Cell block alone as an ideal preparatory method for hemorrhagic thyroid nodule aspirates procured without onsite cytologists

A comparative study of cytological processing techniques in hemorrhagic effusion

Objectives:

Fluids are one the most common specimens received in cytology laboratories. The presence of erythrocytes may obscure the cells in the smears, making the diagnosis, and identification of cells difficult. Many techniques are being used by laboratories to eliminate these erythrocytes. The present study was undertaken to improve the quality of cytology smears of hemorrhagic samples by comparing three different techniques, namely, Carnoy’s fixative (CF), modified CF, and normal saline rehydration technique (NSRT) to hemolysis red blood cells (RBC) present in the smear background for better cytological assessment. The present study was a prospective study done over 1 year 6 months from November 2012 to March 2014, in the Department of Pathology in a Tertiary Care Rural Medical College.

Materials and Methods:

All hemorrhagic effusions received in the department of pathology were processed using CF, modified CF, and NSRT. The background of the smear and cytomorphological details with two different stains was analyzed. The Chi-square test was used to find out the association of different techniques in the reduction of RBC.

Results:

More than 60% reduction of RBCs in the smear was noted in 85.40%, 14.60%, and 15.60% by NSRT, modified CF, and CF, respectively. Staining was better and nuclear features were best preserved in NSRT.

Conclusion:

NSRT is the best, simple, and cheaper technique to lyse RBC in the hemorrhagic fluid. It also shows better staining and well-preserved cytomorphological features of the cell.

Needle rinse cell blocks as an ancillary technique: Diagnostic and clinical utility in gastrointestinal neoplasia

BACKGROUND

Fine-needle aspirate (FNA) cytology is often the first-choice method for diagnosing gastrointestinal nodular lesions. The FNA material can be converted to histopathology specimens by a needle rinse cell block (NRCB) technique, allowing ancillary studies to refine the cytologic diagnosis. Despite use in human pathology, NRCB has never been applied to canine or feline gastrointestinal neoplasia.

OBJECTIVE

This study described NRCB methodology and its diagnostic utility in specific cases of neoplastic gastrointestinal lesions.

METHODS

Needle rinses with saline were performed after ultrasound-guided FNAs of two intestinal lymphomas (canine and feline) and a canine gastrointestinal stromal tumor (GIST). The NRCB was prepared using the cell tube block technique and processed for paraffin embedding. Routine immunohistochemistry protocols (using CD3, PAX-5, and Ki-67 for lymphoma cases and vimentin, desmin, S-100, and KIT markers for GIST) were applied to NRCB sections, and the results were compared with matched tissue biopsies.

RESULTS

NRCBs with adequate cell numbers, preservation, and good separation of blood were obtained. The diagnosis and immunophenotyping were confirmed in both cases of lymphoma in NRCBs. In the GIST, the immunolabeling of the neoplastic cells in NRCB was completely concordant with the tissue biopsy.

CONCLUSIONS

The described methodology is suitable for veterinary settings, having few technical requirements and low invasiveness. The presented cases of gastrointestinal neoplasia highlight the utility of NRCBs as a platform to conduct ancillary studies and refine the cytologic diagnosis.

Architectural aspects of cell-blocks as small biopsies

Cell-block preparations have become an essential part of integrated cytology diagnosis. They are essentially microbiopsies that are formalin fixed and embedded in paraffin. This has become more prevalent with greater sample procurement due to the advent of newer biopsy techniques and needles. Cell-blocks allow retrieval of small tissue fragments from cytology specimens that sometimes cannot be processed by alternate cytologic techniques. They represent concentrated, cell-enriched preparations that provide cytologists with the opportunity to evaluate cellular architecture, as well as to perform ancillary testing. A cell-block compatible sample may thus obviate the need for a more invasive procedure such as a tissue biopsy. Microscopic examination of cell-blocks is quick, avoids obscuring material, permits cells to be evaluated in one focal plane, and allows the histologic architecture such as glandular differentiation, papillary formations, and sometimes invasion to be easily identified. This new era of “cytohistology” accordingly requires practicing cytologists to become more familiar with histopathology. This review article discusses the benefit of various architectural patterns identifiable in cell-blocks employed as an adjunct to Pap tests, exfoliative fluid specimens, and fine-needle aspirations.

Utility of cell blocks obtained by catheter aspiration via a guide sheath during endobronchial ultrasonography

BACKGROUND

The demand for adequate tissue samples for both morphological assessment and molecular studies on lung cancer treatment has increased. The aim of this study was to evaluate whether cell blocks (CBs) prepared from endobronchial ultrasonography with guide sheath (EBUS-GS) rinsing following catheter aspiration provide additional information.

METHODS

We produced CBs from rinse fluid obtained from washing the inside of the sheath with saline after conventional EBUS-GS between May 2012 and April 2013. During the first 7 months, the sheath was aspirated with 20mL of negative pressure while moving the catheter back and forth [aspiration group (Asp)]. During the next 5 months, the sheath was not aspirated, but only rinsed out [conventional group (Con)]. Patients diagnosed with lung cancer by EBUS-GS and/or CBs were identified and evaluated. The diagnostic rate of each sampling method was compared between the two groups. The number of tumor cells was also compared between the CB and EBUS-guided transbronchial lung biopsy (EBUS-TBB) groups.

RESULTS

EBUS-GS was performed on 113 patients. Fifty-five patients were included in this study (Asp=30, Con=25). The diagnostic yield of CBs in Asp was higher than that in Con (56.7% vs 32.0%; p=0.06). Asp showed no significant difference in the number of tumor cells between CB and EBUS-TBB. One patient who showed negative EBUS-TBB pathological results but positive CB results was diagnosed only by immunohistological staining of CB.

CONCLUSION

CB prepared from EBUS-GS rinsing following catheter aspiration may provide additional information.

Ultrasound-guided fine-needle aspiration biopsy of the thyroid: methods to decrease the rate of unsatisfactory biopsies in the absence of an on-site pathologist

PURPOSE

The rate of unsatisfactory samples from ultrasound-guided fine-needle aspirations of thyroid nodules varies widely in the literature. We aimed to evaluate our thyroid ultrasound-guided fine-needle aspiration biopsy technique in the absence of on-site microscopic examination by a pathologist; determine factors that affect the adequacy rate, such as the number of needle passes and needle size; compare our results with the literature; and establish an optimal technique.

MATERIALS AND METHODS

We performed a retrospective review of cytopathology reports from 252 consecutive thyroid ultrasound-guided fine-needle aspiration biopsies performed by a radiologist between 2005 and 2010 in our hospital's radiology department. Sample adequacy, the number of needle passes, and needle size were determined. There was an on-site cytologist who prepared slides immediately after fine-needle aspiration but no on-site microscopic assessment of sample adequacy to guide the number of needle passes that should be performed. Cytopathology biopsy reports were classified as either unsatisfactory or satisfactory samples for diagnosis; the latter consisted of benign, malignant, and undetermined diagnoses.

RESULTS

Seventy-seven biopsies were performed with 1 needle pass, 124 with 2 needle passes, and 51 with 3 needle passes. The rates of unsatisfactory biopsies were 33.8%, 23.4% (odds ratio [OR] 0.599 [95% confidence interval {CI}, 0.319-1.123]; P = .110), and 13.7% (OR 0.312 [95% CI, 0.124-0.788]; P = .014), respectively.

CONCLUSION

In a hospital in which there is no on-site pathologist, a 3-pass method increases the specimen satisfactory rate by 20% compared with 1 pass, achieves similar rates to the literature, and provides a basis for further improvement of our practice.

A new technique for the diagnosis of mycetoma using fixed blocks of aspirated material

The aim of this prospective study was to evaluate the use of the cell block technique as a safe, accurate and quick tool for the cytodiagnosis of mycetoma. The study included 240 patients with suspected mycetoma. The suspected lesion was aspirated and the aspirated material was processed to form cell blocks. The cell blocks were processed as described for routine tissue histopathological examination. Haematoxylin/eosin-stained sections were reviewed to identify the morphological features of the mycetoma grains and the different inflammatory tissue reactions. The findings were compared with those seen in histopathological sections. The different mycetoma grains showed distinct morphological features on the cell block that were identical to those seen in histopathological sections. Distinction between eumycetoma and actinomycetoma and their classification according to the causative agent were possible. The cell block technique had sensitivities of 87.5% and 85.7% for eumycetoma and actinomycetoma, respectively, and there were no statistical differences in the findings obtained by the cell block and histopathological techniques. The technique is simple, rapid, specific, sensitive and inexpensive. It can be used in the routine diagnosis of mycetoma and to obtain grains for culture identification. The cell blocks can be preserved for a long period for future studies.