Sonographic Features of Ovarian Remnants Arthur C. Fleischer, MD, David Tait, MD, Jack Mayo, MD, Lonnie Burnett, MD, Jean Simpson, MD Ovarian remnants occur after a portion of ovarian tissue is left behind unintentionally after oophorectomy. The ovarian remnant may be functional and cystic, producing pelvic pain and, in some patients, extrinsic compression of the distal ureter. Ovarian remnants frequently are associated with adhesions from previous pelvic surgery for endometriosis or pelvic inflammatory disease. Ovarian remnants also may be included within pelvic peritoneal inclusion cysts. In this retrospective study, the sonographic features of ovarian remnants in 10 patients with surgical proof or clinical follow-up data are described. Most ovarian remnants were simple cysts (seven of 10), three had multiple septations, and six had a rim of presumably ovarian tissue with arterial and venous flow. Three patients with ovarian remnant masses that were aspirated had symptomatic relief without recurrence. In one patient, guided aspiration was unsuccessful, probably owing to the presence of organized hemorrhage within the mass. Extrinsic compression of the distal ureter was observed in one patient, who was treated with gonadotropin releasing hormone agonist (Lupron). The sonographic findings of a completely cystic or multiseptated pelvic mass with a rim of vascularized solid tissue in a postoophorectomy patient, although such cases are rare, suggest the diagnosis of an ovarian remnant. If the diagnosis can be established with a high degree of certainty, sonographically guided aspiration may be attempted in an effort to provide symptomatic relief. Otherwise, sonography is useful in serial assessment of these masses in patients receiving medical treatment. KEY WORDS: Ovary, remnant; Transvaginal sonography; Remnant, ovarian. Ovarian remnant syndrome is a known but relatively uncommon complication of difficult bilateral oophorectomy. 1,2 The remnant of ovarian tissue left behind after surgical removal can become functional and cystic, producing pelvic pain or extrinsic compression of the distal ureter, or both. The presence of a cystic mass in the pelvis in a woman with a history of bilateral Received February 19, 1998, from the Departments of Radiology and Radiological Sciences (A.C.F., J.M.), Obstetrics and Gynecology (D.T., L.B.), and Pathology (J.S.), Vanderbilt University Medical Center, Nashville, Tennessee. Revised manuscript accepted for publication June 14, 1998. Address correspondence and reprint requests to Arthur C. Fleischer, MD, Department of Radiology and Radiological Sciences, RR-1213 MCN, Vanderbilt University Medical Center, 21st Avenue South and Garland, Nashville, TN 37232 2675. salpingo-oophorectomy is suggestive of an ovarian remnant. Ovarian remnants may become incorporated within a peritoneal cyst. Ovarian remnants commonly are described as a sequela of pelvic surgery for endometriosis or pelvic inflammatory disease. Ovarian remnant syndrome should be considered distinct from residual ovary syndrome, in which pelvic symptoms originate from the ovaries preserved at the time of hysterectomy. The theoretical basis for ovarian remnant syndrome was revealed by the work of Shemwell and Weed, 3 who showed that ovarian tissue implanted onto the peritoneum of cats could survive after separation from its blood supply. This development of parasitic blood supply allows the ovarian tissue to remain responsive to the hypothalmic-pituitary-ovarian axis. 1998 by the American Institute of Ultrasound in Medicine J Ultrasound Med 17:551 555, 1998 0278-4297/98/$3.50
552 OVARIAN REMNANTS J Ultrasound Med 17:551 555, 1998 The present study describes the sonographic features of ovarian remnants as well as the therapeutic outcome in a small number of patients whose mass was aspirated using sonographic guidance. MATERIALS AND METHODS The case material from a group of 10 women with surgically proved ovarian remnant syndrome (seven surgically proved and three clinically presumed on the basis of analysis of aspirated fluid) that had been collected over a 7 year period was analyzed retrospectively. The women s ages, surgical histories, and sonographic features are listed in Table 1. Both transabdominal sonography and transvaginal sonography were performed in all cases. Color Doppler interrogation was performed in six patients. Standard scanning protocols were used. RESULTS This study consisted of 10 women ranging in age from 35 to 70 years (average, 53 years). All had undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy. Their clinical data are listed in Table 1. Three women had a history of endometriosis, three had bowel disorders, one had had a mucinous cystadenoma removed, one had von Willebrand disease, and one had non-hodgkin lymphoma. The length of time after surgery until the patient came for evaluation ranged from 5 months to 50 years (average, 16 years). All patients complained of pelvic pain. The masses ranged from 2 to 10 cm in average dimension (Figs. 1 to 6). Most lesions (seven of 10) had smooth walls, three had septa, and six had a rim of presumably ovarian tissue. Of the four masses with a focal area of solid tissue, three had arterial and venous flow within the solid area on transvaginal color Doppler sonography. In one patient with a dense area of fibrosis found later at surgery, no flow was detected. Table 1: Clinical and Sonographic Findings Patient Figure History Sonographic Features Other Findings 1* 1 35 yr old, 7 yr post TAH 3 cm multiloculated hemorrhagic mass Serum FSH = 2 miu/ml; and 2 yr post BSO, with pain LH = 1.6 pg/ml 2* 2 53 yr old, 3 yr post TAH 3 5 cm fusiform cystic mass Aspirated fluid; E 2 = and BSO, with 15 pg/ml; no recurrence mucinous cystadenoma 3* 3 60 yr old, 30 yr post TAH 3 4 cm multiloculated cystic mass Aspirated; no recurrence and BSO, with von Willebrand disease 4 4 34 yr old, 6 months post TAH 10 cm multiseptated, partially solid mass; Aspiration attempted but and BSO arterial flow in wall unsuccessful 5 5 45 yr old, 12 yr post TAH and 8 10 cm smooth-walled cyst with Aspirated; no recurrence BSO, history of Crohn disease arterial flow in wall 6* 6 74 yr old, 33 yr post TAH and 10 12 cm cystic mass with arterial BSO, with diffuse pelvo- and venous flow within ovarian remnant abdominal pain 7* 41 yr old, 20 yr post TAH and 2 cm smooth-walled cyst with arterial flow BSO, with history of endometriosis, in wall five laparotomies for pelvic cysts 8* 35 yr old, 9 yr post TAH and BSO 2 3 cm irregularly shaped cyst 9* 37 yr old, 5 yr post TAH/BSO; 3 4 cm solid mass with venous flow history of endometriosis 10 70 yr old, 27 yr post TAH and 5 7 cm septated mass with BSO, with non-hodgkin arterial and venous flow in lymphoma wall *Surgical proof. TAH, Total abdominal hysterectomy; BSO, bilateral salpingo-oophorectomy; FSH, follicle stimulating hormone; LH, luteinizing hormone; E 2, estradiol.
J Ultrasound Med 17:551 555, 1998 FLEISCHER ET AL 553 Figure 1 Transabdominal color Doppler sonogram from a 35 year old woman with acute pelvic pain who had had total abdominal hysterectomy and bilateral salpingo-oophorectomy. A partially cystic structure containing fine strands is seen within a mass that has a well vascularized wall. This was found to represent a hemorrhagic corpus luteum within an ovarian remnant. Figure 2 Transvaginal sonography in a 53 year old woman with acute pelvic pain who had undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy 3 years ago. A fusiform cystic mass that was nonvascular is present in the left adnexa. At surgery, the distal portion of the left tube was found to be obstructed by adhesions crossing the ovarian fossa, accounting for its fusiform shape. A small remnant of ovarian tissue was found near the fimbriated end of the tube. Of the seven patients who underwent reoperation, all had histologically proven ovarian tissue. Three patients had a presumptive diagnosis of ovarian remnant on the basis of aspiration of fluid and clinical follow-up results. Of the four patients whose masses were aspirated with sonographic guidance, three reported immediate symptomatic relief. The cytologic findings on the aspirated fluid in all patients indicated a benign lesion. The aspirated fluid from one patient s mass had an estradiol value of 15 pg/ml. Another patient s aspirated fluid showed a follicle-stimulating hormone level of 2 miu/ml and luteinizing hormone level of 16 pg/ml, indicating ovarian origin. In one patient with a probable endometrioma with organized hemorrhage, aspiration was unsuccessful. In three patients, the mass had not recurred on follow-up scans obtained 5 to 15 months after aspiration. In one patient, the mass persisted and was removed surgically. Figure 3 Transvaginal sonography in a 60 year old woman who had undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy 30 years ago and also had von Willebrand disease. A multiloculated cystic mass is seen within the ovarian remnant. Eight milliliters of clear fluid was aspirated with alleviation of symptoms.
554 OVARIAN REMNANTS J Ultrasound Med 17:551 555, 1998 A B Figure 4 Transvaginal sonogram from a 34 year old woman with complex pelvic mass with septa and solid tissue, who had a history of endometriosis and who had undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy 3 years ago. A, Arterial and venous flow was present in the solid area. Sonographically guided aspiration was unsuccessful even though the needle tip was properly placed within the mass. B, Follow-up sonogram 6 months later shows evolution of hemorrhagic area within the ovarian remnant. DISCUSSION The sonographic appearance of ovarian remnants varies from small to relatively large cystic or multiseptated masses that contain a rim of vascularized ovarian tissue. Ovarian remnants can be differentiated from peritoneal cysts by documenting the presence of ovarian tissue in the wall of a mass. Because of the limited numbers in our series we were not able to estimate the prevalence of vascular versus hypovascular ovarian tissue or the specificity of this finding. Although color Doppler sonography can suggest the existence of functional ovarian tissue by the presence of flow, it cannot always allow distinction between areas of fibrosis and scarring that may appear as a rim of vascularized solid tissue. The surrounding wall of a peritoneal inclusion cyst that involves an ovarian remnant is derived from the mesothelium of the peritoneum, which is usually avascular. 4 Sonographically guided aspiration may provide a means for symptomatic relief through nonsurgical decompression of the mass. If the mass contains functioning ovarian tissue, masses may enlarge or regress, depending on the presence of follicular or luteal cysts. On the basis of results from our limited series, it seems appropriate to attempt to provide symptomatic relief in some patients by sonographically guided aspiration. On sonography, peritoneal inclusion cysts can be distinguished from ovarian remnants by careful evaluation of the rim of such masses. 4 Peritoneal cysts may contain a normal ovary inside an anechoic cyst, whereas only a thin rim of ovarian tissue can be seen in an ovarian remnant. The existence of arterial and venous flow within the solid tissue usually indicates that vascularized ovarian tissue is present. The majority of patients in this series had pelvic pain many years after initial surgery (total abdominal hysterectomy and bilateral salpingo-oophorectomy). Some patients had had multiple operations whereas others had intercurrent diseases, such as endometriosis, which may increase the likelihood of adhesions surrounding the ovary. Figure 5 Transvaginal color Doppler sonogram from a 45 year old woman with a cystic mass who had had a total abdominal hysterectomy and bilateral salpingo-oophorectomy 12 years ago. Arterial flow is evident within the presumed ovarian remnant.
J Ultrasound Med 17:551 555, 1998 FLEISCHER ET AL 555 Sonography provides important data concerning the size and accessibility of the mass to sonographically guided aspiration. In our limited experience, sonographically guided aspiration provided symptomatic relief and may offer the patient an alternative to repeat surgery in some cases. Medical pretreatment with gonadotropin releasing hormone agonists (Lupron) also may be used to shrink ovarian remnants, particularly those causing extrinsic compression of the ureter. 5 Lupron therapy is both therapeutic and diagnostic, as resolution of the cyst after administratration of this agent confirms the presence of ovarian tissue. Documentation of flow with an ovarian remnant by color Doppler sonography may be helpful in predicting which masses are vascularized and therefore most amenable to medical management. Sonography has an important role in the management of cases of suspected ovarian remnant syndrome. Even though the treatment of each patient needs to be tailored to her specific clinical concerns, women under the age of 45 years with suspected ovarian remnant may be considered for an initial trial of medical therapy followed by sonographically guided aspiration should the medical treatment fail or symptoms persist. Owing to the increased prevalence of ovarian cancer in women older than 45 to 50 years, surgical treatment may be indicated. Sonographically guided aspiration may be useful in women who are poor surgical candidates. REFERENCES 1. Riva JM, Mikuta JJ: Ovarian remnant syndrome. Postgrad Obstet Gynecol 4:1, 1984 2. Lafferty HW, Angioli R, Ruldolph J, et al: Ovarian remnant syndrome: Experience at Jackson Memorial Hospital, University of Miami, 1985 through 1993. Am J Obstet Gynecol 174:641, 1996 3. Shemwell RE, Weed JC: Ovarian remnant syndrome. Obstet Gynecol 36:299, 1970 4. Kim JS, Lee HJ, Woo SK, et al: Peritoneal inclusion cysts and their relationship to the ovaries: Evaluation with sonography. Radiology 204:481, 1997 5. Koch MO, Coussens D, Burnett L: The ovarian remnant syndrome and ureteral obstruction: Medical management. J Urol 152:158, 1994 Figure 6 Transvaginal color Doppler sonogram from a 74 year old woman with a cystic left adnexal mass who had undergone a total abdominal hysterectomy and bilateral salpingooophorectomy. Arterial and venous flow is present within the ovarian remnant.