S1676 A Case of Rectal Primary Krukenberg Tumor

Abstract

INTRODUCTION: Krukenberg Tumors (KTs) are secondary ovarian tumors defined as mucinous signet-ring cell carcinomas. Nearly 30% of ovarian tumors are metastatic in origin, with KTs accounting for 1–2% of all ovarian tumors. Worldwide, stomach is the primary site in most KT cases (70%), followed by colorectal and breast. However, in Europe and the USA, colorectal and breast cancers are the most common primary tumors metastasizing to the ovaries. KTs occur in 3–14% of women with colorectal cancer (CRC), with 20% arising from the rectum. The prognosis for KTs is poor, although CRC primary KTs appear to benefit from more aggressive treatment with cytoreductive surgery and post-adjuvant chemotherapy. We present a case of rectal primary KT to improve awareness of CRC KTs in the western population, as well the implications of histological type on management. CASE DESCRIPTION/METHODS: Our patient is a 48 year old African American female who underwent surgical resection of a 6.6cm complex right ovarian mass seen on MRI after having reported one year of abdominal pain, nausea, and progressive constipation. Ascites was noted prior to surgery. Final surgical pathology specimens demonstrated mucinous carcinoma with signet ring features. Immunohistochemical (IHC) evaluation was CK20+/CDX2+ and CK7-, suggestive of colorectal primary. Laboratory values were notable for CEA 1.0ng/mL, CA-125 44 U/mL, and the absence of iron deficiency anemia. An upper endoscopy was performed, ruling out gastric malignancy. A colonoscopy revealed a non-traversable malignant appearing stricture 15 cm from the anal verge with biopsies demonstrating poorly differentiated adenocarcinoma with signet cell features. Our patient was lost to follow up for several months as she explored alternative natural therapies before ultimately transitioning to hospice care with palliative FOLFOXIRI. DISCUSSION: CRCs are a relatively common primary source for KTs in the western population. While the median survival of patients with KTs is 14 months, there is a small but promising body of evidence that select patients with CRC primary KTs may have a survival benefit with optimal cytoreductive surgery and post-adjuvant chemotherapy. IHC markers may help identify the primary tumor, as the pattern of CK20+/CDX2+ and CK7- is classic for a colorectal primary. Our case serves to improve awareness of CRC primary KTs, and the unique treatment survival benefits for these patients.Figure 1.: MRI image of a 6.6cm complex right ovarian mass.Figure 2.: Invasive signet ring cells forming cords and nests within ovarian stroma (x40 hematoxylin and eosin stain).Figure 3.: Non-traversable rectal stricture 15cm from the anal verge.