Diagnosing Helicobacter pylori by imprint cytology: can the same biopsy specimen be used for histology?

Imprint cytology: a useful screening test for diagnosis of Helicobacter pylori in resource poor settings

Objective

The study aimed to compare the usefulness of two staining methods for imprint cytology for diagnosis of Helicobacter pylori infection. Gastric biopsy specimens (from dyspeptic patients attending routine upper gastrointestinal endoscopy) were placed on glass slides to obtain imprints. The imprints were stained with Toluidine blue and Giemsa stains separately and observed under ×400 magnification using a light microscope. Imprinted biopsies were sectioned and stained with H & E stain and Giemsa stain for histological analysis. Diagnosis of H. pylori infection in both imprint and histological sections were confirmed by a consultant pathologist. The sensitivity, specificity, positive predictive value and negative predictive value of each stain were calculated and benchmarked against histological diagnosis.

Results

Of the 55 dyspeptic patients enrolled in the study, 5 were positive for H. pylori by Toluidine blue stain and 4 by Giemsa stain. The sensitivity of Toluidine blue stain (57.1%) was higher than Giemsa stain (42.9%) while the specificity of both stains was equal (97.9%). Giemsa stain gave a better discrimination for identification of H. pylori bacteria among the mucosal background. Imprint cytology is a rapid, simple and cost effective diagnosis method that can supplement histological diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3592-2) contains supplementary material, which is available to authorized users.

Depletion of Core Needle Biopsy Cellularity and DNA Content as a Result of Vigorous Touch Preparations

CONTEXT

Touch preparations (TP) of core needle biopsies (CNBs) are used at some institutions for on-site assessment of CNB adequacy. In our clinical practice, we have encountered instances in which TPs resulted in substantial depletion of CNB cellularity.

OBJECTIVE

To examine the effect of increasingly vigorous TPs on cellularity and DNA content of CNBs.

DESIGN

Ex vivo CNBs (n = 56) were performed on resected lung and kidney tumor specimens. For each specimen, CNBs were performed in quadruplicate on tumor and nontumor tissue and subjected to 1 of 4 TP methods: imprint, 1-cm drag, 2-cm drag, or full-slide drag. Overall cellularity in TPs relative to corresponding CNBs was estimated semiquantitatively. DNA was extracted and quantified from 12 TPs and corresponding CNBs. Two cytopathologists performed a blinded diagnostic assessment of Diff-Quik-stained TPs.

RESULTS

Cellularity of imprint, 1-cm, 2-cm, and full-slide TPs represented, on average, 19%, 33%, 41%, and 46% of total CNB cellularity, respectively (p = .003). Average DNA content in imprint, 1-cm, and 2-cm TPs was 0.3 μg (range, 0.1-0.8 μg), 0.4 μg (range, 0.1-1 μg), and 0.6 μg (range, 0.2-1.3 μg), respectively, which represented on average 15%, 36%, and 50%, respectively, of total CNB DNA content. Diagnostic accuracy was not inferior for less-extensive TPs, compared with more-extensive TPs.

CONCLUSIONS

Vigorous TPs may contain a substantial fraction of CNB cellularity and DNA content, whereas more-limited TPs are less disruptive to CNBs but remain suitable for cytologic assessment. We suggest avoiding excessively forceful TPs and, whenever clinically feasible, obtaining additional samples to ensure sufficient cellularity for potential ancillary studies.

Touch cytology in diagnosing Helicobacter pylori: comparison of four staining methods

OBJECTIVES

Helicobacter pylori (Hp), a major cause of peptic ulcer disease and an important risk factor for gastric malignancy, can be diagnosed by several methods. Touch cytology (TC) of the gastric mucosa has been noted to give good results and has been found to be very simple, inexpensive and rapid. However, evidence regarding the accuracy of different staining methods of TC is lacking. The present study aims at defining the diagnostic accuracy of four different staining methods of TC.

METHODS

Biopsy specimens were taken from the antral mucosa of one hundred consecutive patients referred for upper gastrointestinal endoscopy (UGIE) for various indications. TC slides were processed by four staining methods: Wright, Giemsa, Papanicolaou and Gram. Rapid urease test (RUT) and histological examination of specimens were also performed. The same experienced pathologist evaluated the coded samples. A patient's Hp status was established by minimum concordance of the three tests, including histology, RUT, and 'Touch mean'. The latter was defined positive when at least three of the four TC staining methods were positive.

RESULTS

Forty-six patients (46%) were positive for Hp according to Hp status. TC stained by Wright had excellent agreement with both histology (kappa = 0.80, P < 0.001) and RUT (kappa = 0.84, P < 0.001). Regarding Hp status, histology was 100% sensitive and RUT was 100% specific. Wright-stained TC (88.89%) was significantly more specific than both Giemsa- (74.07%; P < 0.05) and Papanicolaou-stained (70.37%; P < 0.05) TC.

CONCLUSIONS

RUT should still be acknowledged as the primary test in diagnosing Hp following UGIE. If RUT is negative and Hp detection is intended only, Wright-stained TC can safely substitute for histology. However, when assessment for severity of mucosal damage or cell atypias is meant, histology cannot be neglected.

Histopathological evaluation of ocular microsporidiosis by different stains

Background

There is limited data on comparing stains in the detection of microsporidia in corneal biopsies. Hence we wanted to evaluate various stains for their ability to detect microsporidia in corneal tissue sections.

Methods

Four cases diagnosed with microsporidiosis on Hematoxylin and Eosin and Periodic Acid Schiff's stained sections of the corneal button between January 2002 and December 2004, were included. Further sections were prospectively stained with calcofluor white, Gram, Giemsa, Masson's trichrome, acridine orange, Gomori's methenamine silver, Gram's chromotrope and modified acid fast stain. The stained sections were analyzed for the spore characteristics in terms of size, shape, color contrast, cell wall morphology, waist band in cytoplasm and ease of detection.

Results

All sections showed microsporidial spores as 3 – 5 μm, oval bodies. 1% acid fast, Gram's chromotrope and GMS stains provided a reliable diagnosis of microsporidia as diagnostic waist band could be identified and good contrast helped distinguish the spores from inflammatory debris.

Conclusion

Considering the ease of performance, cost effectiveness and rapidity of the technique, 1% acid fast stain and Gram's chromotrope stain are ideal for the detection of microsporidia.

Evaluation of the one-minute ultra-rapid urease test for diagnosing Helicobacter pylori

To determine the diagnostic accuracy of the one-minute ultra-rapid urease test for diagnosing Helicobacter pylori infection, two biopsies were taken from both the gastric corpus and antrum from 1000 patients undergoing upper gastrointestinal endoscopy. All the biopsies were subjected to the one-minute ultra-rapid urease test before imprint smears were prepared from them. Thereafter, the biopsies were fixed in 10% formalin and histological sections were examined for the presence of H pylori by a pathologist who was not aware of the clinical details or the results of the urease test. The prevalence of H pylori in the gastric antrum and corpus was 86.7% and 53.3%, respectively. The sensitivity, specificity, positive and negative predictive value and the overall diagnostic accuracy of the ultra-rapid urease test to diagnose H pylori infection in the gastric antrum were 92%, 100%, 100%, 66%, and 93%, respectively. The corresponding figures for the gastric corpus were 83%, 100%, 100%, 85%, and 91%, respectively. It is concluded that the one-minute ultra-rapid urease test has a high sensitivity and specificity and may be used as a rapid and cheap method to diagnose H pylori infection.