Objective To introduce the application of a new type of cell wax block vertical embedding technique in the pathological diagnosis of serous cavity effusion.

Methods Group experiments were carried out on 4, 437 cell wax block specimens of serous cavity effusion in Xi'an Daxing Hospital in the past nine years. The impacts of the traditional cell wax block embedding method in 1, 472 cases and the modified vertical embedding method in 2, 965 cases on the accuracy of cytopathological diagnosis were compared.

Results The accurate diagnosis of the type and origin of malignant tumors was 67.8% (206/304) by immunocytochemical staining (ICC) before the improvement, and 97.1% (469/483) by immunocytochemical staining after the improvement of embedding. The difference was statistically significant (P < 0.05). The cellular morphology of the embedded cell block closely resembled that observed in histology. Following the implementation of improved cell block techniques combined with immunocytochemical staining, there was a notable enhancement in the accuracy of diagnosing malignant tumors. ICC clearly identified adenocarcinoma, squamous cell carcinoma, small cell carcinoma, mesothelioma, breast cancer, malignant melanoma, soft tissue sarcoma, and other tumor types, with adenocarcinoma being the most frequently encountered subtype. Among these cases, respiratory system malignancies were found to be the most prevalent followed by those originating from the digestive system. The positive detection rates ranged between 12.8% and 21.0%.

Conclusion The improved embedding method of cell wax block is convenient for comparison and analysis of immunocytochemical multiple antibody labeling, effectively assisting cytopathologists to judge the source and type of malignant tumors, and improving the accuracy of cytopathological diagnosis. It has good effect in clinical practice and high application value, and thus is worthy of recommendation.