Primary retroperitoneal mucinous cystadenocarcinoma (PRMCa): a systematic review of the literature and meta-analysis

Management of retroperitoneal high-grade serous carcinoma of unknown origin: A case report

BACKGROUND

Retroperitoneal high-grade serous carcinoma (HGSC) of unknown origin is a sporadic tumor that can originate from ovarian cancer. Herein, we report the case of a woman with retroperitoneal HGSC of unknown origin and describe how she was diagnosed and treated.

CASE SUMMARY

A 71-year-old female presented with the tumor marker CA125 elevated to 1041.9 U/mL upon a regular health examination. Computed tomography revealed retroperitoneal lymph node enlargement. Subsequently, positron emission tomography scanning revealed lesions with increased F-18 fluorodeoxyglucose uptake at the nodes. As a result, she underwent laparoscopic lymph node resection, and pathology revealed metastatic adenocarcinoma with CK7(+), PAX8(+), WT1(+), PR(-), and p53 mutational loss of expression, indicating that the origin may be from the adnexa. The patient was admitted to our ward and underwent laparoscopic staging; however, the pathological results were negative. Under the suspicion of retroperitoneal HGSC of unknown origin, chemotherapy and targeted therapy were initiated. Tumor marker levels decreased after treatment.

CONCLUSION

We present a case of HGSC of unknown origin managed using retroperitoneal lymphadenectomy, staging surgery, chemotherapy, and targeted therapy.

Primary Retroperitoneal Mucinous Cystadenocarcinoma during Long-term Administration of Infliximab for the Treatment of Crohn's Disease

We herein report a rare case of primary retroperitoneal mucinous cystadenocarcinoma (PRMC) in a 60-year-old man. The patient, who had been treated with infliximab for Crohn's disease of the colon for 13 years, was referred to our hospital for lower back pain. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging revealed multiple cystic lesions in the right retroperitoneum, the calcification of the cyst, and bone lesions. Bone and CT-assisted biopsies of the retroperitoneal lesions revealed poorly differentiated adenocarcinoma. The patient was diagnosed with PRMC with bone metastases using immunohistochemical staining and positron emission tomography/CT.

Primary Retroperitoneal Carcinomas: New Insights into Pathogenesis and Clinical Management in Comparison with Ovarian Carcinomas and Carcinoma of Unknown Primary

Primary retroperitoneal carcinomas are very rare tumors. Their pathogenesis remains unknown but may be associated with that of ovarian carcinomas, considering the similarity in morphology and gender preference. Although metaplasia of coelomic epithelium is the most widely accepted theory, the pathogenesis of retroperitoneal carcinomas may differ by histologic subtype, like ovarian carcinomas. Mucinous carcinoma, which develops in both women and men, may originate in both primordial germ cells and Walthard cell nests that may be derived from the fallopian tube. Serous carcinomas may be associated with endosalpingiosis, the presence of fallopian tube-like epithelium outside the fallopian tube, and a remnant Müllerian tract. Endometrioid and clear cell carcinomas appear to be associated with extraovarian endometriosis. Additionally, both carcinomas in the retroperitoneal lymph nodes may be metastatic diseases from endometrial and/or renal cell cancer that regress spontaneously (carcinoma of unknown primary). Retroperitoneal carcinomas are difficult to diagnose, as they have no characteristic symptoms and signs. Surgery is the cornerstone of treatment, but the necessity of chemotherapy may depend on histological subtype. Further studies are necessary, in particular studies on endosalpingiosis, as endosalpingiosis is a poorly understood condition, although it is associated with the development of both serous and mucinous carcinomas.

Spectrum of MRI Features of Mucin-producing Neoplasms in the Abdomen and Pelvis

Mucin-producing neoplasms in the abdomen and pelvis are a distinct entity, separate from simple fluid-containing neoplasms and loculated fluid collections. Mucin is a thick gelatinous substance and-owing to its high water content-has imaging features that can be mistaken for those of simple fluid-containing neoplasms with multiple imaging modalities. However, mucin-producing neoplasms arise from specific organs in the abdomen and pelvis, with unique imaging appearances, knowledge of which is important to guide accurate diagnosis and management. With its large field of view and high soft-tissue resolution, MRI has advantages over other imaging modalities in characterizing these neoplasms. The authors focus on the spectrum of MRI features of such mucin-producing neoplasms and illustrate how-despite a varied organ origin-some of these neoplasms share similar MRI and histopathologic features, thereby helping narrow the differential diagnosis. One common finding in these tumors is that the presence of internal complexity and solid enhancing components increases as the degree of malignant transformation increases. Lack of internal complexity generally indicates benignity. These tumors have a varied range of prognosis; for example, a low-grade appendiceal mucinous neoplasm is indicative of a good prognosis, while a mucinous tumor of the rectum is known to manifest at an early age with aggressive behavior and poorer prognosis compared with its nonmucinous counterpart. Online supplemental material is available for this article. ^©RSNA, 2022.

Primary Retroperitoneal Müllerian Adenocarcinoma: Report of Two Cases Treated With Radical Surgery

BACKGROUND

Primary retroperitoneal Müllerian adenocarcinoma (PRMA) is a very rare type of primary retroperitoneal tumour. CASE 1: A 45-year-old woman presented with left lower extremity swelling and pain. Imaging revealed that the tumour had invaded the left common iliac vein and artery, internal and external iliac arteries, sciatic and obturator nerves, and pelvic wall. CASE 2: A 37-year-old was admitted with pelvic pain. Imaging showed the tumor at the left iliac bifurcation infiltrating the internal iliac artery and left sciatic, obturator, and femoral nerves. Both of these patients were treated with radical surgery that achieved no visible tumour at the end of the operation.

CONCLUSION

There is no guideline for the diagnosis and management of this entity due to its rarity. These cases should be managed at highly specialized centres with expertise in radical surgery.

Laparoscopic Resection and Pre-Operative Imaging of Primary Retroperitoneal Mucinous Neoplasms: A Retrospective Case Series

Purpose

The purpose of this paper is to present the clinicopathological features of primary retroperitoneal mucinous neoplasms (PRMNs), to evaluate the diagnostic role of pre-operative radiological examinations, and to determine the feasibility of total resection using the laparoscopic approach.

Methods

We retrospectively analysed the clinicopathological and radiological features of 10 PRMN cases who underwent surgical resection from January 2000 to December 2019.

Results

Ten PRMN cases were evaluated in this study, including 1 malignant case, 4 borderline cases, and 5 benign cases. The most common primary complaints were pain (60%) and palpable mass (60%). Of the 8 cases with pre-operative CT results, 75% of the borderline or malignant cysts and none of the benign cysts were large in size (size>11.6 cm). Half of the non-benign masses and none of the benign ones were lobulated. Thick wall (≥3 mm) and irregular wall were found in 25% and 50% of the non-benign cases, respectively. Wall enhancement was detected in 75% of the non-benign cases and 25% of the benign cases. Enhanced mural nodules were identified in 50% of the non-benign patients. Septa were found in 25% of the non-benign cases. Complete dissection of the tumour without rupture or post-operative complications was achieved laparoscopically in 90% of the cases. All patients were alive with no recurrence at the last follow-up at an average of 28.1±26.6 months.

Conclusion

Larger size and lobulation of the cyst, presence and contrast enhancement of thick and irregular cyst walls, mural nodules, and internal septa may be imaging features suggestive of malignancy. Complete resection of PRMN through the laparoscopic approach is feasible in experienced institutions.

Primary retroperitoneal mucinous cystadenocarcinoma with transition from the mesothelium

INTRODUCTION

Mucinous cystic neoplasms are uncommon among the tumors that develop in the retroperitoneum. We report a case of primary retroperitoneal mucinous cystadenocarcinoma with pathological considerations.

CASE PRESENTATION

A 47-year-old woman complaining of abdominal discomfort presented at our hospital. Abdominal computed tomography and magnetic resonance imaging showed a large cystic tumor with small solid nodules located in the right retroperitoneum. The tumor was completely removed and the microscopic findings were consistent with primary retroperitoneal mucinous cystadenocarcinoma. Two years after the surgery, the patient is alive without recurrence of the tumor.

CONCLUSION

The microscopic findings suggested that the primary retroperitoneal mucinous cystadenocarcinoma developed from the metaplasia of the remnant coelomic epithelium. A complete tumor resection that includes the adjacent peritoneum is important to prevent local recurrence.

First Report of Retroperitoneal Mucinous Cystadenoma in a Patient with Hirsutism

Primary retroperitoneal mucinous cystadenomas (PRMC) are rare benign neoplasms with only 55 documented cases in the English literature so far. A 19-year-old female exhibited hirsutism and was found to have a cystic mass measuring 5.8 cm × 3.9 cm × 5.8 cm in the left retroperitoneum. During subsequent work up, a high pre-operative value of dehydroepiandrosterone sulfate (DHEA-S) was noted. The patient was referred to surgical oncology and underwent an uneventful laparoscopic cystectomy. Pathology classified the cyst as PRMC. Post-operatively, the patient's DHEA-S levels normalized, though there was no appreciable decrease in the patient's hirsutism in the short-term follow-up. The origin of PRMC is uncertain. Due to their unknown biological potential, surgical resection is usually recommended. To the best of our knowledge, this is the first report documenting a PRMC and elevated levels of androgens in conjunction with hirsutism.

Primary retroperitoneal serous adenocarcinoma: A case report of rare malignancy with literature review

The primary retroperitoneal serous adenocarcinoma (PRSAC) is a rare malignant tumor of the retroperitoneum. It shares the same pathological and biological behavior with ovarian serous carcinoma. Most of the cases develop as peritoneal adenocarcinoma and rarely occur in the retroperitoneum. It is reported as serous surface papillary carcinoma of the peritoneum and extraovarian peritoneal serous papillary carcinoma. We present a case of PRSAC in a 60-year-old woman. Only 11 cases of PRSAC have been reported from 1983 to 2019. Histopathological features with immunohistochemical expressions are important to diagnose PRSAC. The outcome and survival mainly depend on the possibility of surgical resection. Molecular genetics of PRSAC should also be studied in relation with its ovarian counterpart.

Primary Retroperitoneal Mucinous Tumours Diagnosed in Pregnancy: A Case Report and Literature Review

We present the case of a pregnant patient who was found to have a primary retroperitoneal mucinous tumour (PMRT). An abdominal mass measuring 11.5 × 9.8 × 8.8cm, initially thought to be of ovarian origin, was found incidentally on ultrasound in a 36-year-old patient at 20 weeks’ gestation. Tumour markers were normal. She underwent an elective Caesarean section at 34 weeks, but the uterus, fallopian tubes and ovaries were normal. The mass was found to be retroperitoneal. A clinical decision was made to avoid further surgical exploration at the time. Following further surgical planning, the patient underwent open resection of the retroperitoneal mass, 6 weeks after her Caesarean section. Histology confirmed a moderately differentiated adenocarcinoma suggestive of a primary retroperitoneal mucinous adenocarcinoma. A literature review following this identified five case reports of PMRT in pregnancy in the last decade. In all cases, the patients underwent tumour resection without adverse pregnancy outcomes. While our patient had an uncomplicated pregnancy, she developed a 2cm lesion suggestive of disease recurrence 15 months post-operatively. A plan was made for surgical resection. PMRT are rare, but can occur in pregnant patients and patients of childbearing age. Tumour resection should be carried out, but where there is no concrete evidence of tumour invasion, the uterus and ovaries should be spared to avoid infertility and menopause. We would recommend early tumour resection, given its potentially aggressive nature.

A rare case of a primary retroperitoneal mucinous cystic tumour with borderline malignancy and literature review

Primary retroperitoneal mucinous cystic neoplasms (PRMCN) with borderline malignancy are exceptionally rare tumours with lack of pathognomonic clinical and imaging-specific features. Here, we report a case of PRMCN with borderline malignancy in a 62-year-old woman who presented with abdominal pain. Imaging studies revealed a well-defined cystic mass on the right flank in close relation with the cecum and caecal appendix, without other findings suggestive of malignancy. A possible diagnosis of an ovarian epithelial tumour was ruled out intraoperatively. After surgical excision, microscopic examination allowed the final diagnosis. As there is no evidence of disease during follow-up, complete tumour resection without cystic rupture appears to be the best therapeutic option. Thus, although rare, this tumour should be considered when imaging findings suggest an ovarian mucinous neoplasm in women with normal ovaries. An international registry for rare tumours and longer follow-ups may contribute for more consistent approach for managing these patients.

A case report and a literature review of primary retroperitoneal mucinous cystadenoma: the importance of imaging in diagnosis and management

Primary retroperitoneal mucinous cystadenoma (PRMC) is an extremely rare tumor: its histogenesis and its biological behavior remain speculative. Since most retroperitoneal tumors are malignant, a preoperative diagnosis of benignity is essential and it can be reached through imaging examinations, allowing a conservative management approach. We describe the case of a 52-year-old woman with abdominal pain and a palpable mass. Computed tomography of the abdomen revealed a retroperitoneal cystic mass, which was resected successfully through laparoscopy and diagnosed as PRMC. Although there are no pathognomonic, clinical or radiological findings for PRMC, it should be included in the list of differential diagnoses and its imaging criteria of benignity should always be sought, with the aim to exclude malignant tumors.

Management of Primary Retroperitoneal Mucinous Tumors: A Retrospective Meta-Analysis

OBJECTIVE

Primary retroperitoneal mucinous tumors (PRMTs) are rare epithelial neoplasms arising in the retroperitoneal space whose pathogenesis is poorly understood. To date, only single-case reports and small case series on diagnosis and management of these tumors exist. The aim of this first-time meta-analysis was to provide more reliable data to inform the management of PRMTs.

METHODS

Database searches were conducted to identify case reports and case series between the years of 1975 and 2015. Two cases of patients treated at our institution were also included. Diagnostic, radiographic, surgical, and follow-up data were gathered. Regression modeling was used to identify factors aiding preoperative diagnosis and affecting treatment. Survival analysis including Cox regression modeling was performed to provide insights into treatment effects on the prognosis of female patients with PRMTs.

RESULTS

One hundred forty-four cases of PRMTs were included in this analysis. Eighty-nine percent occurred in women. Most of the PRMTs were found to be malignant (53%). No preoperative factors predicting tumor dignity were identified by multiple regression analysis. Five-year disease specific survival of patients with benign and borderline tumors was excellent, reaching 100%, whereas it was only 68% for patients with malignant disease. Adjuvant surgical treatments including hysterectomy, salpingoophorectomy, and lymph node dissection were not associated with a statistically significant survival advantage. However, there was a nonsignificant association of hysterectomy with improved survival (hazard ratio, 0.42; 95% confidence interval, 0.09-2.07; P = 0.285). Adjuvant chemotherapy was associated with reduced survival (hazard ratio 3.791; 95% confidence interval, 1.509-9.526; P = 0.0046).

CONCLUSIONS

A reliable diagnosis of a PRMT can only be made by pathological examination of the tumor. Surgical excision is thus necessary to facilitate diagnosis while it also remains the mainstay of treatment. There is no conclusive evidence supporting the role of adjuvant surgical procedures or chemotherapy.

The long-term survival in primary retroperitoneal mucinous cystadenocarcinoma: a case report

Background

Primary retroperitoneal mucinous cystadenocarcinoma (PRMC) is extremely rare, and its biological behavior, pathogenesis, optimum treatments, and prognosis remain to be elucidated. We herein report a case of PRMC with an 80-month follow-up.

Case presentation

A 29-year-old woman was diagnosed with unknown retroperitoneal tumor with benign right ovarian cyst and uterine fibroids, and she underwent laparotomy. The tumor was completely resected with a subsequent histopathological diagnosis of primary retroperitoneal mucinous cystadenocarcinoma (PRMC). Eighty months after surgery, she remains recurrence-free.

Conclusion

PRMC is an extremely rare tumor. Only around 60 cases have so far been published in the literature. The preoperative diagnosis of PRMC is difficult, and a definitive diagnosis can usually only be made based on the findings of histopathological examinations after surgery. Presently, only radical resection is useful for both diagnostic and therapeutic purposes. The optimal long-term management after surgery is still not well established. Further studies on PRMC are therefore needed to elucidate the etiology and establish effective treatments.