The phrase "a lone case of" is correct and usable in written English.
It can be used to refer to a singular instance or example of something, often implying that it is unusual or isolated.
Example: "The study revealed a lone case of the disease in an otherwise healthy population."
Alternatives: "an isolated instance of" or "a singular occurrence of".
Last autumn, seconds after an Auchan store had opened, I snatched a lone case of 2008 Haut-Bailly away from the outstretched arms of a suited gentleman, getting a nasty splinter in the process.
Atlantic cod AFGP genes are by no means a lone case of gene-rich repetitive sequences representing a major and/or novel trait.
Interestingly, a lone case of BSE in Washington state in December 2003 resulted in roughly 3.5 billion dollars in reduced export of beef in 2004 (http://www.bookstore.ksre.ksu.edu/pubs/MF2678.pdf).ksu.edu/pubs/MF2678.pdf
This is the lone case of an independent group taking footage from a candidate's video that originally included narration.
Unfortunately, this is not the lone case of a ball squeezing leading to serious consequences, and several doctors agree that there is some not-so-funny business behind male funny business.
Besides the lone case of a single PD patient the remaining sixteen reported R594H cases were all classified as SMDK or SMDK-like [2], [4].
The two incidents Ms. Fong discussed were those of the dairy cow in Moses Lake, Wash., that became the country's lone case of mad cow disease, last Dec. 23, and another in which a cow slaughtered in Texas in April was not tested even though it had symptoms of a brain disease.
These were included because of its "low-technological" approach for possible use in developing countries, despite the fact that evidence for this intervention vis-à-vis colorectal cancer is based on non-significant results from a lone case-control [ 18].
