Fallopian tube tumors refer to neoplasms originating in the fallopian tube or its mesosalpinx. These are the least common tumors of the female reproductive system. Compared to malignant tumors of the fallopian tube, benign tumors are even rarer. Advances in pathology and molecular biology have increasingly supported the notion that serous tubal intraepithelial carcinoma (STIC) is the origin of high-grade serous ovarian carcinoma and primary peritoneal carcinoma. Clinical management often groups ovarian cancer, fallopian tube cancer, and primary peritoneal cancer together, applying consistent treatment principles.
Pathology
Benign Fallopian Tube Tumors
Benign tumors of the fallopian tube are rare and typically occur in women of reproductive age. These tumors are usually unilateral and predominantly located in the mesosalpinx, although some protrude into the tubal lumen. They most commonly occur at the fimbrial end, followed by the ampulla. The pathological types are diverse, with literature most frequently reporting adenomatoid tumors. Other epithelial tumor types include serous cystadenofibroma, papilloma, and Müllerian duct cysts. Stromal tumors such as leiomyoma, hemangioma, and lipoma, as well as germ cell-derived mature teratomas, have also been observed.
Malignant Fallopian Tube Tumors
These are most commonly fallopian tube carcinomas originating from the tubal mucosal epithelium. Historically, they were estimated to account for approximately 1 in 50 cases of ovarian cancer. However, advances in pathology and molecular biology have increasingly shown that serous tubal intraepithelial carcinoma (STIC) is a common origin of fallopian tube carcinoma, high-grade serous ovarian carcinoma, and primary peritoneal carcinoma. As a result, the true incidence of fallopian tube carcinoma may have been significantly underestimated. Fallopian tube carcinoma is mostly unilateral, with the ampulla being the most common site, followed by the fimbria. Affected segments appear thickened and "sausage-shaped." Upon cross-section, the lumen often contains papillary or exophytic growths, which are grayish-white or grayish-red in color, with or without accompanying hematosalpinx or hydrosalpinx. Microscopically, the mucosal layer is replaced by tumor cells with significant nuclear atypia, abundant chromatin, and frequent mitotic figures, forming papillary and glandular structures. The most common histological type is high-grade serous carcinoma. Less common types include mucinous carcinoma, endometrioid carcinoma, clear cell carcinoma, transitional cell carcinoma, and undifferentiated carcinoma. Most tumors are poorly differentiated.
Diagnosis
Benign tumors of the fallopian tube typically lack specific clinical symptoms. Most patients are asymptomatic, and due to their rarity, these tumors are challenging to diagnose preoperatively and are often misdiagnosed. The classic "triad" associated with fallopian tube carcinoma includes vaginal discharge, a palpable pelvic mass, and cramping lower abdominal pain, though these features are only present in 5% to 20% of cases. Sonographically, "sausage-shaped" cystic or cyst-solid masses are considered characteristic of fallopian tube carcinoma. However, when fluid from the fallopian tube enters the uterus or peritoneal cavity, the mass may appear solid on ultrasound. The preoperative misdiagnosis rate for fallopian tube carcinoma is high. If a patient exhibits abnormal cervical cytology but has negative HPV testing, colposcopy, cervical biopsy, and endometrial curettage, discrepancies among these results should raise suspicion of primary fallopian tube carcinoma. Additionally, psammoma bodies identified on cervical smears can indicate gynecologic malignancy, warranting further detailed examination. The definitive diagnosis of fallopian tube tumors relies on histopathological evaluation.
Treatment
Benign Fallopian Tube Tumors
Surgical removal is curative for benign fallopian tube tumors. For patients with fertility requirements, tumor location, nature, extent of involvement, and patency of the contralateral fallopian tube should be considered to determine whether to perform tumor resection, partial salpingectomy, or total salpingectomy. Simple salpingectomy does not affect ovarian blood supply or endocrine function. After completing childbearing, concurrent bilateral salpingectomy during gynecological surgeries is recommended to reduce the risk of high-grade serous cancer in the fallopian tube and ovary.
Malignant Fallopian Tube Tumors
The principles of treatment follow those for malignant ovarian tumors.