7072^ Background: Lymph node (LN) status is the most important prognostic determinant after resection of lung cancer. 18% of a SEER cohort and 12% of a Memphis cohort had no LNs examined (pNx). Patients with pNx have inferior survival to T-category matched pN0 patients with at least 1 LN examined. The optimal number of LN needed to safely declare a patient pN0 may be >10. Less than 20% of resections in SEER achieve this. We hypothesized that a significant number of intrapulmonary LNs are left unexamined and some may harbor metastatic disease. We report the size characteristics of materials examined in a re-dissection protocol to test this hypothesis. Methods: Prospective study of lung resection specimens re-dissected after signout of the final pathology report. Remnant lung material was dissected with thin cuts and all LN-like material was retrieved for microscopic examination, irrespective of size or location. The size of non-LN tissue, LN without metastasis and LN with metastases were compared using the Wilcoxon-Mann-Whitney test. Results: 112 specimens were examined and 1,094 LN-like materials were retrieved. 749 (69%) proved to be LN tissue. 71 (10%) LNs retrieved had metastasis. Non-LN tissue was significantly smaller than LN tissue (p<0.0001). LNs with metastasis were significantly larger than those without metastasis (p <0.0001). 60% of materials >2cm were LNs with metastasis. 7% of materials <1cm were LN with metastasis. 52% of LNs with metastasis, and 55% of LNs without metastasis measured from 0.5 to 1.5cm (Table). Majority of LNs >2cm had metastatic disease, but 40% did not; a notable proportion of LNs with metastasis were small. Nearly equal percentages of LNs with and without metastasis were found in the range of 0.5-1.5cm. Conclusions: Statistical differences in size between lymph nodes with and without metastasis is clinically meaningless due to broad overlap. LN size alone is not an adequate predictor of LN metastasis. [Table: see text]