LAUSR

Introduction Colorectal cancer is the second leading cause of cancer-related death in the United States when both genders are combined, but in Puerto Rico is the leading cause of cancer-related death. Puerto Rican men and women ages 40 to 59 years have a greater risk of incidence and mortality than their United States Hispanic counterparts. Most commonly, colorectal cancer spreads to the regional lymph nodes (52%), liver (78%), lung (20%), and peritoneum (29%). However, solitary metastases without evidence of a primary lesion are extremely rare, and the mediastinum as initial site of presentation has only been described a few times in the medical literature.We present a case of 45year-old Hispanic male, with a diagnosis of stage IV (T0 N0 M1 G3) colorectal adenocarcinoma, which was referred to the clinic because of an anterior mediastinal mass and no other primary lesion. The patient provided written consent to publish this data.