Fossa navicularis magna

Last revised by Mostafa Elfeky on 4 Aug 2023

Citation, DOI, disclosures and article data

Citation:

Deng F, Elfeky M, Fossa navicularis magna. Reference article, Radiopaedia.org (Accessed on 16 Apr 2024) https://doi.org/10.53347/rID-81948

DOI:

https://doi.org/10.53347/rID-81948

Permalink:

https://radiopaedia.org/articles/81948

rID:

81948

Article created:

8 Sep 2020, Francis Deng ◉

Disclosures:

At the time the article was created Francis Deng had no recorded disclosures.

View Francis Deng's current disclosures

Last revised:

4 Aug 2023, Mostafa Elfeky ◉

Disclosures:

At the time the article was last revised Mostafa Elfeky had no financial relationships to ineligible companies to disclose.

View Mostafa Elfeky's current disclosures

Revisions:

3 times, by 2 contributors - see full revision history and disclosures

Tags:

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Synonyms:

Fossa navicularis (clivus)

Fossa navicularis magna, or sometimes simply fossa navicularis, is a variant depression on the ventral/inferior surface of the basioccipital portion of the clivus. It is a notch-like or rounded defect upon which the smaller pharyngeal fossa (foveola pharyngica) is superimposed ¹. The prevalence is 1–8% ^1,2.

Terminology

Fossa navicularis magna is often confused with canalis basilaris medianus, of which one incomplete type may be called an enlarged pharyngeal fossa. They may both represent the same spectrum of osseous defects presumably related to notochord migration ^4-6.

If making a distinction is desired based on their names, it may be more suitable to use "fossa" navicularis magna when the defect is a depression where the opening is wider than it is deep, and "canalis" basilaris medianus when the defect is a tubular structure where the opening is narrower than it is deep.

Fossa navicularis magna should not be confused with the urethral structure of a similar name: fossa navicularis.

Related pathology

Fossa navicularis magna is generally considered of no clinical significance, but there are rare reports of it acting as a route for infection to spread from the nasopharynx to the skull base and intracranial compartment ^6,7.