Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive sarcoma usually arising in the abdomen or pelvis of young males under 30 years of age. We present a case of a 32-year-old male with a palpable axillary mass and multiple bilateral lung nodules. Excisional biopsy of the axillary mass showed sheets and nests of small round cells with numerous mitoses, areas of necrosis, and desmoplastic stroma. Initial immunohistochemical stains performed at an outside institution demonstrated immunoreactivity for epithelial markers and focal reactivity for breast markers. The tumor was initially diagnosed as poorly differentiated carcinoma, with consideration of a possible primary breast cancer. Additional workup demonstrated strong, diffuse positivity for desmin in tumor cells, leading to the final diagnosis of DSRCT. Subsequent molecular testing confirmed DSRCT with EWSR1 gene rearrangement. This case illustrates the importance of recognizing the morphologic features of DSRCT in the setting of uncommon location or patient age.