excellent outcomes (5).

References:

1. Ohba, S., Abe, M., Hasegawa, M., & Hirose, Y. (2016). Intraparenchymal Meningioma: Clinical, Radiologic, and Histologic Review. World neurosurgery, 92, 23–30. doi:10.1016/j.wneu.2016.04.098

2. Saloner D, Uzelac A, Hetts S, Martin A, Dillon W. Modern meningioma imaging techniques. J Neurooncol. 2010;99(3):333-340. doi:10.1007/s11060-010-0367-6

3. Ranabhat K, Bishokarma S, Agrawal P, et al. Role of MR Morphology and Diffusion-Weighted Imaging in the Evaluation of Meningiomas: Radio-Pathologic Correlation. JNMA; Journal of the Nepal Medical Association. 2019 Jan-Feb;57(215):37-44. https://europepmc.org/article/med/31080244

4. Finn JE, Mount LA. Meningiomas of the Tuberculum Sellae and Planum Sphenoidale: A Review of 83 Cases. Arch Ophthalmol. 1974;92(1):23–27. doi:10.1001/archopht.1974.01010010027007

5. Mortazavi MM, Brito da Silva H, Ferreira M Jr, Barber JK, Pridgeon JS, Sekhar LN. Planum Sphenoidale and Tuberculum Sellae Meningiomas: Operative Nuances of a Modern Surgical Technique with Outcome and Proposal of a New Classification System. World Neurosurg. 2016;86:270-286. doi:10.1016/j.wneu.2015.09.043

Neal Joshi is a medical student and aspiring diagnostic radiologist at Rowan University School of Osteopathic Medicine in New Jersey. Prior to medical school, he did research with mouse models for Parkinson’s disease and L-DOPA induced dyskinesias. He also did an internship at Kessler Institute for Rehabilitation in a stroke lab analyzing MR images in ischemic stroke patients with hemispatial neglect. During his time at Rowan, he did research with animal models for traumatic brain injury with an emphasis on electrophysiology of neurons. He graduated from William Paterson University where he completed his studies in biology and biopsychology. Apart from medical school, Neal loves to read, skateboard, go on hikes, and spend time with his friends.

Update July 2022: Dr. Joshi is a Radiology Resident at Thomas Jefferson University in Philadelphia.

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Kevin M. Rice, MD is the president of Global Radiology CME and is a radiologist with Cape Radiology Group. He has held several leadership positions including Board Member and Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator. He was once again a semifinalist for a "Minnie" for 2021's Most Effective Radiology Educator by AuntMinnie.com. He has continued to teach by mentoring medical students interested in radiology. Everyone who Dr. Rice has mentored has been accepted into top programs across the country including Harvard, UC San Diego, Northwestern, Vanderbilt, and Thomas Jefferson.

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