Surgically transplanted ovary simulating a hepatic metastasis

Abstract

Background

Surgical procedures may alter normal anatomy, confounding the interpretation of cross-sectional imaging studies. This problem is greater if neither a relevant history nor previous comparison studies are available.

Case outline

In a 29-year-old woman submitted to radical hysterectomy for cervical carcinoma, one ovary was surgically reposi-tioned into the right paracolic gutter out of the radiation field. This ovary simulated a hepatic metastasis on subsequent CT examinations. History was obscure, adding to the interpretive challenge.

Discussion

Clues to establishing the correct diagnosis are presented. The availability of an adequate history and previous radiological images are important to prevent diagnostic error.

Introduction

Radiation therapy for cervical carcinoma is a well-accepted adjunctive technique or alternative to operative extirpation of the tumour. Such therapy exposes the ovaries to radiation and may cause cessation of hormonal function ¹. Oophoropexy, or surgical relocation of the ovaries, prior to radiation therapy can be used to preserve ovarian function ². Currently, this procedure can be performed either through a standard laparotomy or by laparoscopic guidance. A variety of possibilities exist for ovarian placement. One option is to transpose the ovaries into the paracolic gutters ³. This manoeuvre allows administration of full pelvic radiation without the ovaries being in the direct radiation beam.

This paper presents a case in which a single ovary was transplanted well cephalad, to lie close to the inferior portion of the right lobe of the liver. This appearance mimicked a hepatic metastasis on subsequent CT examinations, especially as the patient gave no such history and prior records were unavailable.

Case report

A 29-year-old woman underwent radical hysterectomy for squamous cell carcinoma of the cervix. A preoperative CT scan showed indistinctness of the retroperitoneal tissues, predicting sidewall invasion. Histological evaluation of the resected lymph nodes demonstrated lymphatic spread of the carcinoma. These findings were sufficient to warrant both adjunctive chemotherapy and radiation. A single ovary was transplanted adjacent to the inferior portion of the right lobe of the liver to preserve intrinsic hormonal function. Various physicians and institutions were involved with the patient's therapy, so that the full historical information was not provided.

On the 1-year postoperative CT scan (1-cm slices with intravenous contrast), a single, 5-cm complex, septated mass appeared to arise from the inferior portion of the right lobe of the liver (Figure 1a). An exophytic hepatic metastasis was initially considered. During analysis of adjacent axial images, a metallic surgical clip was recognised just inferior to the right hepatic lobe (Figure 1b). This finding prompted further investigation into the surgical history. Record of a previous oophoropexy was uncovered, and this resolved the question of a metastasis. The mass was recognised as the transplanted ovary and had tell-tale ovarian follicles. The remainder of the scan demonstrated no evidence of disease spread.

Figure 1. .

(a) CTscon 1 year after ovarian transplant surgery to protect the patient from radiation therapy demonstrates an apparent complex mass projecting mediaty from the inferior portion of the right lobe of the liver (arrows), (b) CT scan just inferior to the'complex mass’ demonstrates several surgical clips that led to the consideration of an ovarian transplant; this subsequently was confirmed by review of prior medical records that initially were not available.

On the next annual CT scan, different radiologists observed a somewhat similar finding. The current'mass’ was in a similar location, but the size and appearance differed (Figure 2a). Suspicion of a metastasis was raised again, along with the possibility that the previous CT finding may have been misinterpreted. The surgical clip was noted in the same place, and the'mass’ (albeit smaller) was similarly located on the CT scans. Further inspection of the lesion revealed a smooth, septated low-attenuation appearance (Figure 2b). One such area was more prominent than on the previous study, as a functioning luteal cyst would appear on either CT or ultrasound. Because of the history of oophoropexy and presumed different appearances of the transplant on successive examinations in a young woman, it was concluded that the ovary maintained its intrinsic function and showed characteristic hormone-induced cyclical changes.

Figure 2. .

(a) Follow-up scan 9 months later reveals a different appearance to the transplanted ovarian complex. A more homogeneous and cystic appearance is now present due to the change in the hormonal cycle, (b) More caudally, surgical clips are again identified.

Discussion

Approximately half the women affected with cervical cancer are premenopausal and one-third are under the age of 40 years ⁴. Surgical removal of the ovaries or radiation-induced sterility are undesirable in this group of patients. Oophoropexy is a well-established technique to maintain hormonal influence in women who receive pelvic irradiation. The associated risks of oophoropexy include vascular injury, fallopian tube infarction, and cystic changes ⁵. As the technique has evolved, it has become more refined; there are several variations for ovarian position, as well as the choice between open laparotomy or laparoscopic guidance for the procedure. A mature oocyte has even been harvested from an ovary that was transplanted ⁵.

There are few reports on the imaging appearances of transplanted ovaries ⁶,⁷,⁸,⁹. Peritoneal and retroperitoneal sites are most common, and adjacent surgical clips are a helpful diagnostic adjunct. The appearance of the ovary may vary considerably in different phases of the reproductive cycle. Our case emphasises that a proper history, especially of previous operation, is essential to avoid misinterpretation of imaging findings. In our patient, if the transplanted ovary had been reported as a possible metastasis on CT scans, this would have altered the chemotherapy regimen, and subjected her to further investigation such as biopsy or laparotomy, with potential risks. Given the history of squamous cell carcinoma of the cervix, any suspicious hepatic lesion must be considered metastatic until proven otherwise.

The importance of having all prior radiological examinations available for comparison is equally essential. The fact that premenopausal ovaries can manifest different appearances at various times due to physiological changes may be an important clue, as in our patient. Nonetheless, growth of the ovary could be mistaken as tumour growth. Cysts or follicles in the mass provide clues to the diagnosis. A brief discussion with the patient about the timing of her menstrual cycles suggested that scans were performed during different phases of her hormonal cycle. Finally, the metal clips may be valuable landmarks of the previous operation.