College of American Pathologists
Printable Version

  Feature Story





cap today

Histology slides into a benchmark (and landmark) program

September 2004
Anne Paxton

Anyone who launches a project

that’s never been done before has to ask the same question: If you build it, will they come?

But the CAP and the National Society for Histotechnology, joint sponsors of a new quality assurance program that offers impartial evaluation of histology slides, have their answer. Now in its second year, the program called HistoQIP has won nearly 700 laboratories as subscribers and shows every prospect of bringing on hundreds more.

"This program is the first of its kind. Histology laboratories now have a way to benchmark against other laboratories in an objective fashion," says Richard W. Brown, MD, chair of the CAP/NSH Histotechnology Committee and director of laboratories at Memorial Hermann SW Hospital, Houston. "Every other section of the laboratory has a CAP Survey or some other means of objectively evaluating quality," he adds. "But there has never been a quality assurance or peer review program for histology labs in the United States."

As HistoQIP subscribers, laboratories submit slides and receive an assessment of their technique in fixation, tissue processing and embedding, microtomy, staining, and coverslipping. In addition to a grade for each, the evaluation includes educational critiques, peer comparison data, information on best-performing techniques, and benchmarking data.

The 2004 Surveys offered an assessment of H&E-stained slides of uterus, colon, bone marrow, and liver, as well as elastin, reticulin, Helicobacter (non-silver, non-immuno), and amyloid special stains.

HistoQIP had been on the National Society for Histotechnology, or NSH, drawing board for some time. "The society has been talking about an external quality assurance program for pretty close to 10 years—first anecdotally, then seriously for the last five years or so," Dr. Brown says. But logistical issues and the nature of histology itself have been the stumbling blocks.

"The real barrier to a program like this is there are so many variables involved in histology," he says.

Creating a histologic section involves many steps and is much more complex than most assays in the clinical laboratory, he notes. "Some people say cutting a good section is an art form. Learning how to embed and cut tissue is definitely an on-the-job training experience, like an apprenticeship. You really have to learn from someone who knows how."

Many people thought HistoQIP couldn’t happen. "There was never a program like this in the U.S. for histo tech nol o gists," says Lena T. Spencer, MA, HT(ASCP)HTL, QIHC, president of the NSH and a member of the CAP/NSH Histotechnology Committee.

"There were many programs for laboratory professionals, such as Cell Markers and other Surveys, but never one for histotechnologists. We felt it would certainly be something to make a difference in people’s lives. There was a real need to educate people as well as to look at the product they are putting out and make sure it’s high quality."

And the need to educate has only grown stronger because histotechnology has gone from a static field to a dynamic one, says Freida L. Carson, PhD, HT(ASCP), a member of the CAP/NSH Histotechnology Committee and retired director of the his to pa thol ogy laboratory at Baylor University Medical Center, Dallas. "For my first three decades in histotechnology, there was little change in technology or procedure.

"But in the last decade," she says, "there’s been almost an explosion of new equipment and new methods. For example, we now have disposable blades where we used to have to sharpen our own blades" and the sections weren’t nearly as good. "Now you always have a really sharp defect-free knife blade at your disposal. We’ve seen a tremendous improvement in the quality of sections just from that." Microwave technology also now enables a much faster turnaround time, she adds.

Nevertheless, quality remains an issue. "There are a lot of artifacts that can occur, and they can interfere with the pathologist’s reading of the slide and making a diagnosis," she says. "There are also problems in the processing of tissue, particularly since, because of the emphasis placed on turnaround time, we’ve shortened a lot of the fixation and processing time. Many times we’re just not getting as good a preparation as many years ago."

Dr. Carson helped the NSH launch the pilot project that eventually led to HistoQIP. For that initial test phase, the group recruited three pathologists and three histotechnologists from around the country and found 20 small to large hospitals to participate.

"In clinical laboratories such as chemistry, they spit out numbers, whereas in histotechnology the product is microscopic slides and they’re a bit more cumbersome to evaluate. So I think this was the first time anyone had pursued this as a pilot project," Dr. Carson says.

But progress toward an actual QA program was slow. Says Dr. Brown: "NSH spent at least three years trying to get the program off the ground, then finally realized it was just too big an undertaking for them in terms of marketing, statistical analysis, and the number of potential laboratories." At that point, he says, the NSH began to consider the possibility of partnering with the CAP.

Histotechnologists have a long history of submitting slides to have their work evaluated. In fact, histotechnology is the only ASCP-certified field that requires candidates to submit slides. But quality assurance is a different process from certification, Dr. Carson stresses.

"To be certified as a histotechnologist, you do submit a practical as part of your certification exam. But there, we’re grading a candidate and you’re expecting them to do their very best work. They have a long time to prepare slides. Here we are grading routine, day-to-day work against criteria and against other laboratories in the U.S."

Once the partnership between CAP and NSH was formed, HistoQIP swiftly became a reality, and the first Survey was distributed in 2003. But demand was much higher than the groups had expected.

"After we decided to do it as a partnership, we really weren’t sure. Would people sign up?" recalls Spencer, who is a histotechnologist for Norton Healthcare, Louisville, Ky.

"So we said, okay, we’ll limit it to 300 the first year. Then right away we had 400 laboratories. It was really eye-opening that there was such a need."

One of the early challenges was developing a grading system. What made the program possible, Dr. Brown says, was having a committee of people from the two groups find a way to objectively grade the slides. "Identifying standardized grading criteria was the biggest barrier," he says.

"Pathologists in the laboratory will look at a section and say, this is really good, or it’s terrible. But by and large they don’t have training in what makes a section good or not. What we had to do was come up with specific things you look for."

To bring that about, the Histotechnology Committee created an orientation that relates standard written comments to photomicrographs that are shown to all the graders immediately before the grading session. Twice a year 15 to 20 people come together to evaluate the slides. "The orientation makes the evaluation much more objective because everyone is using the same criteria," Dr. Brown says.

The committee has found that the evaluators tend to grade the slides the same way with little variation from grader to grader, and that has made it much easier for the program to grow.

Says Spencer: "Normally in a lot of programs, such as the MK Program for immunohistochemistry, CAP sends slides and asks you to perform ER or PR or HER2/neu. And that’s what made us unique. We’re getting down to the bare roots. We’re evaluating the processing, the microtomy, and your staining—which is different from other programs. We thought it might add difficult obstacles, but it hasn’t."

Dr. Brown says HistoQIP assesses the quality of the tissue processing, the section itself, whether it’s well cut or poorly cut, and the stain. "There are many variables in each of those steps—for example, how long the tissue is fixed in formalin, how big the pieces of tissue are that were submitted, and how carefully the section was cut. The H&E stain is now relatively routine, because it’s being done in most laboratories by an automated meth od."

"Originally," Spencer says, "we were doing at least three evaluations with different evaluators. But after running blind tests through all evaluators to see what the bias was, we found that everything was pretty much in line. It’s interesting when you have 20 or 30 people across the U.S., half pathologists and half technologists, and the grader bias isn’t significant."

Says Dr. Brown: "That meant we could actually have a single person look at each set of slides. That allowed us to expand enrollment." He believes the potential number of subscribers could be in the thousands. They expect greater interest in 2005 because of the addition of immunohistochemistry, which many labs requested and is "sorely needed," he says, for histotechnologists.

That is not to say there haven’t been snags along the way. "In the beginning," Spencer says, "I think we [the NSH] asked for more stains, and it became burdensome at that point." But HistoQIP’s developers decided to scale the program down, and she believes it has been kept under control by having a manageable four to five slides in each Survey.

Spencer says the CAP and NSH have been pleased with the findings from the first Survey rounds. "A great number of people from the sites supplying slides are actually doing a good job. I don’t want to sound surprised, but the quality is better than we anticipated."

Dr. Brown agrees. "What we’re finding is that quality is really quite good across all the laboratories. I wouldn’t say it’s rare to find a poor slide, but certainly they’re in the minority."

In response to the below-standard slides, HistoQIP is conducting statistical analyses to determine which problems are most common.

"The fact that there’s so much variability is very interesting," Dr. Brown says. Based on the first three submissions, "we thought we would be able to identify particular things that made one laboratory better than another, such as what kind of stainer they used, or what stains, so we asked all those questions on the survey."

"To our surprise, we have yet to find consistent reasons for poor performance. What that tells us is what we suspected already: The ability of the histotechnologist in the laboratory is the most important factor."

He and others believe that quality has more to do with the degree of quality control done in the laboratory and, specifically, whether histotechnologists are looking at sections daily and making sure they look good. "Daily involvement by both the senior histotechnologist and the pathologist, we think, is a crucial element. There may be an element of histotechnologists’ training, too," he says.

"For example, some laboratories use only people certified by ASCP, while others do not. Among HT certificants, there are people who are mainly on-the-job-trained and a relative few who actually trained through a NACCLS-accredited school. Those qualifications might make a difference, but we’re not sure."

Participants, especially laboratory supervisors, are finding HistoQIP to be an excellent means of demonstrating and enhancing quality in the laboratory, Spencer says. "Some are using the program for proficiency testing, and many use it for wonderful in-services showing slides and results and using the educational materials to help solve problems."

Eventually, she says, "we’re hoping 1,500 laboratories will sign up, but we’d love to see 1,000, which I do not think is out of the question as word gets out." She notes that there are histotechnologists in veterinary, industry, and research labs as well as clinical laboratories. "But we’re still that hidden part of the laboratory, and we really need administrators and laboratory managers to understand this program is there and the value it can have to support their laboratory."

"As a technologist, I can say this is a wonderful product. But if my laboratory manager is not willing to listen or to pay the prices of such a Survey, I’m up against a wall. So it really has to come from the laboratory manager," Spencer says.

In 2005, the HistoQIP program is asking a new series of demographic questions to address qualifications and quality control, and it will ask for submissions in immunohistochemistry for the first time. Because there are many different ways to do immunohistochemistry, the staining procedure is much more likely to vary, Dr. Brown notes. "You are basically localizing an antigen-antibody reaction in a tissue section, and there are many different chromagens and amplification systems."

But the developers are confident the challenges can be met and enthusiastic that HistoQIP has spark ed a rewarding collaboration between the NSH and the CAP. "We really didn’t know each other well," Spencer says, "and the people who have worked on this project have been exceptional—from the pathologists to the technologists to all the people at CAP. It’s exceeded anything we thought it would be."

It goes to show, she says, that a good partnership really can make a good product better.

Anne Paxton is a writer in Seattle.