CALL IT CLIA 88's Catch-22. In a few weeks the deadline quietly will pass for a national cytology proficiency testing (PT) program mandated by the Clinical Laboratory Improvement Amendments of 1988. But cytotechnologists and pathologists won't be scrambling to enroll. Instead, many will be working with federal policymakers to figure out how or whether valid, widespread PT can even be accomplished. Establishment of such a program, spurred by news accounts of cervical cancer deaths attributed to false-negative Papanicolaou (Pap) test results, is extremely complex. One of the main problems is the sheer volume of test slides it would take to start up a national testing program. When the federal government advertised last spring for contractors to provide the needed 26000 slides, there were no responses. The list of problems doesn't stop there. But experts want to ensure that PT is viewed in a proper perspective. It is an important link