Collision carcinoma is a rare malignancy that generally occurs in cervical, esophageal, pulmonary, and squamous cell cancers. Few studies have been reported involving endometrial adenocarcinoma and fallopian tube carcinoma. We reported the case of a 58-year-old woman who presented because of irregular vaginal bleeding for more than 1 month. Cervical biopsy suggested moderately differentiated cervical adenocarcinoma, and the patient underwent radical hysterectomy under general anesthesia. However, postoperative pathology and immunohistochemical results indicated a collision tumor comprising endometrial adenocarcinoma (grade I) and primary serous fallopian tube carcinoma. According to the treatment principle of multiple primary tumors, a regimen of paclitaxel combined with carboplatin was administered. The patient also underwent local pelvic radiotherapy to treat lymph node metastasis. One month later, the patient developed brain metastases and died.
Keywords: Collision carcinoma; diagnosis; endometrial adenocarcinoma; immunohistochemistry; postoperative pathology; primary serous fallopian tube carcinoma.