Significance of Tissue Microbiopsies in Fine Needle Aspiration Cytology- A Prospective Study

Background: Fine needle aspiration cytology is an indispensible technique, both as a modality of pre-therapeutic investigation and also in diagnosing recurrences. The role of fine needle aspiration cytology (FNAC) in the diagnosing malignant tumours is recorded. Yet it is not always possible to arrive at a definitive diagnosis based on FNAC alone. Certain pitfalls are there in conventionally assessed FNA smears. Often, they contain very less quantity of tissue material and the relative absence of recognizable tissue architecture in cytology smears often makes diagnosis very difficult.Fine needle aspiration (FNA) smears prepared through conventional method, often contain well preserved viable tissue fragments which are intact (tissue microbiopsies). Micro biopsies are defined as well preserved viable tissue fragments obtained on cytology smears. They will provide information on the tissue architecture and thereby contribute to the tumour ontogeny. This study was done to assess the significance of the presence of microbiopsies in conventional/guided FNAC in giving a more precise diagnosis.

Aim: To Study the Significance of Tissue Microbiopsies in Conventional/Guided Fine needle aspiration Cytology preparation and to assess the utility of the microbiopsy fragments in giving a precise cytological diagnosis.

Methods: A prospective study of significance of tissue microbiopsies in fine needle aspiration cytology were studied and interpreted during the period from June 2014 to June 2015 in the Cytopathology laboratory of the Department of Pathology, Tirunelveli Medical College, Tirunelveli. 100 cases with clinically palpable Swellings were studied.

Results: Out of 100 cases, 82% of cases were coming under the category of conventional FNAC, 10% of the cases were USG guided and 8% were falling under CT guided FNAC. Lymph nodes had the highest yield of microbiopsies, with 34 cases (34%), followed by breast 24 cases, thyroid 11 cases, lung 8 cases, salivary gland 7 cases, liver and bone and soft tissue 4 cases each, abdominal mass 3 cases, pancreas 2 cases, and ovary, spleen, and anterior mediastinum 1 case each. There were 56 percent malignant cases and 44 percent benign instances out of a total of 100 cases. There were 56 malignant tumours in total, with 41 (73.2%) being primary tumours and 15 (26.8%) being metastatic tumours.

Conclusion: FNA smears containing microbiopsies are of more help in establishing confirm diagnosis, typing of tumour, and predicting possible primary sites in cases of metastatic tumors which were not possible by cytology alone. Hence, this technique can be used to increase the diagnostic accuracy of FNAC, if put into practice in evaluation of routine cytology sample. Whatever be the types of FNAC, conventional, CT or USG guided, fine needle aspiration cytology aspirate with tissue microbiopsy is an effective tool in evaluating and diagnosing suspected lumps or masses.