Fine-needle aspiration cytology in soft tissue tumors: How far did we go??

Abstract

Objective: Assignment of the tumors into various cytological categories and to determine specific sub-typing in individual cases. To correlate the cytological features observed with histological parameters and analyse the reasons for discordant diagnosis. Materials and Methods: 27 cases, with both cytological and histopathological details, diagnosed as soft tissue tumors (STT) were included. The lesions were classified into 6 cytological categories. Results: On fine-needle aspiration cytology (FNAC), 14 cases were reported positive for malignant cells and 13 were reported as benign. On histological follow up discordant lesions were further characterized. Discordance was attributable largely to sampling in lipomatous lesions and interpretation errors due to inattention to clinical history, low volume of these lesions in practice, and overlapping cytomorphologic features with other entities. Sensitivity and specificity was 84.61% and 85.71% respectively and overall diagnostic accuracy was 85.18%. Conclusion: Soft tissue tumors are rare neoplasms that pose a significant challenge as a result of their morphologic overlap and biological heterogeneity. 'Time-honored' histopathology is recognized as the 'gold standard' for evaluation of STT. FNAC can be used as a diagnostic modality in soft tissue lesions due to its lesser cost, ease of performance, safety, along with reasonable specificity and sensitivity. In the current era, where 'needle is preceding the scalpel' and the biopsy material is getting limited, our study highlights the role and scope, diagnostic difficulties and pitfalls to be aware of when interpreting these challenging FNACs.

Role of FNAC in soft tissue tumors and its histopathological correlation

“…In a study by Chatura et al, such difference in findings of cytology and histology was noticed in 9 cases out of 27. 4 In this study, the overall accuracy in diagnosing soft tissue tumours by FNAC was 97.7%. Accuracy for diagnosing benign soft tissue tumours was 100% and for malignant tumours accuracy was 94.5%.…”

“…This combined with its relatively low cost makes it an important alternative more traditional biopsy technique in the rapid work up of palpable tumour invading the musculoskeletal system. 4 However, FNAC of soft tissue lesions has not been widely used because of concern about its diagnostic accuracy. The difficulties arise in exact typing and diagnosis of low grade sarcomas.…”

A Correlative Study on Spindle Cell Sarcoma With Cyto-Histological Grading by Conventional Methods in an Indian Tertiary Care Teaching Hospital

“…Pack, 1954 stated, the critics of aspiration biopsy are too specific in their demand of the method [15]. Chatura et al, 2015, is of the opinion that cytoarchitectural findings in conjunction with clinical correlation and ancillary methods have broadened the diagnostic spectrum [16]. Ricardo Gonzalez -Campora establish six basic categories, e.g., round cell tumor, myxoid tumor, pleomorphic tumor, spindle cell tumor, epithelial-like cell tumor, mature like cell tumor basing on stromal characteristic, cell shape and resemblance to normal tissue.…”

“…Nonetheless, FNA is not without pitfalls, some of which are derived from the nature of the tumor such as -scarcity of cells in the aspirate, tumor heterogeneity, focal nature of certain sarcomatous overgrowth, absence of strict criteria, for diagnosis of some sarcomas and last but not the least -limited experience of pathologist owing to low incidence of sarcomas [16,19].…”

“…In the hands of the expert; cytopathologist, it can afford a diagnostic specificity >90% [16,19] so it is considered valuable tools in the management of soft tissue tumor. For practical purposes, pattern analysis is always recommended.…”