Dr.Ergete, Wondwossen (MD), Associate Professor of Pathology:Kassa, Amanuel2021-03-072023-11-052021-03-072023-11-052020-12http://etd.aau.edu.et/handle/123456789/25290Background: List of disease entities affect the lung, with surgically removed masses accounting a large share in proportion. A variety of neoplastic and non-neoplastic lesions are under this category. Results of several studies show neoplastic lesions account for the largest share among resected specimens. From the neoplastic lesions, malignancies are the most common ones; from these primary tumors (carcinomas) are the leading. Benign tumors are very rare compared to the malignant ones, hamartoma being the most common among the benign category. According to the 2018 WHO report, lung cancer is the most cancer (2.09 million cases) and the leading cause of death (1.76 million). According to the Globocan report on the incidence and prevalence of cancer in Ethiopia by 2018, Lung cancer ranks the 7 most common malignancy in Ethiopia. Addis Ababa population-based pattern of cancer therapy, found out that lung cancer ranking as the 5th most common malignant tumor. Objectives: The aim of this study was to determine the frequency and histopathologic patterns of lung lesions with clinicoradiological features in resected specimens diagnosed in Tikur Anbessa Hospital. Methods and materials: Retrospective study was conducted on five years biopsy reports of neoplastic and non-neoplastic resected lung lesions submitted from January 01, 2016 to August 30, 2020. Data had been retrieved from the archive of the department of pathology. Clinical presentation and gross description of the lesions was collected from the patient’s original biopsy request. Final data analysis was done using latest SPSS version 25. Results: From a total of 170 cases reviewed 159 cases fulfilled the study criteria and included in the study. From these, 99 (62.3%) of the study subjects were males while the remaining 60 (37.7%) were female. M:F ratio of 1.65:1. The minimum age was 2 month and the maximum age was 73 year. Mean age of patients was 36.8 year. There were 92 (57.9%) non-neoplastic cases and 67 (42.1%) neoplastic cases. The commonest age group for both neoplastic and nonneoplastic lesions were 3rd and 4th decades. Cough and hemoptysis were the commonest clinical presentation (n = 39, 24.5%). The commonest radiologic finding was mass 37 (23.3%). Lobectomy was the most common surgical procedure performed (n=97, 61 %) followed by pneumonectomy 38 (23.9%). Bronchiectasis was the most common non-neoplastic histopathologic entity 18 (11.3%) cases, followed by aspergillosis 16 (10.1%) cases. Out of the 67 neoplastic cases, only 5 (7.5%) cases were benign the rest 62 (92.5%) were malignant. All the benign tumors were hamartoma. The malignant cases had a M:F ratio of 1.06:1. Typical carcinoid was the most common histopathologic type reported (45.2%), followed by adenocarcinoma (25.8%), SCC (9.7%). Majority of the malignant neoplasms were in pathologic stage II (55.2 %). There were 31 (53.4%) cases with known lymph node status. From these, 58.1 % had up to 3 LNs and 25.8 % had up to 4-6 LNs examined with majority had N0 (34.5%) cases and N1 (15.5%) cases. Conclusion: In this study a higher proportion of non-neoplastic lesions were identified in resection specimens than neoplastic cases. Carcinoid tumor was the most frequent histopathologic subtype. then-USHistopathologic, neoplastic , non-neoplastic LungThesis