"prime cases" is a perfectly acceptable phrase in written English.
It is used to refer to situations or occurrences which are particularly important or relevant. For example, you could say "The lawyer was only interested in the prime cases, leaving the simpler disputes to his assistants."
Through a series of examples, some experienced personally, she shows that aid not only fuels but helps expand conflict: the camps in Goma, Darfur and the play-out of the induced Ethiopian famine crisis are the prime cases.
Production cycles in birds are proposed as prime cases of indirect interactions in food webs.
The Michael J. Fox Foundation for Parkinson's Research, and The Breast Cancer Research Foundation are prime cases.
A prime case in point is BMW.
A prime case is Henry Kissinger's secret visit to China in 1971, which paved the way for Nixon's visit.
It is, unfortunately, a prime case of politicians offering emotional satisfaction because they cannot or will not offer any substantive relief from violent crime.
If the nation's largest bankruptcy, coupled with a clear example of paid political influence, isn't a prime case for reform, I don't know what is.
Lehmann also reiterated previous claims that Australia believe they have worked out some of England's batsmen, Jonathan Trott a prime case in point.
As a symptom, if not the whole cause, of England's struggle to rediscover their World Cup-winning rhythm, Greenwood's drought is a prime case study.
A prime case in point is provided by our (ie Anglo-American) response to the latest French initiative in internet control.
Iran's nuclear program is a prime case in point: so far, neither threats nor inducements have persuaded its leaders to suspend their uranium enrichment program.
