A case report of appendiceal adenocarcinoma without gastrointestinal evidence mimicking primary ovarian cancer.

Metastatic tumours to the ovary comprise 10-25% of ovarian malignancies and may originate from various primary sites. Here, the case of a 49-year-old female patient who presented with periumbilical nodules and abdominal bloating is reported. She was found to have bilateral ovarian tumours with peritoneal carcinomatosis and ascites. Primary ovarian cancer was suspected while no contributory gastrointestinal lesion was detected by imaging studies and endoscopic examinations. Three cycles of neoadjuvant chemotherapy were administered, followed by interval debulking surgery. Appendiceal cancer was highly suspected based on analysis of a frozen section obtained during surgical debulking. Following the pathology investigation, the patient was finally diagnosed with primary appendiceal adenocarcinoma. She underwent chemotherapy comprising irinotecan and fluorouracil. Due to disease progression despite several chemotherapy regimens, the patient declined further treatment and was lost to follow-up 1 year after the debulking surgery. Metastatic tumours to the ovary may mimic primary ovarian cancers and often present with nonspecific manifestations. Therefore, meticulous exploration of the primary site is warranted if the diagnosis is clinically suspicious.