European Journal of Cardiovascular Medicine

Epididymal lesions are common causes of scrotal swellings, often presenting as nodules or diffuse enlargement. The differential diagnosis includes inflammatory, infectious, cystic, and neoplastic processes. Clinical examination alone is often insufficient to distinguish these entities.

Ultrasonography (USG), particularly with high-frequency probes, serves as the primary imaging modality in scrotal evaluation. It helps in localizing lesions to the epididymis, assessing echotexture, vascularity, and cystic or solid nature. However, overlapping imaging features may limit diagnostic specificity¹.

Fine-needle aspiration cytology (FNAC) is a minimally invasive, cost-effective technique capable of distinguishing inflammatory from neoplastic conditions.²–⁴ When used in conjunction with USG, FNAC enhances diagnostic accuracy, enabling appropriate conservative or surgical management.

This study aims to analyze the cytological spectrum of epididymal lesions, correlate FNAC findings with ultrasonographic characteristics, and evaluate diagnostic accuracy using histopathology as the gold standard.

Study design: Prospective observational study conducted in the Department of Pathology and urology Konaseema institute of medical science Amalapuram ,AP, India from November 2018 to June 2021. Inclusion criteria: Male patients with palpable epididymal swellings or lesions identified on scrotal ultrasonography. Exclusion criteria: Patients with bleeding disorders or unfit for aspiration. Purely testicular or para-testicular lesions. Procedure: All cases underwent ultrasonography using a high-frequency (7.5–15 MHz) linear probe. The following features were documented: Size and location (head, body, tail) Echotexture (homogeneous/heterogeneous) Lesion composition (solid/cystic/mixed) Margins (well or ill-defined) Vascularity (Doppler evaluation) FNAC was performed using a 22–25-gauge needle and 10-mL syringe under aseptic precautions. Air-dried smears were stained with MGG and alcohol-fixed smears with Papanicolaou stain. Ziehl–Neelsen staining was done when granulomatous inflammation was suspected. Histopathology: Excision biopsy or epididymectomy was performed for 25 cases with clinical or cytologic suspicion of neoplasm or tuberculosis. Statistical analysis: Sensitivity, specificity, PPV, NPV, and accuracy were calculated using SPSS v25. Kappa (κ) statistics assessed FNAC-USG agreement. P < 0.05 was considered significant. Ethical clearance: Institutional Ethics Committee approval was obtained (Ref No: IEC/2023/47).

A total of 60 patients with epididymal lesions were evaluated in the present study. The age of the participants ranged from 18 to 72 years, with a mean age of 38.4 ± 12.7 years. Right-sided lesions were slightly more common than left-sided lesions, accounting for 34 cases (56.7%) and 26 cases (43.3%), respectively. The duration of symptoms varied from 1 week to 1 year, with a mean duration of 3.2 months [Table 1].

Table 1: Demographic data

On fine-needle aspiration cytology, tuberculous epididymitis was the most common lesion, identified in 18 cases (30.0%). This was followed by non-specific inflammation in 15 cases (25.0%), sperm granuloma in 10 cases (16.7%), and epididymal cyst/spermatocele in 9 cases (15.0%). Neoplastic lesions were less frequent, with adenomatoid tumor diagnosed in 5 cases (8.3%) and papillary cystadenoma in 3 cases (5.0%) [Table 2].

Table 2: Distribution of FNAC

Ultrasonographic evaluation showed distinct patterns across different lesion categories. Among tuberculous epididymitis cases, heterogeneous echotexture was observed in 16 of 18 cases, increased vascularity in 14 cases, and ill-defined margins in 15 cases. In non-specific inflammatory lesions, 9 of 15 cases showed heterogeneous echotexture and ill-defined margins, while mild vascularity was seen in 8 cases. Sperm granulomas predominantly showed mixed echotexture in 7 of 10 cases, absent vascularity in 9 cases, and well-defined margins in all 10 cases. All cystic lesions demonstrated anechoic appearance, absent vascularity, and well-defined margins. Among neoplastic lesions, 7 of 8 cases appeared as hypoechoic solid lesions, 7 showed increased vascularity, and all 8 had well-defined margins [Table 3].

The correlation of ultrasonographic findings with FNAC diagnosis was highest for cystic lesions, in which concordance was observed in all 9 cases (100%). Concordance was also high in sperm granuloma (9/10; 90.0%) and tuberculous epididymitis (16/18; 88.9%), while it was slightly lower in non-specific inflammation (12/15; 80.0%). The lowest concordance was noted in neoplastic lesions, where agreement was observed in 5 of 8 cases (62.5%). Overall concordance between FNAC and ultrasonography was 85%, with substantial agreement (κ = 0.72, p < 0.001) [Table 3].

Table 3: Ultrasonographic findings

Overall concordance between FNAC and USG: 85% (κ = 0.72, p < 0.001).

Histopathological correlation was available in 25 cases. FNAC demonstrated a sensitivity of 94.1%, specificity of 90.0%, positive predictive value of 94.1%, negative predictive value of 90.0%, and overall diagnostic accuracy of 92.0%. Ultrasonography showed lower diagnostic performance, with sensitivity of 82.3%, specificity of 85.0%, positive predictive value of 87.0%, negative predictive value of 80.9%, and accuracy of 84.0%. The combined use of FNAC and ultrasonography yielded the best diagnostic performance, with sensitivity of 97.0%, specificity of 94.1%, positive predictive value of 96.9%, negative predictive value of 94.4%, and overall accuracy of 96.0% [Table 4].

This indicates that although both FNAC and ultrasonography were useful diagnostic tools in the evaluation of epididymal lesions, FNAC showed superior standalone performance, and the combination of both modalities provided the highest diagnostic accuracy [Table 4].

Table 4: Diagnostic performance compared with histopathology (n = 25)

The present study confirms that FNAC, particularly when interpreted alongside ultrasonography, provides a high diagnostic yield in epididymal lesions. In our series, inflammatory lesions constituted 71.7% of all cases, indicating that inflammatory pathology remains the dominant spectrum of epididymal nodules. This observation is in agreement with earlier cytological studies, which likewise reported a predominance of inflammatory and granulomatous lesions over neoplastic lesions in epididymal aspirates [6,7,10,11].

Tuberculous epididymitis was the most frequent individual lesion in the present study, accounting for 30% of cases. This finding is particularly relevant in tuberculosis-endemic regions, where epididymal tuberculosis continues to represent an important cause of chronic extra-testicular swelling. Previous studies have also highlighted tuberculosis as a major diagnostic category in epididymal FNAC, emphasizing the value of cytology in establishing an early diagnosis and preventing unnecessary surgical intervention [9,10,12]. The demonstration of acid-fast bacilli on Ziehl–Neelsen staining in 10 of our cases further strengthened the diagnosis and illustrates the utility of ancillary staining in granulomatous epididymal lesions [9].

Sperm granuloma constituted 16.7% of the lesions in this study. Cytologically, these lesions were characterized by the presence of spermatozoa, multinucleated giant cells, and an inflammatory background, allowing confident distinction from neoplastic processes. Similar benign reactive lesions have been documented in earlier FNAC series of epididymal nodules, underlining the practical role of aspiration cytology in avoiding overtreatment of clinically suspicious but non-neoplastic masses [6,10,12].

Among neoplastic lesions, adenomatoid tumor was the most common benign neoplasm, comprising 8.3% of cases. This is consistent with previous literature showing that adenomatoid tumor is the commonest benign tumor of the epididymis. On ultrasonography, these tumors generally appear as well-circumscribed extra-testicular nodules, but imaging findings alone are often not entirely specific. Hence, cytological confirmation becomes especially useful in differentiating benign epididymal tumors from lesions that may require more aggressive management [7,11].

In the present study, ultrasonography alone achieved a diagnostic accuracy of 84%, FNAC alone yielded 92% accuracy, and the combined use of both modalities improved diagnostic precision to 96%. These findings strongly support the complementary roles of imaging and cytology in the evaluation of epididymal lesions. Ultrasonography is highly effective in localizing lesions and confirming their extra-testicular origin, whereas FNAC provides direct morphological diagnosis. Recent evidence also supports that the diagnostic performance of FNAC improves further when correlated with ultrasonographic findings [8,11,12].

The principal limitations of the present study were the relatively small sample size and the lack of histopathological follow-up in some benign lesions. In addition, advanced sonographic techniques such as elastography and contrast-enhanced ultrasonography were not utilized. Nevertheless, the present findings reinforce that FNAC, when combined with ultrasonography, is a safe, rapid, minimally invasive, and cost-effective approach for the diagnosis of epididymal lesions, especially in resource-limited settings.

FNAC is an accurate, safe, and minimally invasive technique for evaluating epididymal lesions. When interpreted alongside ultrasonographic findings, it provides near-definitive diagnosis in most cases, reducing unnecessary surgical interventions. Combined FNAC-USG correlation should be the standard approach for evaluation of epididymal swellings.

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