Early stage rectal cancer metastatic to the ovary.

A 60-year-old Caucasian woman without a significant medical history was diagnosed with a rectal mass 12 cm from the anal verge on screening examination in March 2003. A low anterior resection was performed revealing a moderately differentiated adenocarcinoma extending to the submucosal layer. None of the lymph nodes removed had evidence of metastatic disease, thus the tumor was classified as a Stage I (Duke's A) cancer of the rectum (T1, N0, M0). The pre-op CEA level was 1.7 ng/ml. In July 2003, the patient reported occasional lower abdominal pain. Repeat CEA level was 2.0 ng/ml and a CT scan of the abdomen and pelvis revealed only uterine fibroids. Surveillance colonoscopy in September 2003 was within normal limits, however the CEA level increased to 8.7 ng/ml one month later. A second CT scan of the abdomen and pelvis again showed only uterine fibroids. In November 2003, the CEA level was 15.2 ng/ml. Since the preceding work-up of the rising CEA was unrevealing, a whole body PET scan was obtained. The PET images demonstrated one suspicious hypermetabolic lesion in the pelvis just to the right of the midline. A combination PET/CT scan showed the hypermetabolic lesion in the right ovary. Upon exploratory laparotomy, a firm 3 cm mass was palpated within the right ovary. A bilateral salpingo-oophorectomy was performed revealing adenocarcinoma consistent with metastatic rectal cancer within the right ovary. There was no evidence of metastatic disease in the left ovary, the fallopian tubes, or the multiple lymph nodes removed. Metastatic disease to the ovaries is uncommon. Among patients with ovarian metastases from colorectal cancer, most have either bilateral ovarian involvement or distant metastatic disease. To our knowledge, this is the first reported case of an isolated, unilateral ovarian metastasis from colorectal cancer that was initially detected by a PET scan.

Asghar Naqvi, MD, Celyne L. Bueno, MD, and Derrick W. Spell, MD. Louisiana State University Health Sciences Center, Division of Hematology/Oncology, Department of Internal Medicine, Earl K. Long Medical Center, Baton Rouge, LA.