Atypical adnexal mass misdiagnosed as an ovarian tumor revealing a bilateral tubal cancer. Case report

Abstract

Introduction and importance

Primary epithelial cancers of the tube are a rare entity. They represent less than 2 % of gynecological tumors and are dominated by adenocarcinoma. Due to its proximity to the uterus and the ovary, the diagnosis of tubal cancer is very difficult to confirm, frequently misdiagnosed as a benign ovarian or tubal pathology. This may explain the underestimation of this cancer.

Presentation of case

We report a case of a 47 years old patient diagnosed with a pelvic mass, the patient had an hysterectomy with omentectomy revealing a bilateral tubal adenocarcinoma after the histopathological examination.

Clinical discussion

Tubal adenocarcinoma is a more common pathology in postmenopausal women. The treatment is similar to that for ovarian cancer. Symptoms and the serum CA-125 level may be helpful indicators but are neither specific nor always found. Therefore, careful intraoperative assessment of the adnexa is necessary.

Conclusion

Despite the refinement of diagnostic tools available to clinicians, it is still difficult to diagnose the tumor beforehand. Nonetheless, the diagnosis of tubal cancer must be suspected in the context of a differential diagnosis of an adnexal mass. Abdomino-pelvic ultrasound is the key examination in the diagnostic process and the discovery of a suspicious adnexal mass leads to the performance of a pelvic MRI and, if necessary, to surgical exploration. The therapeutic principles follow those of ovarian cancer. Efforts should be focused on the creation of regional and international registries of tubal cancer cases in order to achieve greater statistical power in future studies.

Highlights

• •Despite the refinement of diagnostic tools available to clinicians, it is still difficult to diagnose the tumor beforehand.
• •The diagnosis of tubal cancer must be suspected in the context of a differential diagnosis of an adnexal mass.
• •Ultrasound is the key examination in the diagnostic process and the discovery of a suspicious adnexal mass leads to the performance of a pelvic MRI and, if necessary, to surgical exploration.
• •Therefore, careful intraoperative assessment of the adnexa is necessary.

1. Introduction

Primary fallopian tube carcinoma (PFTC) is a rare tumor, accounting for about 0.3 to 1.8 % of all gynecological malignant tumors [1]. Because of the proximity of the uterus and ovary, the diagnosis of primary cancer of the fallopian tube is very difficult to confirm and is based on very rigid criteria: either the presence of a macroscopic lesion in the fallopian tube and the absence of a tumor of the ovary and uterus, or if applicable, a tumor of a different histological type from those of the uterus and/or ovary. The true incidence of cancers of the tube, especially serous carcinomas, is probably underestimated because they could be confused in the advanced stages with serous carcinoma ovarian cancers, of which they are histologically close, both on ultrasound and per-operatively [2]. The objective of this article is to report a case of a 47 years old woman with an atypical adnexal mass revealing a bilateral papillary cancer, and to analyze the clinical and paraclinical characteristics, that can help in the diagnosis.

The therapeutic principles have been modelled on those of ovarian cancer, but analysis of the results is difficult because of the low frequency and heterogeneity of the series. We ensure that the work has been reported in line with the SCARE 2020 criteria [3].

2. Presentation of case

This is a 47 year old female patient, having had one child by vaginal birth (12 years ago). The patient has no particular pathological history, and has been menopausal for 2 years. She consulted for chronic pelvic pain and weight loss (5 kg in 6 months) with progressive abdominal distension without any palpable mass, nor any other associated signs. She was referred by her family physician. The clinical examination revealed a patient in good general condition, apyretic, with normal blood pressure and no abdominal mass. Examination under speculum showed a normal cervix, vaginal examination showed a normal uterus with right side adnexal fullness. The rest of the physical examinations were unremarkable.

At admission, her vital signs were normal. Tumor markers showed normal CA 19-9, CA 125 and CA 15-3. Her hemogram and metabolic panel were within normal. Pelvic ultrasound showed a right ovarian solid mass (9 × 8 cm). Doppler revealed vascular invasion. MRI showed a right adnexal solid mass (8,3 × 7,2 cm), with well-defined walls, incomplete folds, displaying low signal intensity on T1 and high signal intensity on T2, and central necrosis of the mass, and presence of ascites. The MRI findings were suggestive of right ovarian epithelial neoplasm, and did not show significant abdominal lymphadenopathy nor peritoneal deposits. CT abdomen was not done as MRI is superior to detect ovarian cancer in cases of adnexal mass and it was deemed sufficient at this stage. The patient was discussed at the gynecology multidisciplinary team (MDT) meeting and the decision was to proceed to surgery.

3. Surgical technique and findings

The patient was admitted for diagnostic laparotomy with total abdominal hysterectomy, bilateral salpingo-oophorectomy, possible omentectomy and lymph node dissection. After a midline abdominal incision and entering the peritoneum, she had 600 ml of ascites, with a right large solid mass of the right fallopian tube as well as slightly enlarged left fallopian tube, with normal right and left ovaries and uterus. There were also small and large bowel adhesions, the appendix, the liver, spleen, kidneys were normal on palpation, with no peritoneal nodules.

We performed a hysterectomy and bilateral salpingo-oophorectomy and infra colic omentectomy. This was undertaken by an experienced surgeon. Intra-operative frozen section was not done due to its reported controversy with the frequent diagnostic discordance between the frozen section and final pathology. Post-operative period was uneventful and the patient recovered smoothly, pain management accomplished via morphine patient-controlled analgesia (PCA) which was stopped on day 3, she started full diet on day 3, and was discharged on the forth post-operative day with no complains. Her histopathology report showed a well-differentiated papillary serous adenocarcinoma of tubal origin in the right fallopian tube as well as in the left fallopian tube, the uterus and both ovaries were free of tumors, with presence of malignant cells in the ascites. The patient was once again discussed at the MDT meeting and the decision was to proceed with 6 courses of postoperative chemotherapy using taxol and cisplatin (TP). The patient was followed up for 2 years with no recurrence.

4. Discussion

PFTC is an uncommon gynecologic tumor generally recognized as a disease of menopausal women [4]. Because of the low frequency of PFTC, only about 4 % are diagnosed preoperatively [5], and up to 50 % are missed intraoperatively. This is why unlike ovarian cancer, PFTC is not usually suspected in a patient with a complex pelvic mass, and furthermore in early stages when the patient is symptom-free [6]. Therefore, careful intraoperative assessment of the adnexa is necessary. Moreover, symptoms and the serum CA-125 level may be helpful indicators but are neither specific nor always found. The Latzko's triad of typical tubal carinoma's symptoms is the combination of pelvic pain, a pelvic mass, and serosanguineous vaginal discharge. However, none of these symptoms are specific, and this triad was reported in only 15 % of PFTC cases [5]. In addition, numerous studies have found a correlation of CA-125 level with FIGO stage, but not with a PFTC prognosis [7]. The etiology of PFTC remains unclear; some studies have shown that PFTC and ovarian carcinoma share several biological and clinical features [8]^, [9]. Chronic tubal inflammation, infertility, endometriosis, nulliparity, smoking, and genetic predisposition seem to increase the risk of PFTC [10]. Some studies have reported that pelvic serous carcinoma could follow a defined precursor of the distal fallopian tube that has been present for some time [11]^, [12]. Imaging studies such as ultrasound, computed tomography, or magnetic resonance imaging may aid in diagnosing PFTC. Although the imaging findings of tubal carcinoma are nonspecific, and mimic other pelvic diseases such as tubo-ovarian abscess or ovarian tumor, several findings may provide a diagnostic clue preoperatively. A sausage-shaped mass or a multilobular mass with a cog-and-wheel appearance on ultrasound [13], or low-impedance vascular flow within the solid components on ultrasound with color Doppler might lead to a suspicion of tubal malignancy [14]. Magnetic resonance imaging is considered a better method than computed tomography or ultrasound for detecting tumor infiltration of extratubal organs [15]. The gold-standard treatment for managing PFTC is similar to that for ovarian carcinomadcytoreductive surgery with the removal of as much of the tumor as possible [15]. However, which chemotherapy regimen is optimum to address PFTC remains unclear. More recently, paclitaxel-based chemotherapy has been used for PFTC based on the propensity to use the same therapy for epithelial ovarian cancer. With the introduction of cisplatin-containing chemotherapy regimens, an objective response rate of about 80 % can be achieved in patients with advanced disease [16]^, [17]. PFTC has many biological and clinical characteristics in common with epithelial ovarian cancer, but PFTC seems to recur more often in retroperitoneal nodes and distant sites [5]. Important prognostic parameters for survival are stage, patient age [7]^, [9]^, [10], and, among patients with advanced-stage disease, residual tumor after initial surgery [9]. Other reported additional determinants of good prognosis including serous type which has a better prognosis than endometroid, the presence of ostial closure which, and a negative peritoneal cytology [18].

5. Conclusion

Despite the refinement of diagnostic tools available to clinicians, it is still difficult to diagnose the tumor beforehand. Nonetheless, the diagnosis of tubal cancer must be suspected in the context of a differential diagnosis of an adnexal mass. Abdomino-pelvic ultrasound is the key examination in the diagnostic process and the discovery of a suspicious adnexal mass leads to the performance of a pelvic MRI and, if necessary, to surgical exploration. The therapeutic principles follow those of ovarian cancer. But the analysis of the results is difficult because of the low frequency and heterogeneity of the series. The use of color Doppler and, more recently, 3D ultrasound and 3D energy Doppler has considerably refined the ultrasound diagnostic criteria for tubal cancers. Efforts should be focused on the creation of regional and international registries of tubal cancer cases in order to achieve greater statistical power in future studies.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

The authors institute provided ethical approval for this case study.

Sources of funding

We declare there was no sources of funding.

Author contribution

Chadia Khalloufi: Conceptualization, Data curation, Writing Original draft preparation, Reviewing and Editing.

Imane Joudar: Writing, Reviewing and Editing.

Kanas Aya: Writing, Reviewing and Editing.

Moustapha Benhessou: Supervision.

Mohammed Ennachit: Supervision.

Mohammed El Kerroumi: Validation.

Guarantor

Khalloufi Chadia.

Research registration number

Not applicable.

Declaration of competing interest

The authors declare that they have no conflict of interest.