DOI: https://doi.org/10.53350/pjmhs22163640 ORIGINAL ARTICLE 640 P J M H S Vol. 16, No. 03, MAR 2022 Comparative Study of Histopathological and Immunohistochemical Features of Biopsies of Patients of Lung Cancer SADIA ISLAM 1 , AYESHA ANWAR 2 , SHAMILA TAHIR 3 , ASMA KAZI 4 , AISHA AZIZ 5 , HASSAN FAROOQ 6 1 Assistant Professor Department of Physiology Rashid Latif Medical College Lahore 2 Histopathology resident Combined Military Hospital, Multan. 3 Assistant Professor Pathology Loralai medical college Loralai 4 Associate Professor Medicine Department of Medicine Rashid Latif Medical College 5 Assistant Professor Medicine Department of Medicine Rashid Latif Medical College 6 Assistant Professor. Department of Pharmacology. Allama Iqbal Medical College Lahore, Pakistan. Correspondence to: Sadia Islam ABSTRACT Introduction: When it comes to pollution, smoking, infections, tuberculosis (TB), and allergies, the lungs are the most sensitive organs to damage. Pleural fluid is a fluid that fills the parietal and visceral layers of the pleura that surround the lungs and helps to keep them moist. An investigation of the link between age, gender, and immunohistochemistry findings in lung and pleural biopsy samples was conducted. Materials and procedures: This is a four-year retrospective study that will take place between May 2017 and May 2021. In the current study, a total of 112 cases were submitted for histological investigation, with 100 instances using lung biopsy and 12 cases involving pleural biopsy being the most prevalent. Immunohistochemical testing was carried out as and when it was necessary. Results: A total of 100 lungs were examined. There were 56 cases of neoplastic tumours, 35 cases of non-neoplastic tumours, and nine cases of inconclusive tumours. The most common type of cancer was squamous cell carcinoma. The most prevalent non-neoplastic lesion was angioedema, which was the most common type of lesion (4 percent ). Patients with lung tumours who have malignancy outweigh those who have inflammatory illnesses at our institution. Seven of the 11 pleural biopsy cases were malignant, whereas the other eleven were not. Adenocarcinoma was the most common kind of neoplastic pleural lesion, followed by tuberculosis. Conclusion: The use of histopathology in the diagnosis of lung and pleural lesions is essential. It is possible to increase the accuracy of histological diagnosis with the use of immunohistochemistry. Keywords: Lung biopsy, pleural biopsy, histopathological examination. INTRODUCTION Since years, lung cancer has been the most often diagnosed and most lethal of all cancers. When it comes to cancer-related death 27 percent, lung cancer is the leading cause, with 1.58 million new cases diagnosed each year. Lung cancer is diagnosed at a rate of 1800 new cases each year . Squamous cell carcinoma is most commonly found in the centre of the lungs. These tumours are more likely than adenocarcinomas on the lungs' margins to cause symptoms such as blood coughing sooner in their development. Despite modest advances in treatment over the preceding few decades, lung cancer still has a terrible prognosis in most cases. Pleural diseases, which affect the parietal and visceral pleurae and result in pleural effusions, are classified as follows: Primary parietal pleural malignancies spread to the visceral pleura, whereas metastatic sickness (for example, bronchogenic carcinoma) spreads from the visceral pleura to the parietal pleura (and vice versa). Pleural biopsy offers a greater diagnostic yield and sensitivity than other types of biopsy. Immunohistochemistry also helps to increase the accuracy of diagnostic tests. Biopsy not only distinguishes between benign and malignant lesions, but it also aids in the classification of tumours, allowing for the earlier initiation of specialised therapies such as chemotherapy or surgery. MATERIAL AND METHODS This research was completed in four years . Formalin-fixed lung and pleural biopsy tissues were processed in an automated tissue processor in the instance of 100 patients. The biopsies were subjected to histological examination (H & E stain). The effects of age, gender, and histological morphology were investigated in depth in this study. RESULTS A total of 100 lung and 12 pleural biopsies were taken for the investigation. 72 men and 28 women underwent lung biopsy procedures in a total of 100 patients. There were between 20 and 80 occurrences, with the bulk occurring between 50 and 70 times. The average age was 62.3. Transthoracic and bronchoscopy guided biopsies found 56 neoplastic patients (56 percent) and 63 non-neoplastic patients (63 percent) among the participants.7 instances were malignant (7 percent ). Clinically and radiologically, no malignancy was found in any of the 19 individuals studied. The most common kind of lung cancer was squamous cell carcinoma (29 percent), which was followed by adenocarcinoma 14 percent. Both cancers were seen in male patients. Small cell carcinoma was found in nine more cases in male patients, which was confirmed by immunohistochemical analysis. Interstitial inflammation was the most common non-neoplastic lung lesion, accounting for four percent of all cases (4 percent ). In all, 69 lung samples and 6 pleural biopsies were performed using immunohistochemistry. A patient's age ranged from 35 to 80 years old when they had pleural biopsy. Tuberculosis was the most common non-neoplastic lesion, followed by chronic non-specific pleuritis as the second most common. The majority of malignancies (32.4 percent) occurred in people between the ages of 45 and 75. An adenocarcinoma was the most common malignant tumour in the pleurae, followed by non-small cell lung carcinoma in each of the three male patients who had surgery. It was discovered using immunohistochemistry that the pleural malignancy was an outgrowth of the underlying lung cancer. Fig 1: squamous cell carcinoma of the lung