Sinonasal meningioma

Case contributed by Dr Dalia Ibrahim


Recurrent sinonasal ethmoid masses after repeated surgical excisions.

Patient Data

Age: 45 years
Gender: Female

An irregular soft tissue mass lesions are seen centered upon both ethmoid air cells. They protrude into the nasal cavities, more on the left. The left ethmoid lesions show small left intra-orbital extension seen at the left superomedial extra-conal aspect of the left orbit, displacing the left medial rectus laterally. The lesions also show small intra-cranial extension at the olfactory grooves. They also extend into the frontal sinus. The lesions elicit isointense signal on T1 WI and high signal on T2 with homogenous post-contrast enhancement. Sclerosis of the adjacent crista galli and nasal bone.

Clinical diagnosis: Mass at biopsy

Nature of specimen: Biopsy


Two containers were received as:

  • Right: multiple grayish-white tissue pieces. Collectively measured 1.5 x 1.5 cm, totally submitted.

  • Left: multiple grayish-white tissue pieces. Collectively measured 1.5 x 1.5 cm, totally submitted.


sections examined from both specimens revealed partial squamous covering and respiratory covering, showing underlying tumor tissue formed of bland meningothelial cells, with oval vesicular nuclei and eosinophilic cytoplasm. No sheeting. No necrosis. No mitotic activity.

No evidence of malignancy in the sections examined.


Mass at both ethmoids, biopsy, extracranial meningothelial meningioma, WHO grade 1.


Case Discussion

Meningiomas that occur outside the cerebrospinal axis can be primary at an extracranial site (nasal cavity, paranasal sinuses, and nasopharynx) or secondary extending from an intracranial lesion. In our case, it is considered secondary as it shows a small intracranial extension.

Ectopic meningiomas might occur in the orbit, nose, paranasal sinuses, oropharynx, or even remotely (e.g lung).

Primary ectopic meningiomas may occur secondary to ectopic arachnoid tissue.

Radiological features included sinonasal masses with adjacent bone hyperostosis or bone erosion.


Ectopic sinonasal meningiomas need to be differentiated from:

  • inflammatory or a granulomatous process

  • neoplastic processes

    • epithelial: inverted papilloma, carcinoma

    • neurogenic: olfactory neuroblastoma

    • bone, cartilaginous: sarcoma

    • vascular: angiofibroma

    • hematopoietic: lymphoma

    • mesenchymal: ossifying fibroma


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