The phrase "a unique case study of" is correct and usable in written English.
It can be used when introducing a specific example or analysis that is distinct or singular in nature, often in academic or research contexts.
Example: "This paper presents a unique case study of the impact of urbanization on local wildlife populations."
Alternatives: "an exceptional case analysis of" or "a distinctive examination of".
They provide a unique case study of episcopal engagement with Roman criminal law at a time when bishops in general, and the Roman bishop in particular, increasingly assumed a role in civil judicial administration.
Large treeshrews represent a unique case study of FBD because they form behaviorally monogamous pairs that persist for several breeding periods [and potentially for life, 46], but also exhibit substantial extra-pair paternity [45].
Monkeypox provides a unique case study of "slow-motion" emergence (over decades), which is ideal for developing methods that can be applied to other prepandemic pathogens.
The 2008 Beijing Olympic Games provided a unique case study to investigate the effect of source control measures on the reduction in air pollution, and associated inhalation cancer risk, in a Chinese megacity.
The subsequent investigation provided economists with a unique case study into the effects of futures trading on agricultural prices.
A unique case study shows that the therapeutic effects of OV in the treatment of PSC + IBD do not always endure after OV discontinuation, with relapse of PSC associated with a decrease in blood Treg levels; subsequent OV retreatment was then associated with a rise in blood Treg levels and normalization of liver function tests (LFTs).
Military communities present a unique case study because they are semi-closed populations of people who share common location, responsibilities, and way of life.
On the higher-end of the spectrum, Selfridges is a unique case study as it's applying pressure to designer brands to promote more transparency.
It is both a rapidly moving microcosm of worldwide trends in transportation, and a unique case study.
