Small Pulmonary Lesions -A Challenge for Thoracic Surgery?

We analyzed the diagnosis, the potentially associated external and clinical features, and the surgical procedures of small pulmonary lesions, especially hamartomas (in relation to peripheral T1 lung carcinomas and lymphoid hyperplasia) in 103 patients who experienced enucleation or resection of pulmonary hamartomas between March 1, 1995 and December 31, 2000. The causes of surgical intervention, presurgical diagnoses, surgical procedures, location, size, and histological compartments were analyzed, as well as clinical features potentially associated with the tumors (alcohol, asbestos, smoking, and chronic lung diseases). Follow up of patients lasted for 5.5 years at maximum. For comparison, 36 patients with peripheral T1 lung carcinomas are included as well as 50 patients with lymphoid hyperplasia. The sex and age distribution of the patients with hamartomas was comparable to that of patients with lymphoid hyperplasia. About 75% of men and 55% of women were heavy smokers, with an average history of 30 and 17 pack years, respectively. In 84% of patients, the lesions were incidentally detected in chest radiographs, whereas 12% of patients underwent thoracic surgery suspicious for intrapulmonary metastases of known extrapulmonary malignancies. Enucleation was performed in 21%, and wedge resection in 77% of patients. At average, hamartomas were smaller than T1 lung carcinomas, but considerably larger in comparison to lymphoid hyperplasia. No recurrent tumors or additionally detected hamartomas were noted during the follow up, and both surgical procedures (enucleation or wedge resection) were identical in curative treatment. All patients with peripherally localized T1 tumors underwent lobectomy. The 3/5 year survival rate was calculated to 69/52%. Lymphoid hyperplasia is of clinical importance for the estimation of prognosis in patients with metastatic disease, as the number of radiologically suggestive metastatic nodules can often be significantly changed due to this entity. Pulmonary hamartomas are benign lesions that display certain clinical associations with malignant lung carcinomas in respect to external risk factors, and to lymphoid hyperplasia. Both surgical procedures (enucleation or wedge resection) can be performed, giving identical results in respect to treatment. KEY WORDS: pulmonary hamartoma, T1 carcinoma, lymphoid hyperplasia, diagnosis, surgical treatment, prognosis DOMAINS: pulmonology, clinical trials, cancer Kayser et al.: Thoracic Surgery for Pulmonary Lesions TheScientificWorld (2001) 1, 906-913 907 INTRODUCTION Benign tumors of the lung are rare, comprising only about 5% of all intrapulmonary tumors Hamartomas seem not to possess striking clinical or surgical features at a first glance; however, they are interesting lesions in respect to their origin and their biological behavior. It is still in question whether these lesions are of neoplastic origin, or whether they are just chronic inflammatory lesions with some specific abnormalities mimicking a neoplasm Our prospective study was designed primarily to contribute to chromosome analysis of deepfrozen hamartomatous tissue. It soon became clear that clinical features, patient behavior, and prognosis might make an equally important, if not superior, contribution to the increase of knowledge of this rare entity of a benign lung lesion. MATERIAL AND METHODS This prospective study started March 1, 1995 and includes all patients with surgically excised pulmonary hamartomas treated at the Thoraxklinik, Heidelberg, until December 31, 2000. A total of 103 patients were included, of whom 45 underwent a preoperative transbronchial biopsy. A definitive diagnosis could not be obtained by these preoperative investigations, probably due to sampling errors (i.e., missing the lesion). For comparison, a contemporary prospective study including 36 patients with radiologically comparable lesions (staged T1 N0) resulting in histologically proven primary lung carcinomas was included in this analysis. The third cohort comprises 50 patients with peripheral lesions suspicious for malignancy or metastatic growth, and histologically confirmed as lymphoid hyperplasia. The diagnosis in all cohorts is based on Kayser et al.: Thoracic Surgery for Pulmonary Lesions TheScientificWorld (2001) 1, 906-913 surgical specimens only, and includes common HE stains, PAS, and Feulgen stains. The history of the patients was analyzed, with specific attention given to smoking and alcohol consumption. Information about surgical procedures, potential side symptoms, and the presence of other diseases was obtained from the intraoperative reports. The clinical trial was determined January 31, 2001. Survival was evaluated by repeated questionnaires sent to the house physicians. The statistical analysis was performed using a commercially available package (Number Cruncher Statistical System, NCSS, Kaysville, UT). 908 RESULTS A total of 103 patients with hamartomas were included in this study, including 61 men and 42 women