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Huge Primary Retroperitoneal Mucinous Cystadenoma of Borderline Malignancy Mimickin g an Ovarian Mass: Case Report and Review G. BIFULCO 1, V.D. MANDATO 1, P. GIAMPAOLINO 1, C. NAPPI 1, R. DE CECIO 2, L. INSABATO 2, F. TARSITANO 1 and C. MIGNOGN A2

Departments of 1Gynecology and Obstetrics, and Pathophysiology of Human Reproduction and 2Biomorphological and Functional Sciences, Pathology Section, University of Naples “Federico II”, Naples, Italy

Abstract. Background: Primary retroperitoneal mucinous (1-40). It was found that all of these cases involved adult cystadenoma: is a rare tumor only 48 cases have been reported women except two concerning male patients (18, 35). in international literature. Patients affected by primary Including our case, patients affected by primary retroperitoneal retroperitoneal mucinous cystadenoma/cystadenocarcinoma mucinous cystadenoma/cystadenocarcinoma ranged in age ranged in age from 17 to 86 years (median, 42.3 years) and the from 17 to 86 years (median, 42.3 years) and the size of the size of the cystis ranged from 5 to 35 cm (median, 16.1 cm). cystis ranged from 5 to 35 cm (median, 16.1 cm) (Table I). There is no unanimous opinion on the genesis of these tumors While this neoplasm resembles ovarian mucinous and, due to the ir extreme rarity, its histogenesis, biological neoplasias, this rare neoplasm has been reported in women behavior and the optimal management strategy remain at a with normal ovaries. There is no unanimous opinion speculative level. Case report: We report the case of a huge regarding the genesis of these tumors and, due to the ir borderline primary retroperitoneal mucinous cystadenoma extreme rarity, its histogenesis, biological behaviour and the (24 ×25 cm) in a 35-year-old woman and the strategies adopted optimal management strategy remain at a speculative level. for the diagnosis and surgical management. Conclusion: We report the case of a huge borderline primary Primary mucinous cystic tumor of the retroperitoneum was retroperitoneal mucinous cystadenoma in a 35-year-old woman correctly diagnosed only at the time of surgery. As well as in the and the strategies adopted for the surgical management. majority of cases reported in the literature, preoperative investigations were not able to give information about the tumor Case Report site. In spite of the short follow-up (two years), the patient’s favorable course supports the hypothesis that primary Clinical history. A 35-year-old nulliparous Caucasian woman retroperitoneal mucinous cystadenoma may be treated in the was referred to our Department complaining of pelvic pain. same manner as a primary ovarian tumor of the same grade Her past history included one cesarean section. Physical and comparable stage. examination revealed a huge abdominal swelling and slight abdominal discomfort. Abdominal palpation revealed a large Primary retroperitoneal mucinous cystadenoma (PRMC), soft mass extending from the pelvis over the umbilical line. arising within the retroperitoneal space but outside the major A transabdominal ultrasound and abdominal computer organs within that compartment, is rare. Regarding tomography (CT) confirmed the presence of a large cystic cystadenoma or cystadenocarcinoma in the retroperitoneum, mass (24 ×25 cm) with a single septum extending from the 48 cases have been reported in international literature (Table I) right adnexal region to the upper abdomen between the pancreas and cholecyst. The surrounding organs were compressed and dislocated but not infiltrated (Figure 1). Laboratory findings and tumors markers [CA 125, CA 19-9, Correspondence to: Vincenzo Dario Mandato, Department of CA 15-3, tissue polypeptide- specific antigen (TPS) and Gynecology and Obstetrics, and Pathophysiology of Human carcino embr yonal antigen (CEA)] were within normal range. Reproduction, University of Naples Federico II, Via Pansini 5, An exploratory laparotomy discovered a grossly normal Naples, Italy. Tel/fax: +39 0817462905, e-mail: dariomandato@ virgilio.it uterus and both ovaries. The cystic mass was in the retroperitoneum with no connection to other intra or extr a- Key Words: Primary retroperitoneal mucinous cystadenoma, abdominal organs. The cyst was behind/in the rear of the diagnosis, staging, treatment. cecum and near the last intestinal loop. It had developed up

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Table I. Cases of primary retroperitoneal cystadenoma/cystadenocarcinoma reported in the literature since 1965.

Author Year Gender Age Tumor size Treatment Pathology Evolution (years) (cm)

Douglas et al. (1) 1965 F 18 4.5×4×5 Cx MMCA Spreading and death Williams et al. (2) 1971 F 26 22×16×10 -- - Tykka et al. (3) 1975 F 23 10 TR MMCA Spreading and death Roth et al. (4) 1977 F 48 (550 g) TR MMCA Spreading and death 6 mo. after operation Storch et al. (5) 1980 F 17 17×14×6 TR+LH+BSO+Cx MCA bor Paraovarian recurrence 21 mo. after recurrence Fujii et al. (6) 1986 F 69 23 TR+LH+BSO MMCA NED, 36 mo. Nagata et al. (7) 1987 F 41 12×10×9 TR MCA bor NED Banerjee et al. (8) 1988 F 58 7 TR. Splenectomy. MCA bor Unknown left adrenalectomy F 38 11 TR.+ Resection of Mediastinal metastases descending colon. 4 years after surgery left adrenalectomy Nelson et al. (9) 1988 F 35 20 TR + LH+BSO MMCA NED, 22 mo. Pennell et al. (10) 1989 F 19 6×10 TR MCA NED, 18 mo. Park et al. (11) 1991 F 40 24 TR+LH+BSO MCA F 40 24 TR + LH+BSO MMCA NED, 3 mo. Sondergaard et al. (12) 1991 F 47 13 TR + splenectomy + MCA bor NED, 18 mo. left adenectomy Jorgensen et al. (13) 1991 F 17 8 TR MMCA NED, 9 mo. Gotoh et al. (14) 1992 F 44 12.5 TR + Cx MMCA Spreading and death 4 mo. After operation Rothacker et al. (15) 1993 F 43 12×11×6.5 -- - De Peralta et al. (16) 1994 F 68 8×8 -- - Tenti et al. (17) 1994 F 46 20 TR + LH+BSO MMCA NED, 33 mo. F 45 20 NED, 19 mo. Motoyama et al. (18) 1994 F 42 11 TR NED 1994 M 63 6 MCA bor NED

Bortolozzi et al. (19) 1995 F 67 30×20×10 -- - Carabias et al. (20) 1995 F 43 15 TR + LH+BSO MMCA NED, 24 mo. Lee et al. (21) 1996 F 55 19 TR + LH+BSO MMCA NED, 30 mo. F 45 17 NED, 15 mo. Pearl et al. (22) 1996 F 33 33 TR MCA bor NED, 10 mo. Papadogiannakis et al. (23) 1997 F 33 13x9 TR MCA bor NED, 12 mo. Chen et al. (24) 1998 F 48 15×13×9 LR MCA bor NED, 12 mo. Kehagias et al. (25) 1999 F 21 10x5.5x6 TR MCA - Uematsu et al. (26) 2000 F 86 23 TR + gastrectomy MMCA NED, 72 mo. Balat et al. (27) 2001 F 44 30×20×14 TR MCA - Subramony et al. (28) 2001 F 25 30×25×10 TR MCA NED Suzuki et al. (29) 2001 F 40 12x12x15 TR + appendectomy MMCA NED, 15 mo. Tangjitgamol et al. (30) 2002 F 41 12 TR+LH+BSO+ MMCA NED, 18 mo. appendectomy Isse et al. (31) 2002 F 18 11×8×7 TR MCA NED F 85 21×14×8 TR MCA NED Gutsu et al. (32) 2003 F 41 21×16 TR MCA bor NED, 18 mo. Arribas et al. (33) 2004 F 39 10×9×5 TR MCA - Matsubara et al. (34) 2005 F 36 12×8 TR MCA bor NED, 6 mo. Thamboo et al. (35) 2006 M 64 24 TR MMCA NED, 18 mo. Law et al. (36) 2006 F 35 11 TR MMCA NED, 60 mo. Kassab et al. (37) 2007 F 80 35 TR + LH+BSO MCA NED Bakker et al. (38) 2007 F 45 15 TR MCA bor NED, 12 mo. Cottril et al. (39) 2007 F 22 20×17×15 TR MCA bor - Kashima et al. (40) 2007 F 28 17 TR MMCA NED, 10 mo. Index case 2005 F 35 28 TR + appendectomy+ MCA bor NED, 24 mo. partial omentectomy + multiple biopsies of peritoneum and ovaries

F: female; M: male; Cx: chemotherapy; TR: tumor resection; LR: laparoscopic resection; MCA: mucinous cystadenoma; MCAbor: mucinous cystadenoma borderline malignancy; MMCA: malignant mucinous cystadenocarcinoma; mo: months; NED: no evidence of disease.

2310 Bifulco et al : Primary Retroperitoneal Mucinous Cystadenoma to the head of the pancreas. Other abdominopelvic and retroperitoneal contents were also normal. After peritoneal washing, the cyst was radically resected intact.

Materials and Methods

A frozen evaluation during the surgical excision was performed. The resected lesion was fixed in 10% buffered formalin and multiple extensively sampled sections were then routinely embedded in paraffin and stained with hematoxylin and eosin. The antigens tested by immunohistochemistry were: cytokeratin 7, cytokeratin 20, calretinin, estrogen recept or (ER) and progesterone receptor (PgR). The staging procedure performed was a partial omentectomy, appendicectomy, multiple peritoneal biopsies and biopsies of both ovaries.

Pathological findings. The frozen section revealed a borderline mucinous tumor similar to that generally observed in the ovary.

Histological findings. The resected lesion comprised a 28 cm well- encapsulated retroperitoneal mass. On cut section it was composed of a unilocular cyst with a solid area with papillary projections. The external surface showed no connection to any viscera. Microscopically, the mass was a borderline mucinous tumor similar to that generally observed in the ovary. The cyst was lined by mucino us epithelium with mild to moderate stratification, with mild to moderate cytological atypia; the cystic wall was fairly thin (Figure 2). Although some features of benign mucinous tumor were seen, ovarian tissue was not identified. Immunohistochemically, the lining cells of the cyst were positive for cytokeratin 7 and cytokeratin 20 (Figure 3) and negative for calretinin, while the nuclei of stromal spindle cells was positive for ER and PgR (Figure 4). Final diagnosis was a borderline PRMC. At two years’ follow-up the patient was still free of disease.

Discussion

Primary retroperitoneal mucinous cystadenoma is an extremely rare tumor. The first description of this neoplasm was given by Handfield in 1924 (41) and only 47 cases have been published in the literature since (1-40) (Table I). According to the report by Motoyama et al. (18), these cases referred to female patients with normal ovaries, with the single exception of two Figure 1. (a) CT scan showing: a mass involving the right abdomen (1); male patients. Usually this kind of retroperitoneal tumor is the transverse colon (2), jejunum (3), inferior cava (4) and right kidney asymptomatic. However, the most common symptoms are (5) are compressed and dislocated but not infiltrated. (b) Lower section: abdominal mass, distention, discomfort or pain. mass involving the full abdominal cavity (1); the descending colon (2), jejunum (3) and psoas are dislocated (4). (c) Pelvi c involvement: the Although the widespread use of CT for evaluating rectum (2), terminal ileum (3), bladder (4) and uterus (5) are dislocated. abdominal and retroperitoneal disease has increased the detection rate (42), the relative rarity of similar lesions in the retroperitoneum probably results in an underdiagnosis (43). It is very rare that epithelial cancer occurs in this area, since have postulated that these tumors arise in heterotopic ovarian the surface epithelium is a foreign or ectopic tissue to this tissue ever (14). Notwithstanding, in no case has ovarian tissue territory. Indeed, in the retroperitoneum, many soft tissue ever been found in the tumor. tumors can arise from their native structure (30). The origin of There are several hypotheses regarding the origin and retroperitoneal mucinous tumors is uncertain, histologically histogenesis of PRMC (27). Some authors, such as Williams they resemble ovarian mucinous neoplasms. Several authors et al. (2), assumed that the PRMC may arise from

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Figure 2. ( a) Cystic wall show ing a focal area with glandular Figure 3. Immunohistochemistry stains. (a) Diffuse immunoreaction for proliferation. Glands were lined mainly by a single row of mucin- CK 7. (b) Diffuse immunoreaction for CK 20. secreting columnar epithelium. Small glands infiltrating the stroma with accompanying lymphocytic infiltration (×40). (b) Glands lined by cells showing pleomorphic nuclei and prominent nucleoli (×400). coelomic epithelium, their morphological and biological similarities to ovarian mucinous tumor formation follows supernumerary or heterotopic tissue or from a teratoma and similar steps. proposed two theories in order to give an explanation to this In the present case, the results of the immunohistochemical tumor (18, 22, 39): A teratoma with excessive growth of the staining suggested that the histogenesis of this tumor is more high columnar epithelium placed itself on the other likely from mucinous metaplasia of celomic mesothelium. components becoming a cystadenoma; on the other hand, the Some authors have assumed that an early diagnosis is celomic epithelium, during embryonic growth, underwent important because primary mucinous cystic tumors of the mucinous metaplasia with an invaginated cyst in a retroperitoneum tend potentially to a phased progression into retroperitoneal location (31). Another hypothesis proposed malignancy. However, establishing a preoperative diagnosis of that the retroperitoneal cyst arises from remnants of these tumors is very difficult (18). The appearance of this specialized mesothelial cells of the urogenital ridge (9). neoplasm at CT is very complex. It may be difficult to Another possibility is the case in which the neoplasm may determine the organ in which the disease arises and to origin from enterogenic duplication cyst. differentiate a benign from a malignant type (30). With the Tenti et al. (17) reported an immunohistochemical and exception of a few cases (22, 26, 29), PRMC was not correctly molecular study of two cases of primary retroperitoneal diagnosed from imaging studies, but in the majority of cases the mucinous cystadenocarcinoma. This study concluded that tumor site was in the fact revealed only at the time of surgery. In whatever the histogenesis of PRMC may be, teratoma from the index case, the CT imaging showed that the anatomic ectopic ovarian tissue or from mucinous metaplasia of the compartment from which the mass originated was the ovary.

2312 Bifulco et al : Primary Retroperitoneal Mucinous Cystadenoma

Figure 5. Immunohistochemistry stains: strongly immunoreactive for Ki-67 in areas with glandular proliferation.

regard to the treatment of this neoplasm. Some authors performed only mass resection, other authors added total hysterectomy and bilateral oophorectomy either simultaneously or subsequently. For instance, some recommended total hysterectomy with bilateral salpingo-oophorectomy because recurrence was more frequent when simple tumor excision was performed; the tumor has been said to be influenced by female hormones too (14, 21). However, the prophylactic effects of hysterectomy and bilateral salpingo-oophorectomy are not yet evident and it is not recommended in PRMC (44). The only Figure 4. Immunohistochemistry stains. (a) Immunoreaction for patients that are known to have survived 5 and 6 years, estrogen receptor. (b) Immunoreaction for progesterone receptor. respectively, had not undergone hysterectomy and bilateral salpingo-oophorectomy (26). The role of chemotherapy is also still a subject of Moreover, serum tumor markers such as CA 125, CA 19-9, controversy. Some reports recommended a close follow-up CA 15-3, CEA and alpha-fetoprotein rarely aided in diagnosis instead of adjuvant chemotherapy (9, 36), while others or follow-up. Most of the time, these markers were normal, suggested similar treatment to its histologically similar except in rare cases. Suzuki et al. (29) found an elevated ovarian cancer (21, 29, 36). minimal level of CA 19-9 and tumor-associated In our patient, since the neoplasm was a well-incapsulated galactosyltransferase. Isse et al. (31) reported a case of an borderline tumor, did not infiltrate the adjacent organs, the 18-year-old woman with PRMC in whom only CA 19-9 was ovaries and uterus were grossly normal and without evidence slightly increased. Tenti et al. (17) reported slightly increased of metastatic disease, we performed a radical excision of the levels of CA 125 and alpha-fetoprotein which returned to a mass with staging procedures as for borderline ovarian normal level after treatment. Gotoh et al. (14) reported CA 125 cancer, without hysterectomy and bilateral salpingo- rising at the time of recurrence. Finally, Uematsu et al. (26) oophorectomy. Furthermore, the woman was young (35 found high levels of CEA at the time of diagnosis, probably years old) and she had not completed her childbearing. generated by a synchronous gastric cancer. Therefore, the However, considering the several consequences of cystic tumor markers may be considered just an investigational hysterectomy and bilateral salpingo-oophorectomy, study rather than a useful clinical implement (30). hysterectomy cannot be justified unequivocally for the Traditionally, exploratory laparotomy with complete treatment of PRMC. enucleation of the cyst is the only appropriate approach for In spite of the short follow-up, the patient’s favourable diagnosis and treatment (24). course supports the hypothesis that PRMC may be treated in Various opinions have been expressed on the surgical the same manner as a primary ovarian tumor of the same treatment of PRMC, but the literature is not unequivocal with grade and comparable stage.

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36 Law KS, Chang TM and Tung JN: Fertility-sparing treatment of 42 Stoupis C, Ros PR, Abbitt PL, Burton SS and Gauger J: Bubbles a primary retroperitoneal mucinous cystadenocarcinoma. BJOG in the belly: imaging of cystic mesenteric or omental masses. 113 : 612-614, 2006. Radiographics 14 (4) : 729-737, 1994. 37 Kassab A, El-Bialy G, Clark J, Callen P, Powary M and Jones 43 Adachi S, Doy Y, Tsunoda-Shimizu H and Ozaki A: A small H: Unusual presentation of 22-Kilogram retroperitoneal mucinous cystadenocarcinoma of the liver detected by a fluid- mullerian serous cystadenoma. Gynecol Oncol 104 : 257-259, fluid level on ultrasonography. Surg Today 26 : 439-441, 1996. 2007. 44 Kessler TM, Kessler W, Neuweiler J and Nachbur BH: 38 Bakker RFR, Stoot JHMB, Blok P and Merkus JWS: Primary Treatment of a case of primary retroperitoneal mucinous retroperitoneal mucinous cystadenoma with sarcoma-like nodule. cystadenocarcinoma: is adjuvant hysterectomy and bilateral A case report and review of the literarture. Virchows Arch 451 : salpingo-oophorectomy justified? Am J Obstet Gynecol 187 : 853-857, 2007. 227-232, 2002. 39 Cottrill HM and Roberts WS: Primary retroperitoneal mucinous borderline tumor: A case report. Gynecol Oncol 106 : 626-627, 2007. 40 Kashima K, Yahata T, Fujita K and Tanaka K: Primary retroperitoneal mucinous cys tadenoca rcinoma assoc iated with pregnancy. Int J Gynecol Cancer Nov 19 : 1-5, 2007. Received March 12, 2008 41 Handfield Jones R: Retroperitoneal cysts: their pathology, Revised May 20, 2008 diagnosis, and treatment. Br J Surg 12 : 119-134, 1924. Accepted May 23, 2008

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