Malignant lymphomas with a prominent spindle-cell or sarcomatoid pattern are unusual tumors typically of T- or null-cell phenotypes. We encountered a case of a 32-year-old woman who presented with a 3-week history of excessive menstrual bleeding, left lower-quadrant pain, and weight loss. A mass involving the uterine cervix and right parametrium was detected on pelvic examination and imaging studies. A diagnosis of diffuse large B-cell lymphoma with a spindle-cell pattern was made with immunohistochemical and gene rearrangement studies on endocervical curettage and parametrial core biopsy specimens. After chemotherapy and radiation therapy, the patient was in clinical and radiological remission 10 months after diagnosis. To our knowledge, this is the first sarcomatoid B-cell lymphoma presenting in the uterine cervix. Awareness of the spindle-cell pattern of diffuse large B-cell lymphoma and its possible presentation in extranodal sites such as the uterine cervix should prevent potential misdiagnosis.