Probe-based confocal laser endomicroscopy (PCLE)

Tiny space age probes — those that can see inside single living cells — are increasingly being used to diagnose illness in hard-to-reach areas of the body.

New York-Presbyterian Hospital/Weill Cornell Medical Center’s Dr. Michel Kahaleh often threads a tiny microscope into the narrow bile ducts that connect the liver to the small intestine to hunt for cancer.

The U.S. Food and Drug Administration approved pCLE diagnostic systems for use in the bile duct and pancreas two years ago. The pCLE is a mini microscopic probe that is threaded inside a larger “spy glass” probe. The pCLE can then image blood vessels, mucosal structures and epithelial tissue in real-time, broadcasting these images on a large monitor for physicians to examine.

But the vast majority of institutions may still use a rather hit-or-miss technique to determine if a bile duct is cancerous. The traditional technique is to thread a probe inside the duct to where it is abnormally narrowed and then to use a small brush or tiny forceps to gather some cells that can then be biopsied in a lab. “But we still miss 20-30 percent of bile duct cancer or other tumors in this way, and that is unacceptable,” Dr. Kahaleh says.