Synchronous or Metastatic Gastric and Ovarian Malignancies: A Diagnostic Challenge

Abstract

Primary ovarian carcinoma is the prevailing form of cancer in the female reproductive system, leading to a substantial number of cancer-related fatalities globally. One of the major obstacles encountered in diagnosing this condition is distinguishing between primary gastrointestinal tumors and tumors that have metastasized from the ovaries, since they may exhibit similar histological characteristics. This case report underscores the difficulties involved in determining whether multiple tumors originate primarily or are a result of metastasis. We report a case of a 65-year-old female who presented with abdominal pain and was found to have a large multiloculated cystic mass in the right ovary and a poorly detected left ovary on ultrasound and CT scan. Her serum CA125 level was elevated. She underwent exploratory laparotomy and frozen section analysis of the right ovarian and gastric tumors. The histopathological diagnosis was mucinous cystadenocarcinoma of the ovary and well differentiated adenocarcinoma of the stomach. She also underwent hysterectomy with left salpingo-oophorectomy, which revealed mucinous cystadenocarcinoma of the left ovary. Immunohistochemical staining for specific markers, including CK7, CK20, CDX2, and PAX8, was conducted to identify the origin of the adenocarcinoma. The results revealed that both ovarian and gastric tumors showed a positive expression for CK7, while CK20 was negative in the gastric tumor but positive in the ovarian tumor. Furthermore, both CDX2 and PAX8 were negative in both the gastric and ovarian tumors. These findings provide valuable insights into the differential diagnosis and help to distinguish the possible sources of the adenocarcinoma. This case emphasizes the significance of histopathological examination and immunohistochemistry profiling in accurately diagnosing and determining the primary tumor site. Recognizing the primary tumor and its immunohistochemistry profile aids in guiding treatment strategies and predicting patient prognosis, leading to improved management and outcomes. Keywords Ovarian carcinoma, Gastric carcinoma, Immunohistochemistry