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Vestibular fossa

The vestibular fossa, also called the vaginal vestibule, is the space within the female external genitalia bounded by the labia minora. It is a recessed region of the vulva into which the urethral opening, vaginal introitus, and ducts of the vestibular (Bartholin’s and Skene’s) glands open. This area is clinically significant due to its involvement in infections, cysts, trauma, congenital anomalies, and neoplasms. It is also an important site for surgical and imaging evaluation of vulvar and perineal diseases.

Synonyms

  • Vaginal vestibule

  • Vulvar vestibule

  • Vestibule of the vagina

  • Fossa vestibuli

Location and Boundaries

  • Anteriorly: External urethral meatus

  • Posteriorly: Posterior commissure of labia minora and the fourchette

  • Laterally: Medial margins of the labia minora

  • Superiorly: Clitoris and frenulum of clitoris

  • Inferiorly: Perineal body

Relations

  • Openings within the fossa:

    • Urethral orifice (anterior part of fossa)

    • Vaginal orifice (posterior-central part of fossa)

    • Ducts of the greater vestibular glands (Bartholin’s glands) open posterolaterally

    • Ducts of the lesser vestibular glands and Skene’s glands also open here

  • Closely related to the perineal membrane and pelvic floor musculature

Function

  • Serves as the common external space for the vaginal and urethral openings

  • Allows drainage of secretions from Bartholin’s and Skene’s glands

  • Important in sexual intercourse as it receives secretions aiding lubrication

  • Contributes to protection of internal genitalia from infection

Clinical Significance

  • Bartholin’s cyst/abscess: Presents as swelling in posterolateral vestibular fossa

  • Vulvovaginitis: Vestibule may be inflamed or erythematous

  • Trauma/tears: Common in childbirth or sexual injury

  • Vulvar carcinoma: May arise in vestibule, requiring careful imaging and biopsy

  • Congenital anomalies: Atresia or abnormal gland openings may affect this region

MRI Appearance

T1-weighted images:

  • No fluid: Vestibular fossa appears collapsed, filled with soft tissue signal

  • Fluid: Low signal intensity if simple; high if hemorrhagic/proteinaceous

  • Fat: Bright signal outlining labial margins and perineal fat

T2-weighted images:

  • No fluid: Appears as soft tissue recess with low-to-intermediate signal

  • Fluid: Bright signal intensity

  • Fat: Intermediate-to-bright signal outlining surrounding vulvar tissues

STIR (Short Tau Inversion Recovery):

  • No fluid: Fossa not well visualized, normal tissues suppressed

  • Fluid: Bright hyperintense signal

  • Fat: Suppressed (dark), highlighting inflammatory or cystic lesions

T1 Fat-Sat Post-Contrast:

  • No fluid: Minimal to no enhancement in normal fossa

  • Fluid: No enhancement of simple fluid

  • Fat: Suppressed (dark)

  • Pathology (Bartholin abscess, carcinoma, inflammation): Rim or heterogeneous enhancement

CT Appearance

Non-Contrast CT:

  • No fluid: Vestibular fossa not distinctly seen; appears as soft tissue space between labia minora

  • Fluid: Appears as low-attenuation focus in the fossa

  • Fat: Seen as low density surrounding structures

Post-Contrast CT:

  • No fluid: No specific enhancement, normal perineal fat planes visible

  • Fluid: Simple fluid does not enhance; infected or necrotic collections may show rim enhancement

  • Fat: Low attenuation; inflamed fat shows stranding in infection/abscess

MRI image

Vestibular fossa MRI coronal anatomy image-img-00000-00000

MRI image

Vestibular fossa MRI coronal anatomy image-img-00000-00000_00001

CT image

Vestibular fossa ct axial image