Pathological Spectrum of Lung Lesions: A Study Done on Surgical Lobectomy Specimens

Background: Lung cancer is by far the leading fatal cancer in both men and women, compared to prostate, colon and rectum. Both the neoplastic lesions and non-neoplastic lesions (obstructive and restrictive pulmonary diseases and occupational lung diseases) cause significant morbidity.

Aims: The aims are to study the spectrum of non-neoplastic and neoplastic lesions of the lung and to study the incidence of lung cancers with reference to age, gender, lifestyle and occupation.

Materials and Methods: This is a retrospective observational study done over a period of 2 years (May 2009 to April 2011) in the Department of Pathology, GGH, Guntur. A total of 52 lobectomy specimens were studied. Formalin-fixed, paraffin-embedded H & E stained tissue sections were studied. Special stains (Gomorri’s methenamine silver stain and Periodic acid Schiff) were done whenever necessary. Immunohistochemistry was done in diagnostically difficult cases. Multistep procedure (sandwich method) was followed using a biotinylated universal secondary antibody and a third layer of streptavidin, horse radish peroxidase complex and finally 3,3'-Diaminobenzidine (DAB) chromogen was used to develop colour at the site of antibody binding.

Results: Neoplasms constituted 38.4% of total lobectomy lesions. The majority of lung tumors occurred in the fifth and sixth decades. The Male-Female sex ratio was 4:1. On chest x-ray/CT scan chest, the majority of lung tumors presented as mass lesions. The right side of the lung was more commonly affected than the left. Cigarette smoking was the major etiological factor in the causation of lung carcinomas. Among the primary tumors, adenocarcinoma constituted the largest group followed by squamous cell carcinoma. One case of synchronous lung tumor is reported in the study in a 60-year-old male patient while one case of pulmonary hydatid cyst is reported in an 11-year-old female patient.

Conclusion: From the present study, it is concluded that adenocarcinoma is now the most common lung carcinoma in all races and sex groups. There was a strong association between lung cancer and smoking. Chest radiographs and CT scan aid in the diagnosis and anatomical localisation of lung tumor. Tuberculosis was the most common infection of the lung in both males and females