Fine Needle Aspiration Cytology (FNAC) is the study of cells extracted from within organs, tumor nodules or other tissues. FNAC was first used by Martin and Ellis as a diagnostic tool.¹ It is a basic, generally safest, fast, trustworthy strategy for the diagnosis of lung lesions, especially with the guide of Ultrasonography (USG) or Computed tomography (CT) scan.

Lung lesions include a variety of benign and malignant conditions. Benign lesions include acute inflammatory lesions (abscess), granulomatous inflammation caused by mycobacterium bacilli, fungal infections and nonspecific chronic inflammatory lesions caused by several pathogens. Most malignant lesions that start in the lung, known as primary lung cancers, are carcinomas that derive from epithelial cells.² According to WHO, lung carcinoma is the second most common cancer worldwide (2.21 million cases) and is the most common cause of cancer deaths (1.80 million deaths). In India, lung cancer accounts for 5.9% of all cancers and 8.1% of all cancer-related deaths. The main primary types are small-cell carcinoma (SCC) and non-small-cell carcinoma (NSCC). NSCC is no longer an adequate diagnostic category. Pathologists are required to further classify NSCC into adenocarcinoma and squamous cell carcinoma since specific therapies are now recommended depending on the tumor type. Lung is also a well-known site for metastasis of other tumors.

Treatment and long-term outcomes depend on the type of cancer, the stage (degree of spread), and the person’s overall health.²

Ultrasonography (USG) or Computed tomography (CT) guided fine needle aspiration cytology (FNAC) is often an effective and safe way to obtain the diagnostic material of lesions located in lung.  FNAC plays an integral part in recognizing benign and malignant lesions and aids in typing of lung cancers to start particular treatment like chemotherapy or surgery immediately.³

Most common complications of USG or CT guided FNAC are pain, hemorrhage, nausea and vomiting. However, due to cost effectiveness and less time consumption, these procedures are increasing in trends.⁴ The rate of pneumothorax varies from 6% to 57% from which 1.5 to 20 % require intercostalcatheterization.⁵ Examples of neoplastic implantation along a thoracic needle track have been reported.⁶

Haemorrhagic diathesis and anticoagulant therapy are contraindications to lung FNAC, and the prothrombin time and the platelet count should be checked before FNAC. Patients who do not have a cough reflex, who are unconscious or who cough intractably should not be biopsied. Most authors do not recommend FNAC of suspected hydatid cyst cases due to the possibility of an anaphylactic reaction to leaking cyst fluid or implantation of germinal epithelium. However, when aspiration of unsuspected cyst occurs, complications are very few.⁷ Concurrent bilateral lung biopsies are also not recommended.⁸

The patient should be kept under observation for a few hours after FNAC to monitor pulse, blood pressure and chest pain.

The purpose of this study was to assess the utility of guided FNAC in diagnosis of lung lesions and to classify them as benign, malignant, suspicious or inflammatory. This study helped in early detection and management protocol of lung lesions.

This is a cross-sectional study which was carried out in the Department of Pathology, Government Medical College, Kota for a period of 18 months from December 2022 to May 2024. Patients of all age groups from M.B.S. Hospital and New Medical College Hospital Kota, in whom FNAC of lung lesions was advised were the study subjects. Total 113 patients were included in the study.

Patient with suspected bleeding diathesis, on anticoagulant medication, who do not have a cough reflex and who were unconscious were excluded from study.

Each case was subjected to a detailed history, thorough clinical examination, routine haemogram, prothrombin time and/or platelet count (where necessary) and imaging (USG/CT).

The procedure, risk and benefits were explained to the patient before aspiration and informed written consent was taken. The skin at the proposed site of puncture was cleaned with spirit. USG or CT localization of the lesion was done. A 22 gauge, 90 mm disposable lumbar puncture needle with trocar was placed against the skin at the predetermined puncture site and inserted into the lesion under USG/CT guidance with a single quick motion. Once the needle is in the lesion, the trocar was removed and a 10 ml disposable plastic syringe was attached to the needle. The plunger of the syringe was retracted to create negative pressure in the syringe and the needle lumen. This draw material in the needle. The needle was moved back and forth several times. Constant negative pressure was maintained in the syringe throughout this manipulation by keeping the plunger of the syringe retracted. As the material started coming in the needle hub, the aspiration was completed. The pressure in the syringe was allowed to return to atmospheric pressure by gently releasing the plunger. The aspirated material remained in the needle. The needle was withdrawn from the lesion and pressure applied on the puncture site with spirit-soaked cotton/ gauze. Needle was detached and air was drawn into the syringe. Needle was attached again and aspirate was blown onto clean glass slides. Smears were immediately made by applying a gentle pressure with another slide and then air dried. Air dried smear slides were fixed with methanol for 15-20 minutes. Then the slides were transferred to the coplin jar containing giemsa stain, freshly diluted with 9 volumes of buffered water (pH 6.8) for 10-15 minutes. After that step, the slides were transferred to the buffered water (pH 6.8) with rapidly washing in 3 to 4 changes of water. The slides were kept upright to dry and mounted with coverslip.

In this study, majority of the patients were in the age group 61-80 years with 73 patients (64.60%) followed by age group 41-60 years with 36 patients (31.86%) and age group 81-100 years with 3 patients (2.65%). There was 1 patient (0.88%) in age group 21-40 years. There was no patient in the group 0-20 years. The average age of study group was 63.65 years. The youngest patient aged 27 years and oldest aged 87 years.

In this study male patients were 91 (80.53%) and female patients were 22 (19.47%). Male to female ratio was 4.14: 1.0.

In this study, 87 patients (76.99%) were smokers, and 26 patients (23.01%) were non-smokers. Ratio of smokers to non-smokers was 3.35:1.0. Among the smokers 81 patients (93.10%) were males and 6 patients (6.89%) were females.

In this study, right side of lung was involved in 70 patients (61.95%) and left side of the lung was involved in 43 patients (38.05%). The most common lobe involved was right upper lobe with 33 patients (29.20%) followed by equal involvement of right lower lobe and left upper lobe with 23 patients (20.35%), left lower lobe in 20 patients (17.69%) and right middle lobe in 19 patients.

Most of the patients presented with multiple complaints but the most common presentation was cough affecting 87 (76.99%) out of 113 patients followed by chest pain affecting 63 patients (55.75%), weight loss affecting 60 patients (53.10%), dyspnoea affecting 59 patients (52.21%) and fever affecting 38 patients (33.63%). 16 patients (14.16%) complained of haemoptysis, 7 patients (6.19%) complained of back pain, 3 patients (2.65%) complained of hoarseness of voice, 3 patients (2.65%) complained of hemiparesis, 1 patient complained of amnesia and 1 patient facial palsy.

Adequate sampling material was obtained in 99 patients (87.61%) out of 113 patients. These patients were evaluated for cytomorphological characteristics. Out of 99 patients, 79 (79.79%) diagnosed as malignant lesions  and 20 (20.20%) diagnosed as benign lesions.

14 patients (12.39%) were excluded from study for further calculations due to inadequate sampling material after repeated aspirations.

The most common lesion diagnosed on cytology was adenocarcinoma in 29 patients (29.29%) followed by squamous cell carcinoma in 27 patients (27.27%), small cell carcinoma in 12 patients (12.12%) and poorly differentiated carcinoma in 5 patients (5.05%). 6 patients (6.06%) were reported as suspicious for malignancy due to low cell yield with presence of atypical cells. 11 patients (11.11%) were diagnosed as non-specific inflammatory pathology, 7 patients (7.07%) were diagnosed as tubercular pathology, 1 patient (1.01%) was diagnosed as benign cystic lesion and 1 patient (1.01%) was diagnosed as fungal pathology.

The diagnostic accuracy of USG/CT guided FNAC in the present study was calculated to be 87.61% using cytology as the gold standard.

In this study 6 patients complained of chest pain following the procedure. No major complications were encountered in the study.

Figure-1: Adenocarcinoma. Cytosmear shows cluster of malignant cells, cells are of moderate to large size having moderate to abundant amount of cytoplasm, round eccentric nuclei, clumped chromatin with prominent nucleoli. (MGG, 400x)

Figure-2:  Keratinizing squamous cell carcinoma. Cytosmear shows dispersed keratinizing squamous cells having moderate amount of blue cytoplasm, pleomorphic hyperchromatic nuclei against a background containing necrotic debris and neutrophils. (MGG, 100x)

Figure-3: Non-keratinizing Squamous cell carcinoma. Cytosmear shows cells in irregular solid cohesive fragment with moderate amount of cytoplasm, elongated or spindle shaped hyperchromatic nuclei. (MGG, 200x)

Figure-4: Small cell carcinoma. Cytosmear shows small to medium-sized cells in clusters with little or no cytoplasm, nuclear molding, uniform finely granular nuclear chromatin. (MGG, 400x)

Figure-5: Poorly differentiated carcinoma. Cytosmear shows poorly differentiated atypical cells. (MGG, 400x)

Figure-6: Suspicious for malignancy. Cytosmear shows scanty cellularity with few atypical cells with enlarged hyperchromatic nuclei. (MGG, 400x)

Figure-7: Nonspecific inflammatory pathology. Cytosmear shows plenty of polymorphs with macrophages and necrotic background. (MGG, 200x)

Figure-8: Epithelioid cells forming Granuloma. (MGG, 200x)

Figure-9: Cystic lesion. Cytosmear shows macrophages and polymorphs. (MGG, 200x)

Figure-10: Fungal pathology. Nonseptate, ribbon-like fungal hyphae showing right-angled branching at places. (MGG, 200x)

Lung cancer is the leading cause of cancer-related deaths worldwide. According to Global cancer statistics 2018, lung cancer accounts for 8.1% of all cancer related deaths in India. Transthoracic fine needle aspiration cytology using USG/CT guidance is the most often used technique for the diagnosis of lung lesions. It enables categorization of benign and malignant lesions and helps in early and proper management of the patient.

The present study was carried out to study the cytomorphology of lung lesions. A total number of 113 patients were included in this study and adequate sampling material was obtained in 99 patients.

In this study, the average age of presentation of lung lesions was 63.65 years with male predominance.

Similar average age of presentation was found in the study done by Wallace MJ et al. (2002)⁹ with slight differences in studies done by Gangopadhyay M et al. (2011)¹⁰ and Chakrabarti PR et al. (2020)¹¹. This indicates that lung lesions especially malignant lung tumours come to clinical attention at middle to old age. Dissimilarities in average age of presentation were observed in studies done by Baby J et al. (2014)¹² and Ahmed Z et al. (2018)¹³ with early age of presentation. The differences may be due to literacy, better health facilities and early presentation of the patients.

In the present study the male preponderance noted is consistent with the studies done by Wallace MJ et al. (2002)⁹, Gangopadhyay M et al. (2011)¹⁰, Baby J et al. (2014)¹² and Ahmed Z et al. (2018)¹³, Chakrabarti PR et al. (2020)¹¹. The male predominance may be due to higher incidence of predisposing factors like chronic obstructive pulmonary disease, smoking and alcoholism in males.

In this study, 87 patients (76.99%) were smokers, and 26 patients (23.01%) were non-smokers. A strong association (76.99%) was found between the lung lesions and tobacco smoking history. Biswas P et al. (2016)¹⁴ and Pant P et al. (2020)³ also found a strong association between smoking history and lung lesions.

In the present study cough was the most common complaint found in 76.99% cases followed by chest pain in 55.75% cases, weight loss in 53.10% cases, difficult breathing in 52.21% cases and fever in 33.63% cases. Similar chief complaints were found in studies done by Gangopadhyay M et al. (2011)¹⁰, Biswas P et al. (2016)¹⁴, Srivastava S et al. (2018)¹⁵, Pant P et al. (2020)³.

In our study adequate sampling material was obtained in 99 patients (87.61%). Out of these 99 cases, 20.20% were inflammatory or benign conditions and 79.80% were malignant lesions. Our findings were similar to studies done by Saha A et al. (2009)¹⁶, Gangopadhyay M et al. (2011)¹⁰, Piplani S et al. (2014)¹⁷, Biswas P et al. (2016)¹⁴, Ahmed Z et al. (2018)¹³ and Chakrabarti PR et al. (2020)¹¹.

The higher percentage of malignant lesion in this study and in other studies is probably due to treatment of inflammatory conditions by antibiotics whereas malignant and tubercular cases are non-responsive to antibiotics and have chronic symptoms that comes to diagnosis by USG/ CT-guided FNAC.

In this study, the incidence of adenocarcinoma was higher than squamous cell carcinoma. This was in concordance with the study done by Gangopadhyay M et al. (2011)¹⁰, Piplani S et al. (2014)¹⁷, Biswas P et al. (2016)¹⁴. However, in the study done by Saha A et al. (2009)¹⁶, Ahmed Z et al. (2018)¹³ and Chakrabarti PR et al. (2020)¹¹ squamous cell carcinoma was found to be the leading primary malignant neoplasm. This difference may be due to the rising trend of adenocarcinoma in our state.

The diagnostic accuracy of USG/CT guided FNAC in the present study was found to be 87.6% based on the cytology as gold standard test for diagnosis of lung lesions. This was comparable with the studies done by Piplani S et al. (2014)¹⁷ and Baby J et al. (2014)¹².

Complications of transthoracic fine needle aspiration cytology reported by various researchers were comprised of pain at puncture site, pneumothorax, pulmonary haemorrhage, haemoptysis, implantation of malignant cells in the needle tract, bleeding into the chest wall. Pneumothorax is the most common complication with the occurrence rates varying from 3 to 57% with 2-17% patients requiring a chest tube.35,36

In the present study, no major complications were noted, only 6 patients developed chest pain following the procedure.

Conclusion of this study showed that USG/CT guided FNAC is a safe, quick and minimally invasive procedure with a good diagnostic accuracy for the evaluation of lung lesions. It provides early diagnosis and sub-classification of various lung lesions based on cytomorphological features. It helps to formulate immediate and proper management of lung lesions.

1. Martin HE, Ellis   Biopsy by needle puncture and aspiration. Ann Surg.  1930 Aug;92(2):169-81.
2. Modi MB, Rathva MR, Shah NR, Trivedi M, Patel H. Role of FNAC in lung carcinoma and its histocytological correlation. J Lung Plume Respir Res. 2016;3(4):109-12.
3. Nair A, Aniudh S, Moorthy S, Cyril P, Mangalath RB, Ramachandran PV. CT-guided lung fine needle aspiration biopsy: Analysis of efficacy, yield and intricacies. Indian J Med Paediatr Oncol. 2018;4:178-83.
4. Dosi S, Gupta G, Kawatra M, Chakrabarti PR, Agarwal P, Jain MR. Role of radiological assisted cytology in intra abdominal lesions: A 3 years experience in a tertiary care center. Int J App Basic Med Res. 2016;6:101-5.
5. Sterrett G, Whitaker D, Glance J. Fine needle aspiration of lung mediastinum and chest wall. Pathol Annu. 1982;17(Part 2):197-228.
6. Sinner WN, Zajicek J. Implantation metastasis after percutaneous transthoracic needle aspiration biopsy. Acta Radiol Diagn (Stockh). 1976;17:473-80.
7. Das DK, Bhambhani S, Pant CS. Ultrasound guided fine needle aspiration cytology: diagnosis of hydatid disease of the abdomen and thorax. Diagn Cytopathol. 1995;12:173-6.
8. Orell SR, Sterrett GF. Orell & Sterrett’s Fine Needle Aspiration Cytology: Lung, chest wall and pleura. 5^th London; Churchill Livingstone Publ: 2012. P. 21.
9. Wallace MJ, Krishnamurthy S, Broemeling LD, Gupta S, Ahrar K, Morello FA Jr, Hicks ME. CT-guided percutaneous fine-needle aspiration biopsy of small (< or =1-cm) pulmonary lesions. Radiology. 2002 Dec;225(3):823-8.
10. Gangopadhyay M, Chakrabarti l, Ghosh N, Giri A. Computed tomography guided fine needle aspiration cytology of mass lesions of lung: our experience. Indian Journal of Medical and Paediatric Oncology. 2011;32(4):192-96.
11. Chakrabarti PR, Chakraborty K, Kukreja P. Role of image-guided fine needle aspiration cytology of lung lesions in diagnosis and primary care of patients: Experience in a government Medical College of Eastern India. J Family Med Prim Care. 2020 Jun 30;9(6):2785-88.
12. Baby J, George P. Computed tomography guided fine needle aspiration cytology of thoracic lesions: A retrospective analysis of 114 cases. IOSR Journal of Dental and Medical Sciences. 2014 Jan;13(1):47-52.
13. Ahmed Z, Israt T, Raza AM, Hossain SA, Shahidullah M. CT guided FNAC of lung mass- A retrospective study of disease spectrum. J Histopathol Cytopathol. 2018;2:109-13.
14. Biswas P, Datta A, De A, SinhaLK. Pulmonary Mass Lesions: CT Scan Diagnostic-Impressions and FNAC Diagnoses – A Correlative Study. Int J Med Res Rev [Internet]. 2016 Jun.30;4(6):1052-6.
15. Srivastava S, Bajaj S. Ultrasonogram-guided fine needle aspiration cytology in peripheral lung lesions. Int J Contemp Med Surg Radiol. 2018;3(1):60-4.
16. Anupam S, Kshitish K, Manoj KC. Computed tomography-guided fine needle aspiration cytology of thoracic mass lesions: A study of 57 cases. J Cytol. 2009;26:55-88.
17. Piplani S, Mannan R, Lalit M, Manjari M, Bhasin TS, Bawa J. Cytologic-Radiologic Correlation Using Transthoracic CT-Guided FNA for Lung and Mediastinal Masses: Our Experience. Analytical cellular pathology (Amsterdam). 2014;2014:3434