Consider this. A pregnant cockroach carries her eggs in a hard capsule called an ootheca, in which they incubate, intact, until the larvae (or "nymphs") hatch, bursting the capsule open from the inside. The eggs themselves are tiny and delicate, and couldn't survive at all outside the ootheca, let alone flourish within the body of a mammalian host. It would be highly improbable, is what I'm saying, to find viable cockroach eggs strewn about on random surfaces — least of all on the folded flap of an envelope.
Consider, too, the logical inconsistencies in the story. How is it that when the victim visited her doctor the first time, reporting a paper cut and showing visible signs of "abnormal swelling," he found "nothing wrong"? And what was the point, during the second doctor visit, of x-raying the poor woman's tongue? The "lump" allegedly detected by the x-ray was already in plain sight.