Studies of malignant & non-malignant lung lesions detected by USG guided FNAC in the Saurashtra region

Introduction

USG Guided fine needle aspiration cytology (FNAC) is a pivotal diagnostic tool for evaluating both malignant and non-malignant lung lesions. This minimally invasive procedure by using ultrasound accurately guide a fine needle to the targeted lung lesion.1, 2 FNAC is particularly valuable in distinguishing between benign conditions, such as inflammatory or infectious lesions, and malignant entities, including various types of lung carcinoma. By obtaining cellular samples from the lesion, FNAC provides crucial diagnostic information, aiding in appropriate treatment planning and management. Its precision and effectiveness make it an essential component in the diagnostic workup of lung lesions.3, 4 Peripheral lesions, where bronchoscopic brush and lavage preparation is not useful, FNAC is very much useful.5

Materials and Methods

A study was conducted in the Pathology Department of P.D.U. Medical College & Hospital. Over the course of a year, from November 2021 to October 2022, data from 58 patients undergoing USG Guided FNAC at P.D.U. Hospital were analyzed. Most cases referred to our institute originated from the clinical departments, specifically the respiratory medicine ward. USG Guided FNAC was performed following an explanation of risks and benefits and obtaining informed written consent from each patient. FNAC was carried out using a 22–24-gauge needle with a 10 ml syringe for superficial masses and a 9-cm, 20–22-gauge spinal needle for deeper lesions. The glass slides with spread material were immediately fixed in 95% alcohol for H&E staining and mounted in DPX. Some slides with air-dried material were also prepared for MGG staining. Post-procedure pneumothorax was closely monitored by a respiratory medicine doctor at the procedure site to ensure prompt management and patient safety.

Result

Fine Needle Aspiration Cytology (FNAC) was performed under USG guidance. Out of 58 patients, 5 required a repeat FNAC. A definitive diagnosis was achieved in 54 cases. Patient ages ranged from 30 to 90 years, with the majority presenting symptoms in their 50s (44.83%) and 60s (29.31%). The youngest patient diagnosed with bronchogenic carcinoma was 39 years old. No cases were reported in the below 20-year age groups during this study.

Males comprised the majority of patients presenting with signs and symptoms, with an incidence rate of 79.31%.

Female patients had an incidence rate of 20.68%, leading to a male-to-female ratio of 3.8:1.

Out of 46 male patients 38 patients had given positive history for smoking which is showing incidence rate of 82.60% and out of 12 female patients 2 patients were giving positive history for smoking (16.66%). 83.33% of female subjects were non-smoker and 17.40% of male subjects were non-smoker. Out of 46 male 38 were smoker and malignancy were diagnosed in 33 cases. Out of 12 female 02 were smoker and malignancy were diagnosed in 01 cases.

Majority of the patients had presented with chief complain of cough (77.59%), Chest Pain (44.83%) and followed by weight loss (32.76%), anorexia (31.03%), expectorant (17.24%), anorexia (31.03%) along with others 20.69% case was a history of TB. In the above-mentioned table only one main presenting symptom of the patient has been considered. Patients were having associated other symptoms also.

Majority of the patients had presented with consolidation & mass lesion which was found in 19& 13 respectively patients out of 48 patients. Cavitary lesions were found in 15 patients among which only one case was diagnosed as Horner syndrome, Pleural effusion was noted in 06 patients out of which 04 patients were having associated malignant lesion whereas only one patient was diagnosed as tuberculosis was having cavity.

Graph 1

Distribution showing side and site of the lesions (58 Cases)

Lesions were more localized on Right side of Lung (39 patients) compared to Left side (19 patients) in the present study. Upper & Middle zone (26&10 respectively) lesions were more on both sides than lower zone (15 patients) lesions.

Out of the 58 cases, A malignancy was identified in 43 cases: 21 patients were diagnosed with the highest incidence being squamous cell carcinoma (36.20%). Adenocarcinoma was detected in 15 patients (35.86%), while 1 patient had large cell carcinoma one had small cell carcinoma and one had carcinoid tumor. Among non-malignant lesions, there was 1 inflamed cystic lesion, 11 cases of inflammatory lung lesions, 1 case of tuberculosis, and 1 case of fungal inflammation.

Figure 1

Squamous cell carcinoma demonstrating high N:C Ratio and Hyperchromatic Nuclei (H & E, 40X).

Figure 2

Adenocarcinoma showing glandular cell clusters with intranuclear cytoplasmic inclusions (Giemsa Stain, 10X)

Figure 3

Small cell lung carcinoma exhibiting small clusters with minimal cytoplasm, finely granular chromatin, and nuclear molding (H & E, 40X)

Figure 4

Aspergillosis in lung highlighting hyphae branching at 45 degrees (H & E, 40X)

Figure 5

A): Epithelioid Granuloma, B): Caseation in FNAC, C): Acid-Fast Bacilli Stained with Auramine-Rhodamine (H & E, 40X; Auramine-Rhodamine, 100X)

Discussion

Fine Needle Aspiration Cytology is a reliable and precise method for diagnosing and categorizing benign, malignant, and inflammatory lesions, and it is a well-established diagnostic procedure for both primary and secondary lung carcinomas.

Studies of FNAC have included all age groups from 8 to 90 years.6, 7, 8, 9 In the present study, the ages of patients ranged from 21 to 90 years, with pulmonary neoplasms being most prevalent in the 5th and 6th decades (31.03% and 38.79%, respectively). Similar findings were observed by Agarwal et al.11 The male-to-female ratio of 3.8:1 in our study was comparatively higher than in other studies, consistent with the findings of Cristallini et al.12 (3.8:1) and Gouliamos et al.13 (3.6:1)

Among the 97 male patients, 75 were smokers, with malignancy diagnosed in 56 cases. Among the 19 female patients, 5 were smokers, with malignancy diagnosed in 3 cases. The incidence of smoking was 62.06%, comparable to the findings of Bhattacharya et al.6 and Jalpa et al.9

Most of the lung cancer patients (63.79%) presented with complaints of cough, similar to the findings of Ghosh et al.14 (71.2%) and Jalpa et al.9 (55.8%). In the present study, 58 cases were classified as suspected malignant lesions [due to the unavailability of IHC (Immunohistochemistry) and molecular diagnostic workups]. Lung cancer were aspirated, with 43 found to be malignant and 15 benign. The most common malignancy was squamous cell carcinoma (36.20%), followed by adenocarcinoma (25.86%), small cell carcinoma (1.72%), and large cell carcinoma (1.72%), and 4 case was suspected of metastatic (6.89%). Which aligns closely with the studies conducted by Upal et al.,10 Parate et al.,15 Wallace et al.,16 and Dahistrom et al.17

Conclusion

With advancements in imaging techniques such as USG guidance, Fine Needle Aspiration Cytology (FNAC) has become a highly effective tool for diagnosing small lung lesions. These imaging modalities enhance the accuracy of FNAC, enabling precise identification of clinically and radiologically suspected lung tumors. Modern cytology benefits from refined cytomorphological criteria, making tumor diagnosis and typing more straightforward. The quality of the material obtained through FNAC facilitates cell block preparation and allows for the application of special stains and markers, further aiding in the confirmation of diagnoses.

Source of Funding

None.

Conflict of Interest

None.

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