S3840 The Cervix as a Rare Site of Colon Cancer Metastasis

Introduction: Despite significant progress in cancer screening and treatment, colon cancer remains a public health concern. Metastatic colon cancer remains a leading cause of cancer-related deaths globally. In existing studies, colorectal cancer most frequently spreads to lungs, liver, and peritoneum, with occasional metastases found in the brain, spleen and bone. Colon cancer metastasizing to the uterine cervix is an exceedingly uncommon occurrence and only a handful of cases have been reported. We present a case of metastatic colon cancer involving the cervix, with recurrent vaginal bleeding being a key presenting feature. Case Description/Methods: A 75-year-old White woman, with a past medical history of metastatic colon cancer status post ileostomy, who presented with a 2-week history of heavy vaginal bleeding and urinary incontinence. Her physical exam upon admission showed a soft, non-tender abdomen, and a genitourinary exam notable for vaginal bleeding and a large clot. Lab studies revealed a hemoglobin of 9.1 g/dl (baseline of 11.7) and an elevated serum creatinine of 2.44 mg/dl. A computed tomography of the abdomen and pelvis demonstrated an enlarging pelvic mass within the rectouterine pouch resulting in severe right greater than left hydroureteronephrosis, and involvement of local deep pelvic structures. A pap smear and biopsies of the cervix and endometrium confirmed adenocarcinoma consistent with the metastasis from the patient's known colorectal cancer. The gynecologic oncology team was consulted who confirmed that the pelvic mass is compatible with her worsening metastatic disease burden. She underwent a right percutaneous nephrostomy placement for decompression and was subsequently discharged home with follow up with her outpatient oncologist and palliative care team. Discussion: Metastasis of a primary colorectal adenocarcinoma to the cervix accounts for less than 2% of all metastases to the gynecologic tract. It can present with a cervical mass and vaginal bleeding as seen in this case or be discovered incidentally during routine gynecologic screening. Metastatic colorectal cancer to the cervix can mimic primary cervical cancer, making diagnosis difficult. In addition to clinical history, immunohistochemical profiling with histologic markers can be helpful for accurate diagnosis and delineation between the 2. Accurate distinction between primary cervical cancer and cervical metastasis from colon cancer is essential as it directly impacts prognosis and therapeutic decisions.