Morphological features of cell blocks prepared from residual liqui-PREP samples can distinguish between high-grade...

To evaluate the diagnostic value and compare morphological features of cell block sections of high-grade squamous intraepithelial lesions (HSIL) and squamous cell carcinomas (SCC).

A total of 135 cell blocks were prepared from residual Liqui-PREP samples. Of these, 43 biopsy-confirmed cases (24 HSIL and 19 SCC) were reviewed. Morphological features determined included cell clusters, epithelial-stromal interface, stromal invasion and tumor necrosis.

Ninety-three percent (40/43) of cell block diagnoses were consistent with histological diagnoses, which was better than the cytological diagnoses (81.4%; 35/43). The mean cell block size was 0.54 cm (range, 0.3-1.0 cm) for HSIL and 0.84 cm (range, 0.4-1.4 cm) for SCC (p < 0.0001). Cell clusters were present in 70.8% (17/24) of HSIL and 100% (19/19) of SCC (p < 0.0001). No epithelial-stromal interface, stromal invasion or tumor necrosis was observed on HSIL cell block sections, which is in contrast to the 84.2% (16/19), 68.4% (13/19) and 42.1% (8/19) on SCC cell blocks, respectively (p < 0.05).

Cell blocks may increase the diagnostic accuracy of liquid-based cytology. The presence of stromal invasion, epithelial-stromal interface and tumor necrosis on cell block sections may be useful for accurate SCC diagnosis.