Background. Small cell carcinoma in the uterine corpus rather than the endometrium has not been reported yet which resembles a uterine leiomyosarcoma on an imaging study. Furthermore, gynecologic malignancies manifested as a visual dysfunction render the early suspicion and accurate diagnosis a difficult proposition. Case. A 57-year-old Korean woman was referred to the Department of Obstetrics and Gynecology due to incidentally detected uterine mass. She had been suffering from a visual loss for several weeks. This uterine mass mimicking a leiomyosarcoma on pelvis MRI was identified to be a small cell carcinoma via a transvaginal gun biopsy and consequent immunostaining. The patient was then scheduled to undergo a regimen of chemotherapy with etoposide and carboplatin. Conclusion. Small cell carcinoma may arise from the uterine corpus rather than the endometrium and may also be accompanied by visual symptoms. Background, Small cell carcinoma in the uterine corpus rather than the endometrium has not been reported yet which resembles a uterine leiomyosarcoma on an imaging study. Furthermore, gynecologic malignancies manifested as a visual dysfunction render the early suspicion and accurate diagnosis a difficult proposition. Case. A 57-year-old Korean woman was referred to the Department of Obstetrics and Gynecology due to incidentally detected uterine mass. She had been suffering from a visual loss for several weeks. This uterine mass mimicking a leiomyosarcoma on pelvis MRI was identified to be a Small cell carcinoma via a transvaginal gun biopsy and consequent immunostaining. The patient was then scheduled to undergo a regimen of chemotherapy with etoposide and carboplatin. Conclusion. Small cell carcinoma may arise from the uterine corpus rather than the endometrium and may also be accompanied by visual symptoms.