European Journal of Cardiovascular Medicine

Soft tissue tumors (STTs) represent a heterogeneous group of neoplasms arising from mesenchymal tissues, including adipose, fibrous, vascular, and peripheral nerve sheath elements. They constitute nearly 1% of all neoplasms but show a wide spectrum ranging from indolent benign lesions such as lipomas to aggressive high-grade sarcomas with significant morbidity and mortality [1]. The extremities are the most frequent sites of involvement, accounting for approximately 60–70% of soft tissue sarcomas [2]. Accurate preoperative diagnosis is essential because the clinical presentation is often nonspecific, and therapeutic strategies vary significantly between benign and malignant tumors [3].

Fine-needle aspiration cytology (FNAC) has emerged as an important first-line diagnostic technique for STTs due to its simplicity, cost-effectiveness, and minimally invasive nature. It allows rapid outpatient evaluation, helping clinicians in early treatment planning and avoiding unnecessary excisions [4]. Studies have reported that FNAC can reliably differentiate benign from malignant lesions, with diagnostic accuracy ranging between 85–95% [5,6]. Additionally, FNAC can often suggest a probable histological subtype, especially in lipomatous, spindle cell, and vascular lesions [7].

Despite these advantages, FNAC has certain limitations. Its interpretation depends on the adequacy of aspirated material, tumor heterogeneity, and the cytopathologist’s expertise [8]. Subtyping of sarcomas is particularly challenging, as overlapping cytological features between spindle cell sarcomas, fibrous lesions, and reactive proliferations can lead to misdiagnosis [9]. Furthermore, low-grade sarcomas may yield paucicellular smears, contributing to false negatives [10]. Therefore, histopathology remains the gold standard, particularly for grading and subtyping, and FNAC is best considered as a complementary diagnostic tool.

In the Indian context, FNAC has an added value because of limited access to advanced diagnostic modalities in many healthcare settings. Studies from tertiary centers in India have demonstrated encouraging results, with diagnostic accuracies of 88–94% [11,12]. However, the performance of FNAC varies across institutions and geographic regions, necessitating local validation.

The present study was conducted to evaluate the diagnostic accuracy of FNAC in soft tissue tumors of extremities at Bombay Health Care, Ujjain, with histopathology as the gold standard. By analyzing its sensitivity, specificity, predictive values, and overall accuracy, this study aims to establish the utility of FNAC as a rapid, reliable, and cost-effective diagnostic tool in a regional healthcare setting.

Study design and duration

A prospective observational study conducted at Bombay Health Care, Ujjain, from May 2024 to April 2025.

Inclusion criteria

• Patients with palpable soft tissue tumors in extremities.
• Patients undergoing both FNAC and histopathological confirmation.

Exclusion criteria

• Recurrent tumors with prior histology.
• Cases without histopathological reports.

FNAC procedure

Performed using a 22–23 gauge needle and 10 ml syringe. Smears were stained with Giemsa and H&E stains. Results were categorized as benign, malignant, or suspicious.

Histopathology

Biopsy/excision specimens were processed as per standard protocol. Histopathology was the gold standard.

Statistical analysis

Diagnostic indices were calculated with histopathology as reference.

A total of 120 patients with clinically suspected soft tissue tumors of the extremities were included in the present study. The demographic details, site distribution, and histopathological spectrum of tumors were analyzed. FNAC findings were correlated with subsequent histopathological diagnoses to assess diagnostic accuracy.

Table 1. Demographic distribution of patients (n=120)

Table 2. Distribution of soft tissue tumors by site (n=120)

Table 3. Histopathological spectrum of tumors (n=120)

Table 4. FNAC vs Histopathology correlation

Table 5. Diagnostic performance of FNAC

Figure 1. Distribution of soft tissue tumors by histopathological diagnosis (bar chart) with cumulative percentage (line graph). Lipoma was the most common benign lesion, while pleomorphic sarcoma was the most frequent malignant tumor. FNAC findings were correlated with histopathology, which served as the gold standard.

The present study evaluated the diagnostic accuracy of FNAC in soft tissue tumors of extremities over a one-year period. We observed a sensitivity of 90%, specificity of 97.1%, PPV of 95.7%, NPV of 93.1%, and overall diagnostic accuracy of 94.2%. These findings reaffirm the usefulness of FNAC as a first-line diagnostic modality in the evaluation of extremity masses.

Our results are in close agreement with those reported in earlier studies. Akerman et al. [5] demonstrated an overall accuracy of 91% in a series of 220 soft tissue tumors. Similarly, Rekhi et al. [11], in a large Indian cohort, reported a diagnostic accuracy of 92.5%. A recent meta-analysis by Khalbuss and Teot [6] highlighted that FNAC achieves sensitivity ranging from 80–95% and specificity exceeding 90%, consistent with our study.

Strengths of FNAC

The high specificity (97.1%) in our study indicates that FNAC is particularly effective in ruling out malignancy, which is crucial in avoiding overtreatment of benign lesions. This is especially relevant in resource-limited settings, where unnecessary surgeries can be minimized. FNAC is also cost-effective, rapid, and minimally invasive, making it ideal for outpatient evaluation [4,7]. In our series, FNAC provided valuable preliminary information in 93% of cases within 24 hours of presentation, enabling quicker treatment decisions.

Causes of diagnostic errors

Despite its advantages, FNAC was not without limitations. We observed five false-negative cases, mostly low-grade spindle cell sarcomas misdiagnosed as benign fibrous proliferations. This aligns with earlier reports by Nagira et al. [10], who emphasized that low cellular yield and morphological overlap in spindle cell lesions contribute to underdiagnosis. On the other hand, we encountered two false-positive cases, where reactive fibrous lesions were overinterpreted as sarcomas. Similar findings were documented by Layfield et al. [9], who noted that reparative and inflammatory lesions may mimic malignancy cytologically.

Tumor distribution

In our study, lipoma (42.8%) was the most common benign tumor, and pleomorphic sarcoma (32%) the most frequent malignant lesion. These observations are consistent with previous Indian series [11,12], where lipomas dominated benign lesions and pleomorphic sarcoma was the commonest malignant category.

Comparison with other diagnostic approaches

Core needle biopsy has been advocated as an alternative to FNAC in soft tissue tumors, with the advantage of providing tissue architecture and allowing immunohistochemistry [2,8]. However, FNAC remains attractive in developing countries because it is quicker, less invasive, and more cost-effective. Furthermore, FNAC can be repeated with minimal discomfort if samples are inadequate. Importantly, FNAC combined with radiological guidance significantly improves diagnostic yield in deep-seated lesions [7].

Clinical implications

Given its high diagnostic accuracy, FNAC can serve as a triaging tool—helping clinicians decide between conservative management for benign lesions and aggressive treatment for malignant ones. It can also aid in planning the extent of surgery and selecting patients for further ancillary testing.

Limitations of the study

Our study had a few limitations. First, the sample size, though adequate, was relatively modest compared to larger multicentric studies [6,11]. Second, ancillary techniques such as immunocytochemistry and molecular studies were not routinely applied, which could have improved subtyping accuracy. Finally, the study was conducted at a single tertiary center, which may limit generalizability.

Future directions

Future research should focus on integrating FNAC with ancillary diagnostic modalities such as immunocytochemistry, flow cytometry, and molecular assays, which can enhance tumor typing and prognostication [3,8]. Larger multicentric studies are also warranted to validate these findings across diverse populations.

FNAC is a safe, rapid, and highly accurate diagnostic technique for soft tissue tumors of extremities. It serves as a valuable first-line investigation, especially in outpatient settings. However, histopathology remains essential for definitive diagnosis, grading, and subtyping.

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