In human anatomy, Prussak's space is the small middle ear recess, bordered laterally by the flaccid part of Shrapnell's membrane, superiorly by the scutum (a sharp bony spur that is formed by the superior wall of the external auditory canal) and lateral malleal ligament, inferiorly by the lateral process of the malleus, and medially by the neck of the malleus.

[2][3][4] Prussak's space is important because it is a site for pars flaccida acquired cholesteatoma formation.

[5] A cholesteatoma forms when there is a deep retraction pocket in the tympanic membrane.

The debris collects and enlarges and ultimately forms a cholesteatoma.

From Prussak's space, located in the epitympanum, cholesteatoma patterns of spread are: