Prussak's space is situated in:

(a) Epitympanum(Ref. Cummings, 6th ed., 1983)The space of the epitympanum, lying in between the Shrapnell's membrane or pars flaccida and the neck of malleus is known as "PRUSSAK'S SPACE".When the retraction pocket on Pars flaccida grows medially, it goes into this Prussak's space making this the most common site of primary cholesteatoma.