Significance of Plasma Thromboplastin Cell Block Technique as an Adjunct to Fine Needle Aspiration Cytology in Diagnosis of Breast Lesions

Introduction: Despite the fact that Fine Needle Aspiration Cytology (FNAC) has been widely utilised in the preoperative diagnosis of breast lumps, the Conventional Smears (CS) have drawbacks, including difficulty in understanding the pattern or architecture of the lesion, determining invasiveness, Immunohistochemistry (IHC), false positives, and false negatives. Cytologists advise using Cell Blocks (CB) to increase the diagnostic precision of FNAC. In this study, the significance of using Plasma Thromboplastin Cell Block (PTCB) routinely as an addition to CS in FNAC of palpable breast lesions.

Aim: To determine the significance of PTCB as an adjunct in addition to CS to diagnose breast lesions.

Materials and Methods: The present prospective observational study was conducted in the Department of Pathology, Chettinad Hospital and Research Institute, Kelambakkam, Chennai, Tamil Nadu, India, between July 2021 and June 2022 on 30 samples of palpable breast lesions. From the fine needle aspirates, smears were prepared and stained with Leishman and Papanicolaou stains. The residual material in the hub was rinsed in saline. The plasma-thromboplastin method was used to prepare CB, and Haematoxylin and Eosin (H&E) sections were made. A point scoring system was used and findings were compared to histopathology. IHC markers namely Estrogen Receptor (ER), Progesterone Receptor (PR), Human Epidermal Growth Factor Receptor-2 (HER2), Proliferation marker Ki-67 was utilised wherever appropriate. The results were analysed using Statistical Package for the Social Sciences (SPSS) software version 21.0.

Results: Out of total 30 subjects, majority (n=9, 30%) were in the age group of 41-50 years. The mean scores of CS {background (0.93±0.25), cellularity (1.7±0.55), morphology (1.7±0.47) and architecture (1.03±0.32)} and PTCB {background (1.77±0.43), cellularity (1.77±0.48), morphology (1.8±0.48) and architecture (1.5±0.57)} were compared using the point scoring system. Though the mean scores of all four parameters were higher in PTCB than in CS, the statistically significant difference was seen in background (p-value=0.001) and architecture categories (p-value=0.0001). The PTCB finding as a screening test for predicting histopathological diagnosis showed a sensitivity of 94.44%, specificity of 100%, Positive Predictive Value (PPV) of 100%, Negative Predictive Value (NPV) of 92.3%, and 96.67% accuracy. IHC staining was feasible in CB and findings were comparable to biopsy.

Conclusion: The routine use of PTCB technique in FNAC of breast lesions, along with smears, will aid in IHC, reducing diagnostic pitfalls, thereby reducing misdiagnosis and invasive procedures, particularly in suspicious for malignancy cases, which can lead to inappropriate radical treatment causing physical and psychological stress to patients.