['Angiogenesis in individuals with various solid tumors has provided useful information on tumor progression and prognosis, and many examples of mast cell (MC) accumulation coupled with angiogenesis can be found in the literature.', 'Utilizing monoclonal antibodies for tryptase that are specific markers for MC and for the endothelial surface marker CD34, the authors quantified MC infiltration in 180 patients with pulmonary adenocarcinoma who underwent curative tumor resection, to investigate the relation between mast cell density (MCD) and microvessel density (MVD), clinicopathologic factors, and prognosis.', 'A significant association was found between MCD and MVD (P < 0.0001). The MC count was significantly related to tumor progression, involving N classification and stage (P = 0.0002 for N classification and P = 0. 0015 for stage). A significant difference in the rate of patient survival was detected between patients whose tumors had an MCD defined as high and those whose tumors had an MCD defined as low (P < 0.0001). Multivariate analysis also showed that MCD was significantly related to survival (P = 0.0378).'] Is mast cell density associated with angiogenesis and poor prognosis in pulmonary adenocarcinoma?