Utility of the capsule-based technique for cell block preparation - in body fluids and Liqui-PREP™ specimens

OBJECTIVE

The aim of this study was to find a better technique for the cell block preparation.

STUDY DESIGN

We developed a novel capsule-based technique and applied it to different cell block preparation materials including plasma thromboplastin (PT) clot and agarose gel-embedding medium, in order to concentrate the cells in a limited field, then compared the result with the widely used, modified alcohol fixative preparation technique based on specimen adequacy and diagnostic accuracy. Twenty-eight nongynecologic body fluids and 41 gynecologic Liqui-PREP™ (LGM International Inc., Fort Lauderdale, Fla., USA) cytology specimens were collected for cell block preparation. We performed routine hematoxylin and eosin staining on the cell block sections, which were scored according to four specimen adequacy parameters: background, cellularity, nuclear preservation and cytoplasmic preservation. The differences between the diagnostic results of cell block slide and conventional cytology smear were also presented.

RESULTS

The capsule-based PT clot technique in nongynecologic body fluids provided more cellularity in the cell block sections and reduced atypical diagnosis when compared to conventional smears.

CONCLUSION

We suggest the capsule-based PT clot technique is a better technique for nongynecologic body fluids in the preparation of a satisfactory cell block.

Reliable registration of preoperative MRI with histopathology after temporal lobe resections

PURPOSE

Conventional and novel magnetic resonance imaging (MRI) techniques can detect cerebral abnormalities in patients with refractory focal epilepsies. Correlation of preoperative MRI and histopathology is important to validate MRI findings, but in practice is far from straightforward. Peroperative neuronavigation and placement of markers on tissue is of limited use in temporal lobe resections. MRI scanning of the resected specimen for registration with in vivo MRI is complicated by anisotropic tissue deformation. We have developed a method to facilitate registration of preoperative MRI with the resected specimen and to enable correlation of MRI findings with histopathology.

METHODS

Sixteen en bloc temporal lobe resections undertaken for refractory temporal lobe epilepsy were studied. The specimens were fixed in formalin and then cut coronally by using a cradle with parallel blades at 5-mm intervals to ensure evenly thick tissue slices in the same orientation. Volumetric T1-weighted preoperative MRIs were reformatted, and consecutive slices (0.94 mm) cut in the same orientation as the resected lobe were visually compared with photographs of tissue slices by two independent observers.

RESULTS

In 15 (94%) of 16 cases, a <2-mm difference was found between the two observers' matches of MRI slices with tissue slices. In the last case, a 4-mm difference was noted. In all cases, a consensus was reached by the two observers. The suggested MRI-histology matches were within the resections seen on postoperative scans.

CONCLUSIONS

Careful labelling and postoperative handling and slicing ensured histopathologic tissue slices of uniform thickness and slicing angle. This technique can be applied to a range of MRI datasets, enabling exploration of the pathologic basis of abnormalities on conventional and novel MRI acquisitions.

A robust method for alignment of histological images

Determination of reference points is a precondition for reconstruction of serial sections. In the case of comprehensive reconstruction work, manual extraction of the markers may be very time-consuming and may even make such reconstruction impossible. The procedure presented in this contribution allows automatic alignment of histological preparations provided that nuclei or comparable structures extend over several sections and are capable of being extracted using methods of pattern recognition. The method was applied to 50 sections with Nissl staining. The nuclei were extracted from the images and evaluated by application of the algorithm. All image pairs were correctly aligned. An integrated control mechanism ensures automatic detection of incorrectly aligned images.

Sputum cytology for the diagnosis of lung cancer. Comparison of smear and modified cell block methods

OBJECTIVE

To compare the sputum smear cytology and cell block methods for specimen adequacy, cytology quality and diagnostic accuracy in the diagnosis of lung cancer.

STUDY DESIGN

We assessed 2,524 sputum specimens from 768 patients. The specimens were prepared as smears and cell blocks for cytopathologic examination between March 1, 1992, and December 31, 1998. The smear and cell block slides were evaluated both separately and together, and the results were compared with radiologic and histopathologic diagnoses.

RESULTS

The sensitivity of the smear method was 69.4% and specificity was 99.5%. The sensitivity of the cell block method was 84.4% and specificity, 100%. The sensitivity of the smear and cell block together was 87.6% and specificity, 99.5%.

CONCLUSION

The cell block method increases the sensitivity and specificity of sputum cytology, and when smear and cell block slides are evaluated together, sensitivity reaches its highest value. Therefore, application of smear and cell block methods together seems most useful in the diagnosis of lung cancer.

[Thin-layer cytology in endometrial diagnosis]

Our purpose was to test the liquid-based thin layer method on the endometrial cytology. One hundred sixty two consecutive patients before the hysterectomy (55 women because of various causes; 107 asymptomatic postmenopausal women because of prolapsed uterus) had the endometrial cytology (all women) and the biopsy (107 postmenopausal women prolapsed uterus affected). Cytohistologic concordance was 98%: all endometrial neoplasms and atypical hyperplasia (10 cases) and 15 of the 18 (83%) simple hyperplasias were diagnosed by thin layer endometrial cytology. In asymptomatic postmenopausal women cytology gave sufficient material for the diagnosis significantively more often than endometrial biopsy (respectively 82% and 24%; p = 0.000).