Primary Fallopian tube carcinoma (FTC) is a rare gynecological malignancy that most commonly presents in postmenopausal women, usually in the sixth decade of life1–4. Nulliparous women appear to be at higher risk for developing FTC5. Typical presenting symptoms include abdominal pelvic pain or pressure and vaginal bleeding3. Bleeding is frequently associated with watery vaginal discharge. ‘Hydrops tubae profluens’ is a syndrome characterized by colicky lower abdominal pain relieved by a profuse, serous, watery, yellow intermittent discharge from the vagina. It is thought to be caused by filling and emptying of a partially blocked Fallopian tube. However, it is absent in most cases6. Because of its rarity, the preoperative diagnosis of FTC is difficult and rarely made before surgery. Since the prognosis is mostly related to the stage of the disease, it is very important to be familiar with the imaging characteristics of FTC in order to establish early diagnosis and thus improve prognosis.
A 43-year-old, premenopausal, nulliparous patient with last menstrual period 3 weeks prior presented with a history of left-sided lower abdominal pain and copious, watery vaginal discharge for 9 months. She had regular menses, lasting 2–5 days. She had no history of infertility and reported no medications. She had commenced sexual activity 2 years prior to presentation and had one lifetime partner. On physical examination a pool of fluid was noted in the posterior vaginal fornix. White blood cells but no organisms were noted on a wet mount and cytological evaluation was negative for malignancy. Pelvic examination revealed bilateral adnexal pain, a left adnexal mass and some nodularity in the cul-de-sac. The uterus was normal and the ovaries could not be palpated. Transabdominal and transvaginal sonography were performed. Moderate discomfort was elicited during the transvaginal portion of the examination. The uterus was anteverted. A small amount of fluid was noted within the endometrial cavity. A thin-walled, ovoid-shaped structure measuring 8 × 5 × 5 cm was seen on the left adnexa (Figure 1). This structure contained an incomplete septation and a solid nodule with multiple areas of blood flow (Figure 2). Spectral Doppler from the ovaries revealed a lowest resistance index (RI) of 0.6 and a pulsatility index (PI) of 1.1. The right adnexa contained a hydrosalpinx. The ovaries were visualized separately and contained a few scattered follicles. No free fluid was seen in the cul-de-sac. In view of its unique quality, these findings were reported as suggestive of left FTC. The CA 125 level was 27.1 U/mL (within normal limits). The remainder of the preparatory work-up was unremarkable.
An exploratory laparotomy was performed and bilateral hydrosalpinges were found. Frozen section of the left tube revealed a dilated tube containing a mostly necrotic tumor consistent with adenocarcinoma (Figure 3). A staging procedure was performed including a total abdominal hysterectomy and bilateral salpingo-oophorectomy, omentectomy, lymph node resection and diaphragmatic biopsy. The final diagnosis was consistent with a moderately differentiated, serous, papillary adenocarcinoma of the left Fallopian tube, Stage IA and right chronic salpingitis.
Primary FTC is one of the rarest gynecological malignancies, accounting for 0.18% to 1.6% of all malignant neoplasms of the female reproductive tract1. Because of its rarity, preoperative diagnosis of primary FTC is rarely made and it is usually misdiagnosed as ovarian carcinoma. Slanetz et al.3 evaluated 20 patients with a discharge diagnosis of primary FTC. Of these, 14 were thought to represent ovarian or endometrial carcinoma on the basis of clinical presentation, physical examination and preoperative imaging, and only 3/20 cases were suspected to be primary FTC before surgery. Nevertheless, preoperative diagnosis of primary FTC has been reported previously by several authors2, 3, 7–15.
Sonographic features of FTC are non-specific and include the presence of a fluid-filled adnexal structure with a significant solid component9, a sausage-shaped mass10, a cystic mass with papillary projections within11, and a multilocular mass with cogwheel appearance2. In the present case, there was a high suspicion of primary FTC due to the presence of an ovoid-shaped structure containing an incomplete septation and a highly vascular solid nodule. The presence of an incomplete septation has been previously reported as the best marker for tubal inflammatory disease by Timor-Tritsch et al.16. This finding made possible the characterization of the adnexal mass as being of tubal origin. The solid nodule visualized within the tubal structure contained multiple blood vessels, which also contributed to the suspicion of malignancy. In contrast to a previous report by Kurjak et al.8, spectral Doppler values were not consistent with high diastolic flow in the present case. In Kurjak's report, eight patients with FTC were evaluated by transvaginal color and pulsed Doppler sonography. In all of these patients, adnexal masses with low vascular impedance (RI in the range 0.29–0.40) were found. Low vascular impedance values were explained by the concept that tumor vessels of malignant lesions have reduced muscular wall, an incomplete endothelium, and a higher density of arteriovenous shunts when compared to vessels of benign lesions. These factors are known to cause higher diastolic flow, which is responsible for the decrease in the PI and RI. As previously mentioned, in the present case the RI and PI were not suspicious for malignancy. This may be secondary to the fact that this disease was diagnosed at an early stage (Stage IA), where neovascularization may not have been as widespread. The gray-scale findings, especially the presence of an adnexal mass with a solid component seen separated from the ovary, together with the multiple blood vessels within the solid portion of the mass, in addition to the patient's clinical features (abdominal pain and copious, watery, vaginal discharge) were sufficient to raise a high suspicion of FTC. It is important to emphasize that the presence of an adnexal mass with a solid component is one of the most important features in the ultrasonographic evaluation of malignant disease. Several ultrasonographic scoring systems have addressed this issue17–19. Using transvaginal sonography, Lerner et al.19 evaluated 312 patients with a total of 300 adnexal masses. In this study, the most discriminatory variable for the diagnosis of adnexal malignancy was the presence of papillary formations and solid areas within the mass.
To our knowledge, this is the first report in the English literature where an adnexal mass with an incomplete septation has been associated with the preoperative sonographic diagnosis of FTC. Although rare, FTC must be considered in the differential diagnosis of adnexal masses, particularly in the presence of incomplete septations and a highly vascular, solid component. Table 1 summarizes the sonographic features that have been associated with a diagnosis of FTC.
Table 1. Sonographic findings associated with Fallopian tube carcinoma
Fluid-filled adnexal structure with a significant solid component
Sausage shaped mass
Cystic mass with papillary projections
Multilocular mass with cogwheel appearance
Cystic mass with incomplete septations
Adnexal mass with low vascular impedance
Only by having a high degree of suspicion will we be able to increase the preoperative diagnostic rate of this pathology.