TruTest Questions

  • What is the TruTest?
    • The TruTest™ performs cervical brushings and endometrial biopsies to examine both histology and cytology, which are collected simultaneously using the TruTest endometrial brush method of sampling. The testing kit provided by Gynecor has one Tao Brush® (used for the collection of endometrial tissue), and two cytobrushes (one is used to ‘clean’ mucus and debris from the cervix and the second is used for enhanced cell and tissue collection from the squamo-columnar junction of the uterine cervix).

      The TruTest method of sampling is a process of obtaining endometrial tissue, via the Tao Brush and squamo-columnar junction cervical tissue via the cytobrushes. The Tao Brush is an FDA approved, Class II device used to obtain endometrial cell samples. The Tao® Brush head is 3.0 cm in length and samples the endometrium to a depth of 1.5 to 2 mm. Using this brush, a simple watch-winding motion collects endometrial cells and tissue in a quick and generally painless fashion, and yields excellent diagnostic outcomes.

  • What are the benefits of using the TruTest and Tao Brush?
    • The TruTest™ uses the Tao Brush® to sample a substantial portion of the endometrial surface’s lining. This can save a woman from undergoing a traditional endometrial biopsy, which is generally a more painful procedure. The Tao Brush affords a better tolerated invasive collection of endometrial tissue. When used correctly, it minimizes sample contamination from the endocervix and vagina, thus reducing a source of diagnostic error by confining sampling to the endometrial cavity (re-sheathing the brush before it is withdrawn from the uterine cavity is a critical step that protects and retains tissue during brush withdrawal).

  • Why use the Tao Brush instead of other endometrial samplers?
    • With the TruTest™, the operator gets a specimen more than 95% of the time, as compared to about 80% of the time with other samplers like the Pipelle®. The Tao Brush® is designed to achieve global sampling of the endometrial surface while causing less pain for the patient. Studies show that it may have greater sensitivity than pipelle: “A study conducted in 101 women compared two endometrial biopsy techniques, Tao Brush and Pipelle, using both techniques during the same office visit. Sensitivity for Tao Brush was 95.5 percent, and 86 percent for Pipelle's. Both have specificities and positive predictive values of 100 percent and negative predictive values of 98 percent.” Source: National Cancer Institute

  • Why turn in the cytobrushes with TruTest? Doesn’t this incur an added expense?
    • Yes, the additional diagnostic testing is billed and paid by the insurance carrier. The purpose of the Endocervical Cytobrushing is to detect unsuspected dysplasia in the endocervical canal. It can also detect possible involvement of the endocervix by endometrial adenocarcinoma. It can help pinpoint where the abnormal bleeding is originating and give a more comprehensive picture than just looking at the uterus alone. Since the opening of the cervix must be cleared of mucus prior to performing the endometrial biopsy, why discard that sample containing valuable information that can help in diagnosis the problem? In addition, including the endocervical vial gives the option for adding Chlamydia, gonnorhea or cystic fibroiss testing as well. (TruTest™ does require that both the endoocervical and endometrial specimens be submitted. If only one endometrial vial is being returned, please order a Tao brush® EMB on the requisition instead.)

  • Why clear the blood and mucus (and return it) when performing an endometrial brush biopsy? The Tao Brush is sheathed when inserted, doesn’t that protect it from contamination?
    • If the blood and mucus is not cleared, when the Tao Brush® is inserted, it will push the mucus and blood into the endometrial cavity. When the Tao Brush is then unsheathed the mucus not only dilutes the sample but it also adheres to the brush and thus prevents a sufficient amount of endometrium from being collected. Even if the Cytobrushes are not returned for processing, the mucus does still need to be cleared. Not doing so could result in an inadequate specimen and subsequent test failure.

  • When sheathing the Tao brush will we be dislodging tissue and cells?
    • Resheathing the brush does not cause tissue or cells to be dislodged. It does express some of the blood collected which allows a cleaner cytologic and histologic preparation to be made. If the brush is not resheathed, tissue and cells will be lost in the lower uterine segment and endocervical canal. One of the leading causes of an insufficient collection is failure to resheath the brush when it is removed from the uterine cavity; all the endometrial material can be lost.

  • Does the Tao Brush actually get tissue or is it only cells?
    • Both tissue and cells are collected by the Tao Brush®. The cytologic preparations do contain individual cells but most often they also contain intact glands, some of which have attached stroma, as well as small tissue fragments. The cytologic slides are prepared using a sedimentation technique so that no material is lost. Intact proliferative, secretory, inactive and neoplastic glands are recognizable on the cytology slides. The brush also collects larger tissue fragments which are submitted for histologic examination.

  • Is it possible for the Tao Brush to capture polyps?
    • From among approximately 1650 consecutive brushings that we reviewed, Gynecor reported out about 20 polyps. As with other office biopsy samplers, polyp acquisition is a serendipitous event. Hysteroscopy and snare biopsy or formal dilation and curettage remain the preferred ways of identifying and collecting polyps, especially large, symptomatic ones.

  • A physician may have a patient with an atrophic endometrium and cervical stenosis and this patient may retain a lot of fluid in the uterus. Will the collection from the TruTest endometrial brush be compromised?
    • Yes. This condition may represent a variety of changes such as blood or inflammatory cells and sometimes serous fluid in the uterus. This is usually due to cervical canal obstruction. In such cases, the retained fluid should be drained and the uterine wall lining sampled at a second setting after the uterine walls once more oppose each other (no matter what collection device is used).

  • What if the brush seems too thick to insert into a postmenopausal patient?
    • If the cervix is stenotic it must be dilated, regardless of the collection device used. Generally, we advise sounding the uterus before any collection procedure. If the sound passes easily, the brush generally does also.

  • If a patient has a thick endometrial stripe on ultrasound examination of the uterus, how much of the uterine lining will the TruTest endometrial brush collect?
    • About the upper 2 mm will be sampled. Most pathological conditions of the endometrium express themselves at the surface (stromal sarcomas are notable exceptions).

  • Can the TruTest be performed after using ultrasound gel?
    • Unless the gel is almost completely cleared out of the way of the cervical os, it would likely contaminate the collection and affect the quality of the cytology specimen.

  • Can the TruTest capture enough tissue if the patient is bleeding heavily?
    • Bleeding is an indication for endometrial biopsy so this is a common occurrence. We have seen many examples of adequate tissue and cytology during menstrual phase, even with menorrhagia. Unlike the suction straw device, which scrapes the endometrium and draws the blood into the sample, the proper use of the Tao Brush® tends to entrap tissue in the bristles, and then re-sheathing before removal helps by wringing out the blood to some extent, thus giving us a better tissue to blood ratio. Also, remember that Gynecor's unique fixative allows us to deliver a result on cytology from every specimen returned to us, regardless of what the tissue yields.

  • Can the Tao Brush be used in the presences of an IUD?
    • While there are no reports of complications, theoretically the brush could entangle in the IUD, and it would be prudent to inform the patient of this occurrence. It is recommended that an endometrial biopsy be performed prior to the insertion of an IUD.

  • Can the TruTest be used for endometrial dating for infertility testing?
    • Secretory endometrium can be dated from the cell block but not the cytology. It does require that a good sample be collected and returned with the Tao Brush®, as dating is difficult if the histologic material is small. The client would also have to specifically request dating on the Gynecor requisition.

  • Why is a specimen obtained with the Tao Brush taken at the fundus and not in the lower section of the uterus. Would a tumor in the lower section of the uterus be missed with this method?
    • Placing the bead of the brush of the fundus is the best method for collecting samples. Endocervical contamination is a problem and adherence to proper technique is needed to keep it at a minimum. Inserting the brush all the way to the fundus before retracting the sheath is part of that technique. Clearing the endocervical mucus with a cervix brush prior to using the Tao brush is another. Replacing the sheath before removing the brush through the endocervical canal is a necessary third measure. The 3.5 cm length of the brush (bristle portion) is sufficient to sample the average endometrial cavity. If the uterine cavity is known to be a good deal larger than average then two brushes can be used. Brushing the lower uterus would only increase endocervical contamination without increasing the yield of endometrium. We seldom lack lower uterine segment representation in our samples, even without specially targeting the area, another indication that the length of the brush is sufficient. In fact, the far more common problem is too much sampling of the LUS and not the rest of the endometrial cavity.

  • Why not wind the Tao Brush throughout the entire length of the cavity (while rotating), sampling the entire cavity, as opposed to using 2 brushes?
    • The Tao Brush® was designed and approved as a device for biopsing the endometrium. Diluting the endometrial sample with lower uterine segment and endocervical material would lead to an insufficient endometrial collection in most cases. Also, lower uterine segment and endocervical tissue do not add to the endometrial diagnosis. If clinically indicated, these areas could be sampled with the Cytobrushes.

  • How can you differentiate between a lower and upper endometrium?
    • If the report states, “NO ENDOMETRIAL TISSUE, ONLY LOWER UTERINE SEGMENT AND ENDOCERVIX” then the uterine fundus/ functionalis was not adequately sampled. In other words, when we say, ‘NO ENDOMETRIAL TISSUE”, we mean no functionalis. Reports may also state something about the endometrium (other than “no endometrial tissue”) and that lower uterine segment and endocervix were also present. This does not imply that the funtionalis sample was inadequate.

      We identify functionalis by the presence of stroma plus glands and/or surface epithelium. Lower uterine segment surface epithelium has a characteristic appearance and is usually not accompanied by the type of stroma that we identify as being from functionalis.

  • How can the Tao Brush procure more sample than the suction straw device?
    • The suction straw device procures more tissue since it rotates and scrapes vertically. On average, the amount of tissue collected by the Tao Brush and the suction straw device are roughly equivalent. The Tao Brush® does sample a much greater percentage of the endometrium area than does the suction straw device. There is less blood in the Tao Brush specimens and the tissue fragments are smaller, but the total amount of tissue is similar. In post-menopausal women with atrophic endometria, fewer insufficient samples are collected with Tao Brush and cytology is also available for diagnosis.

  • How do you grade endometrioid carcinomas, detected by the Tao Brush, and what is the advantage histologically of this technique over suction straw device?
    • Grading of endometrial carcinomas is essentially the same as with the suction straw device with the same provisos, i.e., it is based on a sample that is not the entire endometrium. (Any office biopsy and even dilatation and curettage are the same in this respect.) Subsequently, there may be undercalls compared with the hysterectomy diagnosis due to sampling, and there may also be overcalls because a high grade, but superficial and focal change, was removed by the biopsy sample but not included in the sampling of the hysterectomy specimen.

      Grading of type 1 carcinomas of endometrium in histopathology is based on percentage of solid growth pattern exclusive of squamous metaplasia. Solid growth may sometimes be seen in brush biopsy samples but we tend to rely more on cytological features. Principally (but not exclusively), the presence of grade 3 nuclear changes will up-grade an architectural type 1 grade 1 to a grade 2. The type 1 grade 3 should show discernable solid growth (unless bad luck would have it that we sampled only the 10% non-solid growth area of a grade 3 lesion) and high grade nuclear changes.

      Histologically, there is no advantage [nor any serious disadvantage] of the Tao Brush® over the suction straw device. The very important points however are two:

      • The Tao Brush® causes less pain to patients for comparable histological information (except for polyps, where the suction straw device does have an acknowledged edge)
      • Cytology can, and absolutely should, be used together with histology when evaluating Tao brush samples and the synergy of methods provides better performance, especially (but not exclusively) in the post-menopausal population where endometrium is sparse. This is not offered with the suction straw device.
  • Does ACOG or ASCCP have a position on performing cytology and histology with TruTest?
    • ACOG has taken no formal position on endometrial cytology. According to the FDA however, the Tao Brush® is a non-cervicovaginal cytology test. By convention, all non-cervicovaginal cytology tests in which sufficient material presents itself for cell block analysis should have cell blocks.