Preoperative cytodiagnosis of very small-sized peripheral-type primary lung cancer

To demonstrate the importance of preoperative diagnosis of pulmonary cancers presenting as peripheral small-sized solitary shadows we evaluated the results of morphologic definitive diagnosis together with various clinical factors in 91 tumors with less than 15-mm diameter resected surgically between 1983 and 1999. Histologically, these tumors consisted of 73 adenocarcinomas, nine squamous cell carcinomas, and nine other types. Regarding the pathologic stage, 57 tumors were classified in stage IA, three in IB, six in IIA, seven in IIIA, 14 in IIIB, and four in IV. Comparing various biopsy techniques, the sensitivity of preoperative cytodiagnosis was 43.7% for transbronchial brushing (n = 48), 52.9% for transbronchial forceps biopsy-stamp cytology (n = 51), 66.6% for transbronchial fine needle aspiration (n = 78), and 85.0% for percutaneous fine needle aspiration (n = 20). The overall sensitivity of preoperative cytodiagnosis was 79.0% for transbronchial biopsy (n = 81), and 87.3% for transbronchial and percutaneous biopsy (n = 87). Of 73 clinical N0 cases in which lobectomy was performed, 10 cases (13.6%) were diagnosed as between pathological degrees N1, N2 and N3. However, lung cancer cases with less than 10-mm diameter did not have lymph node metastasis. Our study of histologic differentiation showed that all cases of well-differentiated adenocarcinomas (n = 20) were pathological degree N0. The overall sensitivity of preoperative diagnosis increased to 89.1% in cases (n = 74) of tumors with 11-15-mm diameter. The sensitivity of cytodiagnosis for peripheral small-sized primary lung cancers is high, and we can estimate histological differentiation based on the cytological findings. Therefore, cytodiagnosis is an effective and indispensable diagnostic method for determination of the optimal treatment approach, including approaches such as intentionally limited resection.