Prussak’s space is the small middle ear recess. It lies medial to pars faccida, lateral to the neck of malleus, above the lateral process of malleus and inferior to the lateral malleal ligament. The lateral malleal ligament also bounds it anteriorly and posteriorly. Posteriorly, it also has a gap through which the space communicates with epitympanum.
Prussak’s space is the sub component of the lateral epitympanic space and extends from the level of scutum to the umbo. This space is bent demonstrated radiologically on the oblique coronal image.
This space can play an important role in the retention of keratin and subsequent development of cholesteatoma. A cholesteatoma form when there is a deep retraction pocket in IM. The lining of the tympanic membrane which is skin(epithelium )is shed but if the membrane is retracted it gets trapped. The debris collects and enlarges and ultimately forms a cholesteatoma. This cholesteatoma in turn can erode the middle ear ossides, facial nerve, inner ear and even involve the brain.
From Prussak’s space located in epiyympanum cholesteatoma patterns of spread are: