Cytomorphology of mesenchymal lesions in a tertiary care centre and its correlation with histopathology.

Objectives: Fine needle aspiration cytology (FNAC) is a minimally invasive method for sampling a heterogenous lesion. It is one of the first-line investigations in the evaluation of soft tissue tumours. However, the heterogeneity of mesenchymal lesions pose a challenge to the cytological diagnosis. The present study aims at evaluation of the cytomorphological findings of mesenchymal lesions on FNAC along with their histopathological correlation.

Material and methods: This was a retrospective study conducted over a period of 1 year from January 2021 to January 2022. All the patients of cytologically diagnosed mesenchymal lesions on their FNA aspirates were included in the study. Cytomorphology of the May Grunwald Giemsa and Papanicolaou stained slides were examined and correlated with clinical and histopathological details wherever available.

Results: Out of the 90 patients, 69 (76.7%) were males and 21 (23.3%) were females. Maximum number of cases were in 4-5^th decade of life. The lower limb was found to be the most common site (57.8%) for the mesenchymal lesions. Majority of the cases on FNA in our study were found to be benign - 79 (87.8%), while only 11 cases were malignant (12.2%). On cytological examination, spindle cell lesions were most common followed by adipocytic lesions. Based on the cyto-histological correlation, sensitivity, specificity, negative predictive value, positive predictive value and diagnostic accuracy of FNAC in diagnosis of mesenchymal lesion was 78.6%, 100%, 92.5%, 100% and 94.1% respectively.

Conclusion: FNAC is a simple and minimally invasive tool that plays an important role in triaging patients with good specificity and sensitivity.