Deeper examination of negative colorectal biopsies

Value of additional sections: Tissue handling of small biopsies in detecting squamous dysplasia of the uterine cervix

Cervical cancer screening is currently based on high-risk human papillomavirus (HR-HPV) molecular testing, Pap cytology testing, and histologic evaluation of cervical biopsies. As primary HPV screening for cervical cancer becomes widely used, some of the recommended screening guidelines propose colposcopy and biopsies following positivity for HPV16/18 without cytologic triage. In such instances, a biopsy would be the only tissue sample available for informing further management. The use of additional histologic levels on cervical biopsies is commonly employed to achieve a diagnosis, although no set criteria for when to obtain additional levels exist. In this study, we evaluated the value of additional sections in cervical biopsy and endocervical curetting, as well as clinical and histologic features that should be considered when ordering additional levels. Additional levels were obtained for the following scenarios: benign mucosa with Pap discrepancy (HSIL or ASC-H interpretation), size discrepancy with the gross description, suspicious atypia for a high-grade lesion, and long-standing high-risk HPV infection. A change in diagnosis was observed in 21.4% of the cases, with an upgrade to a high-grade squamous intraepithelial lesion (CIN2-3) in 12.1% of cases. An initial impression of atypia significantly correlated with both a change in diagnosis and an upgrade to CIN2-3. In the era of primary HPV screening, when evaluating tissue samples following positive HPV test, small, atypical foci should be followed by additional levels. We recommend six (6) initial levels on all cervical biopsies, particularly if there is no loss of tissue between the levels, to ensure an accurate interpretation. This will be crucial in the timely and accurate identification of HPV-related intraepithelial lesions and proper subsequent management.

Deeper Sections: Its Frequency and Diagnostic Utility in Histopathology of Noncutaneous Small Biopsy Specimen in a Tertiary Hospital in Nepal

BACKGROUND

Biopsy is an important tool for accurate diagnosis of disease in histopathology which can be examined at multiple levels during microscopic examination. The initial sections may not be representative of the entire biopsy, which leads to frequent request for deeper sections. This study assessed the frequency and diagnostic utility of deeper sections in noncutaneous small biopsy specimens at a tertiary hospital. Material and Methods. All the formalin fixed noncutaneous small biopsy specimens received were processed for grossing followed by tissue processing and embedding. The paraffin-embedded blocks were cut into 3-5 µm sections, fixed in a glass slide, deparaffinised, and then stained with hematoxylin and eosin (H&E) stain as per the standard protocol. Deeper sections were instructed based on microscopic findings of initial slides. The overall frequency of deeper section, its levels of cutting, tissue survival, and outcome were assessed and interpreted for the final diagnosis.

RESULTS

A total of 125 cases (26.9%) from 464 samples received were requested for deeper sections. The most frequent deeper sections were from cervix (72 cases) followed by stomach (18 cases) and endometrium (17 cases). The deeper sections were performed most frequently at 4 levels (17.8%) followed by 5 levels (14.8%) and 6 levels (13.3%). Deeper sections revealed nondiagnostic additional features in 28.2%, while 2.2% showed additional diagnostic features. Likewise, 2.2% had tissue segment loss. The overall mean level showing additional features was 6 levels. Tissue survival increased in 13% cases and 1.5% had decreased survival. The most common reason for requesting deeper section was to enhance sensitivity and diagnostic accuracy of disease.

CONCLUSIONS

Deeper sections often contribute to final diagnosis. Therefore, deeper sections on biopsies that cannot readily be diagnosed on routine levels are recommended regardless of size of the lesion and there should be uniformity in the practice of deeper sections across the globe.

<p>Histopathological Diagnosis of Cervical Biopsies: Reduction of Sampling Errors with the Evaluation of a Third Histologic Level</p>

Aim

Cervical cancer (CC) is considered as a major public health problem; this disease affects mainly vulnerable women in poverty, causing a negative effect on a country’s workforce.

Objective

To determine the histopathological diagnosis variation after examining three more levels of cervical biopsy paraffin blocks from patients with HPVI, CIN and CC.

Materials and Methods

A quantitative, retrospective correlational study was performed in a hospital with a second level of health care. We worked with 152 paraffin blocks of CIN (CIN, I, II and III) and cervical cancer samples. Currently, CIN I is considered as a set of low-grade injuries (low-grade squamous intraepithelial lesions, LSIL), while CIN II, CIN III and cancer in situ are considered as high-grade lesions (high-grade squamous intraepithelial lesions, HSIL). A slab was prepared with the 50micron block, which was subsequently cut into 5 microns; later, the same thing was done at two more levels to reevaluate the histopathological diagnosis and correlate it with the initial diagnosis issued by the institution.

Results

During the examination of the additional block levels, a difference was observed from the initial diagnosis: of 32 cases of HPV diagnosis, there were 17 changes to CIN I; of 31 cases of CIN I, there were 4 changes to CIN II; of 30 cases of CIN II, there were 8 changes to CIN III and 1 change to invasive cancer; of 29 cases of CIN III, there were 9 changes to cancer in situ; and finally, of 14 cases of cancer in situ, there was 1 change to invasive cancer. After the statistical analysis, a value of p <0.05 was obtained, which indicated that the differences were statistically significant.

Conclusion

By modifying the histopathological study technique, guidelines can be given to generate a more accurate diagnosis with a more solid base, and thus, a more appropriate and timely treatment can be offered to avoid the development of cervical cancer.

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CD8+ T cell infiltration in breast and colon cancer: A histologic and statistical analysis

The prevalence of cytotoxic tumor infiltrating lymphocytes (TILs) has demonstrated prognostic value in multiple tumor types. In particular, CD8 counts (in combination with CD3 and CD45RO) have been shown to be superior to traditional UICC staging in colon cancer patients and higher total CD8 counts have been associated with better survival in breast cancer patients. However, immune infiltrate heterogeneity can lead to potentially significant misrepresentations of marker prevalence in routine histologic sections. We examined step sections of breast and colorectal cancer samples for CD8+ T cell prevalence by standard chromogenic immunohistochemistry to determine marker variability and inform practice of T cell biomarker assessment in formalin-fixed, paraffin-embedded (FFPE) tissue samples. Stained sections were digitally imaged and CD8+ lymphocytes within defined regions of interest (ROI) including the tumor and surrounding stroma were enumerated. Statistical analyses of CD8+ cell count variability using a linear model/ANOVA framework between patients as well as between levels within a patient sample were performed. Our results show that CD8+ T-cell distribution is highly homogeneous within a standard tissue sample in both colorectal and breast carcinomas. As such, cytotoxic T cell prevalence by immunohistochemistry on a single level or even from a subsample of biopsy fragments taken from that level can be considered representative of cytotoxic T cell infiltration for the entire tumor section within the block. These findings support the technical validity of biomarker strategies relying on CD8 immunohistochemistry.

Negative colorectal polyp biopsies: the utility of cutting deeper levels

The objectives of this study were to determine the frequency with which deeper levels reveal a lesion in polyp biopsies where no polyp was found on initial sections and to identify features that predict such occult (histologically unapparent) lesions. All initially negative biopsy specimens were accumulated over an 18-month period. Following standard sections, three to ten levels were cut, 50 μm apart. The presence of any lesion, the level at which it was found, the location, number and size of fragments, number of levels obtained, presence of any lymphoid aggregate, endoscopic size and appearance, and bowel preparation quality were recorded. There were 214 specimens, mean patient age 61.4 years (range 27-86 years). Deeper levels revealed a lesion in 52/214 (24.3 %) cases; 76.9 % were tubular adenomas (TA), 21.2 % were hyperplastic polyps, and one was a leiomyoma. All TAs were negative for high-grade dysplasia and malignancy. The mean level at which TAs were found was 1.85 (range 1-9). Male sex (p = 0.021) and right-sided location (p = 0.0075) were statistically significant predictors of an occult TA. As the presence of an adenoma affects screening, pathologists should consider "pursuing" polyps when initial sections reveal no lesion, after ascertaining the incidence of occult lesions in their own practice.

Methods to become a high performer in characterization of colorectal polyp histology

The recent advent of advanced imaging technologies has brought real time characterization of polyp histology to the forefront. This concept of optical diagnosis of diminutive polyp histology can bring about a huge paradigm shift in the management of these lesions. Instead of resecting and sending all the diminutive polyps to pathology, there is the potential to practice "resect and discard" for those predicted to be adenomas and "do not resect" strategy for the recto-sigmoid polyps predicted to be hyperplastic. However, one of the major steps before the clinical implementation of real-time histology can be a reality, will be training endoscopists with varying levels of experience in novel imaging technologies. The two major methods for training include didactic teaching and the computer based method. After the initial training, it is imperative that the endoscopists practice this skill during performance of routine colonoscopy to auto validate and assess their own competency. Both practice and reinforcement can help endoscopists become high performers in the characterization of polyp histology.

Narrow band imaging to differentiate neoplastic and non-neoplastic colorectal polyps in real time: a meta-analysis of diagnostic operating characteristics

PURPOSE

Many studies have reported on the use of narrow band imaging (NBI) colonoscopy to differentiate neoplastic from non-neoplastic colorectal polyps. It has potential to replace pathological diagnosis of diminutive polyps. We aimed to perform a systematic review and meta-analysis on the real-time diagnostic operating characteristics of NBI colonoscopy.

METHODS

We searched PubMed, SCOPUS and Cochrane databases and abstracts. We used a two-level bivariate meta-analysis following a random effects model to summarise the data and fit hierarchical summary receiver-operating characteristic (HSROC) curves. The area under the HSROC curve serves as an indicator of the diagnostic test strength. We calculated summary sensitivity, specificity and negative predictive value (NPV). We assessed agreement of surveillance interval recommendations based on endoscopic diagnosis compared to pathology.

RESULTS

For NBI diagnosis of colorectal polyps, the area under the HSROC curve was 0.92 (95% CI 0.90 to 0.94), based on 28 studies involving 6280 polyps in 4053 patients. The overall sensitivity was 91.0% (95% CI 87.6% to 93.5%) and specificity was 82.6% (95% CI 79.0% to 85.7%). In eight studies (n=2146 polyps) that used high-confidence diagnostic predictions, sensitivity was 93.8% and specificity was 83.3%. The NPVs exceeded 90% when 60% or less of all polyps were neoplastic. Surveillance intervals based on endoscopic diagnosis agreed with those based on pathology in 92.6% of patients (95% CI 87.9% to 96.3%).

CONCLUSIONS

NBI diagnosis of colorectal polyps is highly accurate--the area under the HSROC curve exceeds 0.90. High-confidence predictions provide >90% sensitivity and NPV. It shows high potential for real-time endoscopic diagnosis.

3-D visualization and quantitation of microvessels in transparent human colorectal carcinoma [corrected]

Microscopic analysis of tumor vasculature plays an important role in understanding the progression and malignancy of colorectal carcinoma. However, due to the geometry of blood vessels and their connections, standard microtome-based histology is limited in providing the spatial information of the vascular network with a 3-dimensional (3-D) continuum. To facilitate 3-D tissue analysis, we prepared transparent human colorectal biopsies by optical clearing for in-depth confocal microscopy with CD34 immunohistochemistry. Full-depth colons were obtained from colectomies performed for colorectal carcinoma. Specimens were prepared away from (control) and at the tumor site. Taking advantage of the transparent specimens, we acquired anatomic information up to 200 μm in depth for qualitative and quantitative analyses of the vasculature. Examples are given to illustrate: (1) the association between the tumor microstructure and vasculature in space, including the perivascular cuffs of tumor outgrowth, and (2) the difference between the 2-D and 3-D quantitation of microvessels. We also demonstrate that the optically cleared mucosa can be retrieved after 3-D microscopy to perform the standard microtome-based histology (H&E staining and immunohistochemistry) for systematic integration of the two tissue imaging methods. Overall, we established a new tumor histological approach to integrate 3-D imaging, illustration, and quantitation of human colonic microvessels in normal and cancerous specimens. This approach has significant promise to work with the standard histology to better characterize the tumor microenvironment in colorectal carcinoma.

Incidence of diagnostic change in colorectal polyp specimens after deeper sectioning at 2 different laboratories staffed by the same pathologists

OBJECTIVES

To calculate the incidence of nondiagnostic (ND) colorectal (CR) polyp cases in which deeper tissue sectioning rendered new diagnostic information--particularly adenomas--in 2 laboratories staffed by the same pathologists.

METHODS

After initial diagnosis, 100 ND CR polyps from each laboratory were reexamined with 3 deeper levels to establish rates of diagnostic conversion based on biopsy specimen location and original observation(s).

RESULTS

Deeper sectioning rendered new diagnostic information in 43 (21.5%) of 200 biopsy specimens and specifically adenomas in 16 (8.0%) of 200 biopsy specimens.

CONCLUSIONS

These results support routine ordering of deeper levels on ND CR polyps to improve adenoma detection rates, especially those cases without any histologic abnormality. If another biopsy in the same case already is adenomatous, examination of deeper levels may not be necessary, as it may not have any significant effect on the clinical management of the patient.

Comprehensive evaluation of colorectal polyps in specimens from endoscopic biopsies

Modern evaluation of specimens from biopsies of colorectal polyps has become increasingly complex because of tremendous progress in the understanding of colorectal neoplasia. Although pathologists are generally familiar with the basic handling of carcinoma in the setting of polypectomies or resections, the comprehensive evaluation of specimens from biopsies of colorectal polyps obtained with forceps is far from intuitive and has yet to be reviewed. Comprehensive evaluation requires always addressing several key issues, even when dealing with seemingly routine cases. These issues include taking further action when initial sections lack polyps, accurately quantitating polyps, accurately classifying polyps, determining whether thresholds are met for considering conditions at high risk for carcinoma, detecting incidental findings other than polyps, and determining which incidental findings are clinically significant. In particular, polyposis with attenuated phenotype or Lynch syndrome may be clinically occult, and the possibility of these entities should always be kept in mind, regardless of age or history. Ancillary studies performed immediately on carcinoma that is detected at biopsy guides surgery, guides medical therapy, prognosticates, provides evidence for hereditary neoplasia, and guides surveillant colonoscopy for the family.

Squamous Dysplasia of the Uterine Cervix

Despite the technological advances in colposcopic techniques, there continues to be a 10% to 20% discordance rate between the colposcopic findings and the histological diagnoses on the resultant biopsies. One of the many factors to which this may be theoretically attributable is related to sampling error from the paraffin-embedded tissue block. In this study, we evaluated the clinical efficacy of routinely obtaining 6 sections in cervical biopsies, using the frequency with which dysplastic lesions would be missed with various levels of sectioning as the sole benchmark determinant of clinical efficacy. Our database was searched for all cervical biopsies in which a diagnosis of squamous dysplastic lesion was made for the period February 1, 2006 to April 28, 2006. All cases were processed in 6-level sectioning, which entails cutting and staining (hematoxylin-eosin) 6 consecutive sections from the paraffin block without preserving or discarding any intervening unstained sections. The first level at which a diagnosis of dysplastic lesion could be unequivocally made by a gynecologic pathologist was determined. Six hundred consecutive biopsies from 404 patients were reviewed. For the whole cohort, the average level at which a dysplastic lesion was unequivocally diagnosable was 1.9 (median, 1). Three hundred fifty-seven (59.5%), 97 (16.2%), 41 (6.8%), 55 (9.2%), 34 (5.7%), and 16 (2.6%) of the 600 lesions were diagnosable at levels 1, 2, 3, 4, 5, and 6, respectively. The cervical intraepithelial neoplasia (CIN) 2 and 3 (n = 89) was, on average, diagnosable at an earlier level (1.35) compared with CIN 1 (level, 2.025; P < 0.001 [n = 511]). Indeed, 79.8% of the CIN 2-3 cases were diagnosable at level 1, as compared with 56% of the CIN 1 cases (P < 0.001); 87, 38, 52, 32, and 16 cases of CIN 1 and 10, 3, 3, 2, and 0 cases of CIN 2-3 were diagnosable at levels 2, 3, 4, 5, and 6, respectively. Therefore, if sectioning were limited to 3 levels, 17.5% (105/600) of all dysplastic lesions would have been missed, including 19.6% (100/511) of CIN 1 and 5.6% (5/89) of CIN 2-3. Because not more than 3 levels are routinely evaluated in most laboratories, our findings suggest that sampling error is indeed at least 1 significant factor contributing to colposcopic/histological discrepancies. Using our clinical efficacy standard, when no pathologic findings are initially identified in a colposcopic-directed biopsy, at least 5 levels (a priori or in recuts) are required to ensure a 100% diagnostic accuracy for CIN 2-3.

Multinucleated stromal giant cells in colonic lamina propria

AIMS

Multinucleated stromal giant cells occur in the anus, genitals and many other organs. They resemble myofibroblasts, react to local injury and are found incidentally or in association with various lesions. They have only rarely been reported to occur in the colon. The aim was to firmly establish their existence in colorectal lamina propria.

METHODS AND RESULTS

Specimens from one hundred biopsies taken from throughout the colon (70%) and rectum (30%) were retrospectively reviewed. Multinucleated stromal giant cells occurred in 23 specimens (23%), were pancolonic but surprisingly spared rectal mucosa (0%). Multinucleated stromal giant cells occurred in both normal mucosa and abnormal mucosa and appeared to be larger and more numerous in abnormal mucosa than in normal mucosa. Specimens with tubular adenomas appeared to have strikingly abundant multinucleated stromal giant cells with large numbers of nuclei. Immunohistochemistry and ultrastructural examination showed features consistent with myofibroblastic differentiation.

CONCLUSIONS

We have firmly established the existence of multinucleated stromal giant cells in colonic lamina propria and confirm their myofibroblastic differentiation. They may be more common in abnormal mucosa and particularly prominent in the setting of tubular adenoma. Absence of rectal multinucleated stromal giant cells may represent a microanatomical difference between the colon and rectum.

Three-dimensional virtual microscopy of colorectal biopsies

Conventional optical microscopy of specimens from colorectal biopsies commonly produces diagnostic errors due to incomplete sampling or poor orientation. Obtaining additional sections or re-embedding may help avoid these errors, but can prolong turnaround time. We describe new technology, which incorporates exhaustive sectioning, 3-dimensional reconstruction, and virtual microscopy, that may eliminate these problems by enabling pathologists to rapidly examine entire specimens and convert poorly oriented mucosa to well-oriented mucosa.

Noncorrelating Pap tests and cervical biopsies: Histological predictors of subsequent correlation

Lack of correlation between dysplastic cervicovaginal Papanicolaou (Pap) tests and subsequent cervical biopsies raises the concern that a significant squamous intraepithelial lesion (SIL) may go unconfirmed. Additional tissue sections of cervical biopsies may detect SILs after noncorrelation on initial sections. Complete step sectioning of paraffin blocks was undertaken on 111 noncorrelating biopsy specimens from 95 patients and selected slides were reviewed for the presence of SIL. The initial negative biopsy slides were evaluated for four histological features: chronic cervicitis, acute cervicitis, mucosal erosion, and squamous atypia. Twenty-seven biopsies (24.3%) demonstrated the presence of a SIL in deeper levels. The presence of squamous atypia was significantly associated with the presence of dysplasia deeper in the block (P < 0.002). Acute and chronic cervicitis was seen roughly equally. Additional tissue levels are a productive way of confirming SILs, and squamous atypia allows a refined selection of negative cervical biopsies most likely to reveal an SIL on review of deeper levels.

Gastrointestinal polyposis in childhood: clinicopathologic and genetic features

Gastrointestinal polyps and certain extraintestinal lesions in children may herald a hereditary polyposis syndrome, with an increased risk of neoplasia and other health problems for both children and their relatives. The availability of molecular/genetic screening tests has increased early diagnosis of younger members of known polyposis families. This article reviews the gross and microscopic features of polyposis syndromes of childhood and summarizes the molecular/genetic advances in this field. Clinical management is also briefly discussed.

Sampling error in the standard evaluation of endoscopic colonic biopsies

It is assumed that the diagnostic information in small gastrointestinal mucosal biopsies is obtained regardless of which side of the biopsy is sectioned. Based on this assumption, mucosal biopsies of the colon are embedded randomly with respect to the side of the biopsy that faces the microtome blade. Our hypothesis is that reorienting ("flipping") the biopsy specimen 180 degrees and sectioning the opposite side might provide new diagnostic information in cases with no specific histopathologic diagnosis. Sixty-one consecutive cases with a clinical impression of a polyp and no histologic abnormality on three hematoxylin and eosin-stained slides (6-15 levels) were selected. Formalin-fixed, paraffin-embedded tissue was reoriented, and three additional hematoxylin and eosin-stained slides (6-15 levels) were evaluated. The side of the specimen initially sectioned was arbitrarily designated "A," and the side of the specimen sectioned after reembedding was designated "B." The slides were sequentially numbered 1-3, and the first slide on which the new diagnosis was evident was recorded. New diagnoses were made for 19 of 61 (31.1%) specimens from a total of 51 patients and included tubular adenomas (12 of 61; 19.7%) and hyperplastic polyps (7 of 61; 11.5%). In 17 of 19 specimens (89.5%), the new diagnosis was evident on the first slide. Reembedding endoscopic colonic biopsies facilitates rendering a definitive diagnosis in cases of discordance between the clinical impression and the histologic impression. Routine examination of at least two sides of randomly oriented biopsy material could provide additional diagnostic, and sometimes critical, information.