A Rapidly Growing Small-Intestinal Metastasis from Lung Cancer

Small-intestinal metastasis from lung cancer, although relatively rare, often causes intestinal obstruction, gastrointestinal perforation, and gastrointestinal bleeding, making it an oncological emergency. Many patients have undergone emergency surgery for treatment of rapid progression of an intestinal metastatic lesion; however, information on changes in such metastases is lacking. We analyzed data from 4 patients with small-intestinal metastases from lung cancer who were treated during a 10-year period (January 2011 to December 2020) and for whom data on change in tumor diameter were available. The average rate of growth in tumor volume was 1.48-fold (range, 1.31- to 1.78-fold) during a median observation period of 22 (4-39) days, a rapid increase. Histopathological analysis showed that, in patients with a high degree of primary tumor atypia, rapid tumor growth may be caused by intratumoral hemorrhage, which was the reason for the rapid increase in tumor volume.