ThinPrep® vs. Conventional Smears in Fine‐Needle Aspirations of Sarcomas: A Morphological and Immunocytochemical Study

Abstract

Very limited data exist describing the characteristics of sarcomas sampled by fine-needle aspiration (FNA) and processed by the ThinPrep (TP) method. We compared the cytopathological and immunocytochemical features of sarcoma aspirates prepared using both the conventional and TP method. We reviewed 70 sarcoma FNAs. Samples were first used to prepare conventional smears and the remainder of the specimen was rinsed in Cytolyt. The average number of slides examined per case was two for the TP method and five for the conventional technique. Immunocytochemistry for different markers was performed in a subset of cases. Sixty-five cases were positive for sarcoma both by conventional and TP methods. Five cases were positive by one method only. Cellularity was higher on conventional slides. In terms of cytoarchitecture, TP slides revealed fewer thick clusters, more single cells that were more evenly distributed, and sometimes distortion of expected cellular arrangements and architectural patterns. Cytomorphological and nuclear details were better preserved on TP slides. The background of TP slides revealed a reduction of blood but also some loss of necrosis and characteristic background tumor features. Immunocytochemical staining revealed superior results on TP slides. TP and conventional slides showed good correlation. TPs were excellent for immunocytochemistry and represent an alternative to conventional smears when expertise in slide preparation is not available. However, TPs may require additional experience in the interpretation of sarcomas, mainly related to the loss of tumor-specific background features. They are useful as an adjuvant to conventional smears in sarcoma diagnoses, particularly when special studies are needed. Abstract presented at the United States and Canadian Academy of Pathology,

Improved preoperative definitive diagnosis of papillary thyroid carcinoma in FNAs prepared with both ThinPrep and conventional smears compared with FNAs prepared with ThinPrep alone

“…In general, these studies have shown that TP adequately preserves cellularity and that the cellular details are sufficient for diagnostic purposes. Certain diagnoses, specifically those in which the background material is important (as in some sarcomas, mucinous tumors, salivary gland lesions), may be more difficult to accurately diagnose with TP 3, 4…”

Comparison of ThinPrep® and conventional preparations in pancreatic fine‐needle aspiration biopsy

“…There is also increasing acceptance of the ThinPrep preparation in the processing of FNA of different body sites including breast, thyroid, and salivary glands. [5][6][7][8][9][10][11][12][13][14][15][16] However, information on the use of ThinPrep preparation in pancreatic FNA is scarce. 17 To the authors' best knowledge, there is no large series evaluating the use of ThinPrep preparation in pancreatic FNA.…”

Immunocytochemistry of serous effusion specimens: A comparison of ThinPrep® vs. cell block

“…Generally, antibodies that are available for use on formalin-fixed, paraffin-embedded cell blocks can also be used on a variety of cytology specimens. [1][2][3] The ThinPrep Processor (Cytyc, Boxborough, MA) has become increasingly popular as a cytopreparation technique for effusion specimens. One of the main advantages of ThinPrep is that it almost completely eliminates background interference caused by blood and proteinaceous debris.…”

“…Comparisons of immunostaining quality with ThinPrep and conventional smears from fine-needle aspiration (FNA) specimens showed good correlation on the vast majority of immunomarkers. [1][2][3] However, ICC data of ThinPrep effusion specimens are limited, 6 and comparison of staining with cell blocks has not been previously reported. The purpose of our study was to compare ICC results on both ThinPrep and cell-block slides prepared from the same effusion specimens.…”