Unravelling Peritoneal Carcinomatosis Using Cross-Sectional Imaging Modalities

Peritoneal carcinomatosis (PC) refers to malignant epithelial cells that spread to the peritoneum, principally from abdominal malignancies. Until recently, PC prognosis has been considered ill-fated, with palliative therapies serving as the only treatment option. New locoregional treatments are changing the outcome of PC, and imaging modalities have a critical role in early diagnosis and disease staging, determining treatment decision making strategies. The aim of this review is to provide a practical approach for detecting and characterizing peritoneal deposits in cross-sectional imaging modalities, taking into account their appearances, including the secondary complications, the anatomical characteristics of the peritoneal cavity, together with the differential diagnosis with other benign and malignant peritoneal conditions. Among the cross-sectional imaging modalities, computed tomography (CT) is widely available and fast; however, magnetic resonance (MR) performs better in terms of sensitivity (92% vs. 68%), due to its higher contrast resolution. The appearance of peritoneal deposits on CT and MR mainly depends on the primary tumour histology; in case of unknown primary tumour (3-5% of cases), their behaviour at imaging may provide insights into the tumour origin. The timepoint of tumour evolution, previous or ongoing treatments, and the peritoneal spaces in which they occur also play an important role in determining the appearance of peritoneal deposits. Thus, knowledge of peritoneal anatomy and fluid circulation is essential in the detection and characterisation of peritoneal deposits. Several benign and malignant conditions show similar imaging features that overlap those of PC, making differential diagnosis challenging. Knowledge of peritoneal anatomy and primary tumour histology is crucial, but one must also consider clinical history, laboratory findings, and previous imaging examinations to achieve a correct diagnosis. In conclusion, to correctly diagnose PC in cross-sectional imaging modalities, knowledge of peritoneal anatomy and peritoneal fluid flow characteristics are mandatory. Peritoneal deposit features reflect the primary tumour characteristics, and this specificity may be helpful in its identification when it is unknown. Moreover, several benign and malignant peritoneal conditions may mimic PC, which need to be considered even in oncologic patients.

Primary and secondary tumors of the peritoneum: key imaging features and differential diagnosis with surgical and pathological correlation

Peritoneal malignancies represent a diagnostic challenge for abdominal radiologists, oncologists, surgeons and pathologists in multidisciplinary teams, who must address their differential diagnosis, staging and treatment. In this article, we explain the pathophysiology of these processes and lay out the role of different imaging techniques in their evaluation. Then, we review the clinical and epidemiological aspects, the main radiological features and the therapeutic approaches for each primary and secondary peritoneal neoplasm, with surgical and pathological correlation. We further describe other rare peritoneal tumors of uncertain origin and a variety of entities that may mimic peritoneal malignancy. Finally, we summarize the key imaging findings of each peritoneal neoplasm to facilitate an accurate differential diagnosis that may impact patient management.Clinical relevance statementImaging plays an essential role in the evaluation of peritoneal malignancies, assessing their extension, detecting unfavorable sites of involvement and facilitating an accurate differential diagnosis, helping to choose the best therapeutic approach.

Peritoneal disease: key imaging findings that help in the differential diagnosis

The peritoneum is a unique serosal membrane, which can be the site of primary tumors and, more commonly, secondary pathologic processes. Peritoneal carcinomatosis is the most common malignant condition to affect the peritoneal cavity, and the radiologist plays an important role in making the diagnosis and assessing the extent of disease, especially in sites that may hinder surgery. In this review, we address the role of the radiologist in the setting of peritoneal pathology, focusing on peritoneal carcinomatosis as this is the predominant malignant process, followed by revising typical imaging findings that can guide the differential diagnosis.We review the most frequent primary and secondary peritoneal tumor and tumor-like lesions, proposing a systemic approach based on clinical history and morphological appearance, namely distinguishing predominantly cystic from solid lesions, both solitary and multiple.

Quantitative analysis of the MRI features in the differentiation of benign, borderline, and malignant epithelial ovarian tumors

Objective

This study aims to investigate the value of the quantitative indicators of MRI in the differential diagnoses of benign, borderline, and malignant epithelial ovarian tumors (EOTs).

Materials and methods

The study population comprised 477 women with 513 masses who underwent MRI and operation, including benign EOTs (BeEOTs), borderline EOTs (BEOTs), and malignant EOTs (MEOTs). The clinical information and MRI findings of the three groups were compared. Then, multivariate logistic regression analysis was performed to find the independent diagnostic factors. The receiver operating characteristic (ROC) curves were also used to evaluate the diagnostic performance of the quantitative indicators of MRI and clinical information in differentiating BeEOTs from BEOTs or differentiating BEOTs from MEOTs.

Results

The MEOTs likely involved postmenopausal women and showed higher CA-125, HE4 levels, ROMA indices, peritoneal carcinomatosis and bilateral involvement than BeEOTs and BEOTs. Compared with BEOTs, BeEOTs and MEOTs appeared to be more frequently oligocystic (P < 0.001). BeEOTs were more likely to show mild enhancement (P < 0.001) and less ascites (P = 0.003) than BEOTs and MEOTs. In the quantitative indicators of MRI, BeEOTs usually showed thin-walled cysts and no solid component. BEOTs displayed irregular thickened wall and less solid portion. MEOTs were more frequently characterized as solid or predominantly solid mass (P < 0.001) than BeEOTs and BEOTs. The multivariate logistic regression analysis showed that volume of the solid portion (P = 0.006), maximum diameter of the solid portion (P = 0.038), enhancement degrees (P < 0.001), and peritoneal carcinomatosis (P = 0.011) were significant indicators for the differential diagnosis of the three groups. The area under the curves (AUCs) of above indicators and combination of four image features except peritoneal carcinomatosis for the differential diagnosis of BeEOTs and BEOTs, BEOTs and MEOTs ranged from 0.74 to 0.85, 0.58 to 0.79, respectively.

Conclusion

In this study, the characteristics of MRI can provide objective quantitative indicators for the accurate imaging diagnosis of three categories of EOTs and are helpful for clinical decision-making. Among these MRI characteristics, the volume, diameter, and enhancement degrees of the solid portion showed good diagnostic performance.

Primary peritoneal serous carcinoma: a primer for radiologists

Primary peritoneal serous carcinoma (PPSC) is a rare primary peritoneal tumor characterized by a unique range of clinical features and imaging findings. Though it shares many clinical, histologic, and imaging features with serous ovarian carcinoma, it remains a distinct clinical entity. Although less common than its primary ovarian counterpart, PPSC is characterized by a prognosis that is often equally poor with presentations common in late stages of disease. Key imaging modalities used in the evaluation of PPSC include ultrasound, CT, MRI, and PET/CT. For radiologists, an understanding of the pertinent imaging findings, pathologic correlations, and clinical features of PPSC is essential for arriving at the correct diagnosis and guiding the subsequent appropriate management of this complex malignancy.

Magnetic resonance imaging findings of extrauterine high-grade serous carcinoma based on new pathologic criteria for primary site assignment

BACKGROUND

There has been no study that has reported magnetic resonance imaging (MRI) findings of extrauterine high-grade serous carcinomas (HGSCs) that have been histologically determined by the new criteria.

PURPOSE

To assess MRI findings of extrauterine HGSCs based on new pathologic criteria.

MATERIAL AND METHODS

Fifty patients with histopathologically proven extrauterine HGSCs, who underwent pretreatment gadolinium-enhanced MRI, were included in this study. After surgery, the primary sites were histopathologically determined based on new criteria for primary site assignment in extrauterine HGSCs as follows: fallopian tube (n = 34); ovary (n = 9); primary peritoneal HGSC (n = 1); and tubo-ovarian (n = 6). We retrospectively reviewed MR images and compared the MR findings between tubal and ovarian primaries.

RESULTS

MRI patterns with tubal primaries were classified as ovarian cancer (62%), peritoneal cancer (35%), and fallopian tube cancer (3%). MRI patterns with ovarian primaries were classified as ovarian cancer (78%) and peritoneal cancer (22%). The frequency of the involvement of the fallopian tube, ovary, peritoneum, uterus, and lymph node was not significantly different between the two pathologies. There was no significant difference in the abnormal amount of ascites, hemorrhagic ascites, or characteristics of the ovarian lesions between the two pathologies.

CONCLUSION

On MR images, tubal primaries almost always exhibited ovarian or peritoneal cancer pattern, but rarely exhibited fallopian tube cancer pattern. MR findings could not accurately differentiate between tubal and ovarian primaries; therefore, histopathologic investigation is essential for determination of the primary site of extrauterine HGSCs.

Narrative review on serous primary peritoneal carcinoma of unknown primary site: four questions to be answered

Serous peritoneal papillary carcinoma (SPPC) represents a particular cancer of unknown primary (CUP) entity that arises in the peritoneal surface lining the abdomen and pelvis without a discriminative primary tumor site. In this review, we discuss the validity of SPPC as a distinct entity. Clinically, patients with SPPC are older, have higher parity and later menarche, are more often obese and probably have poorer survival compared to those with primary ovarian cancer. Pathologically, SPPC is more anaplastic and multifocal, unlike primary ovarian cancer which is commonly unifocal. Biologically, it presents a higher expression of proliferative signals and similar cell cycle and DNA repair protein expression. These differences hint towards SPPC and primary ovarian cancer being as a spectrum of disease. Patients with SPPC are traditionally managed similarly to stage III–IV ovarian cancer. The recommended approach integrates aggressive cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, and systemic chemotherapy to remove the macroscopic tumor, eradicate the microscopic residual disease, and control the microscopic metastasis. However, the available evidence lacks proper randomized or prospective studies on SPPC and is limited to retrospective series. The diligent identification of SPPC is warranted to design specific clinical trials that eventually evaluate the impact of the new therapeutics on this distinct entity.

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.

Bilateral Ovarian Tumors on MRI: How Should We Differentiate the Lesions?

Background

We investigated the distinguishing pathological features of bilateral ovarian tumors using magnetic resonance (MR) imaging.

Methods

Eighty-six patients with bilateral ovarian tumors on MR imaging were evaluated. The pathological diagnosis was investigated, and the results were subjected to statistical analysis using Mann-Whitney U test, Fisher's exact test, Chi-squared test and receiver operating characteristic (ROC) curve to determine the features useful for the differentiation of distinct types of lesions.

Results

The diagnosis of bilateral ovarian tumors was confirmed in eighty-one patients and the majority of the lesions were further classified into serous carcinoma (n = 36), mature teratoma (n = 20) and metastasis (n = 12). We assessed the existence of factors useful for the MR imaging differentiation between metastasis and serous carcinoma or primary malignant ovarian tumors. Cancer antigen (CA) 125 serum level and maximum tumor diameter were significantly different between metastasis and serous carcinoma and similarly, between metastasis and primary malignant ovarian tumors. MR imaging morphology, ascites and peritoneal implants did not show any significant difference between the different types of lesions.

Conclusion

Within our patient cohort, most bilateral ovarian tumor lesions were determined to be serous carcinoma, mature teratoma or metastasis. CA 125 serum level and maximum tumor diameter are useful markers for the differentiation between metastasis and serous carcinoma or primary malignant ovarian tumors.

BRCA-associated Cancers: Role of Imaging in Screening, Diagnosis, and Management

Harmful mutations of the BRCA tumor suppressor genes result in a greater lifetime risk for malignancy-breast and ovarian cancers in particular. An increased risk for male breast, fallopian tube, primary peritoneal, pancreatic, prostate, and colon cancers also has been reported. The BRCA gene is inherited in an autosomal dominant pattern and tends to be highly penetrant; thus, there is an increased incidence of these cancers in affected families. Compared with sporadic tumors, BRCA-associated malignancies have unique manifestations, clinical features, and pathologic profiles. Manifestation at an early patient age, high-grade tumors, and an aggressive clinical course are common features of BRCA-associated malignancies. Understanding the behavior of these cancers aids in identification of affected individuals and families, who can then make informed decisions regarding their future health. Enhanced screening, prophylactic surgery, and chemoprevention are options for managing cancer risk factors in these individuals. Imaging has an important role in the screening, evaluation, staging, and follow-up of BRCA-associated malignancies. Supplemental screening of BRCA mutation carriers often begins at an early age and is critical for early and accurate cancer diagnoses. The authors review the etiopathogenesis and imaging features of BRCA-associated malignancies, the importance of a multidisciplinary approach to determining the diagnosis, and the treatment of patients who have these mutations to improve their outcomes. ^© RSNA, 2017.

Long-term survival of high-grade primary peritoneal papillary serous adenocarcinoma: a case report and literature review

Background

Primary peritoneal papillary serous carcinoma (PPPSC) is an uncommon disease which has a high malignancy and a poor prognosis.

Case presentation

We report here a long-term survival case of PPPSC with postoperative lung metastasis. A 62-year-old female patient with PPPSC was administered two cycles of neoadjuvant chemotherapy (NAC) followed by cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) and six cycles of platinum-based (docetaxel + carboplatin) intraperitoneal chemotherapy postoperatively. The patient reached a complete remission at the completion of primary treatment. Malignant thoracic effusion and lung metastasis developed 5 months after the treatment. The patient underwent video-assisted thoracoscopic surgery plus hyperthermic intrapleural chemotherapy.

Conclusions

Up to present, the patient has been survived with tumor for over 86 months with a good performance status, with only encapsulated effusion found at the latest follow-up. As a relatively new regime, the application of CRS + HIPEC in our patient has been proved example for MPE management, although more large-scale studies are needed to substantiate its efficiency and safety.

Revised FIGO staging system for cancer of the ovary, fallopian tube, and peritoneum: important implications for radiologists

Ovarian cancer is the seventh most common cancer diagnosis among women worldwide. The International Federation of Gynecology and Obstetrics recently significantly revised staging criteria for cancer of the ovary. The latest revision was based on the concept that high-grade serous tubal intraepithelial carcinoma (STIC) may be the origin of some high-grade serous carcinomas of the ovary and peritoneum. Therefore, staging criteria for the ovary, fallopian tube, and peritoneum have been unified. Understanding this background and other important revised points are essential for radiologists concerned with imaging diagnosis in gynecologic oncology. Through this review, we introduce the STIC theory and show examples of diseases in accordance with the new staging criteria based on magnetic resonance imaging (MRI) and computed tomography (CT) results.

Primary peritoneal serous carcinoma: a rare case and palliative approach

Primary peritoneal serous carcinoma (PPSC) is a rare primary malignancy that diffusely involves the peritoneum, indistinguishable clinically and histopathologically from primary serous ovarian carcinoma. The origin of PPSC has not been well characterized. Here we present a case of PPSC diagnosed in ultrasonography-guided fine needle aspiration cytology (FNAC) in a 76- old female presenting with ascites, abdominal pain, distension and constipation. PPSC is an unusual tumour but cytomorphology is distinctive enough to diagnose preoperatively. In the case report hereby described PPSC is an inoperable malignancy, hence chemotherapy and palliative care are the only offered treatment.

Peritonealkarzinose: Präoperative Diagnostik und Patientenselektion

<b><i>Hintergrund: </i></b>Die zytoreduktive Chirurgie und die hypertherme intraperitoneale Chemotherapie spielen inzwischen eine zunehmend wichtige Rolle in der Therapie der Peritonealkarzinose bei zahlreichen Tumorentitäten. <b><i>Methode: </i></b>Die wichtigsten Selektionskriterien werden erläutert. <b><i>Ergebnisse: </i></b>Neben dem Alter und Allgemeinzustand sowie der Auswahl geeigneter Tumorentitäten spielt die Tumorlast, die möglichst exakt bereits vor der Operation abgeschätzt werden sollte, eine entscheidende Rolle. <b><i>Schlussfolgerung: </i></b>Entscheidend ist eine Selektion geeigneter Patienten, um den onkologischen Benefit zu steigern und die Morbidität zu verringern.

Peritoneal carcinomatosis: comparison of dynamic contrast-enhanced magnetic resonance imaging with surgical and histopathologic findings

OBJECTIVE

In patients with peritoneal carcinomatosis (PC) accurate preoperative assessment is essential to determine indication and surgical procedure to ensure optimal outcome. Purpose of our study was to assess the diagnostic accuracy (DA) of multiphasic dynamic contrast-enhanced MRI to determine the extent of PC in correlation with surgical and histopathological findings.

MATERIALS AND METHODS

14 Patients with proven PC were examined on a 1.5T system before peritonectomy and hyperthermic intraperitoneal chemotherapy. Patient preparation included oral application of 2000 mL mannitol solution and 40 mg butylscopolaminiumbromid i.v. Coronal contrast-enhanced multiphasic dynamic T1w 3D gre sequences (T1W DCE) (0.15 mmol Gd-chelate/kg bw) covering the whole abdomen were acquired (TR 2.9 ms, TE 1.1 ms, resolution 2.0 × 2.0 × 1.8 mm, FOV 400 × 400 mm). MRI was assessed by two radiologists and correlated with surgical exploration (SE) and histopathology for each segment based on the peritoneal cancer index proposed by Sugarbaker et al.

RESULTS

In total, 182 segments were evaluated. PC was found in 118/121 of 182 segments (reader 1/2) by MRI and in 131 segments by SE. In 4/7 segments MRI was false positive. False negative segments 17/17 in MRI did not result in irresectability. The positive predictive value for PC per segment of MRI was 97%/94%, the negative predictive value 73%/72%, the sensitivity 87%/87% and the specificity 92%/86%. The DA was 88%/87%.

CONCLUSION

T1W DCE is an accurate and clinical valuable tool for the preoperative assessment of peritoneal tumor spread.

Epithelioid Lesions of the Serosa

Context.—Diagnosing epithelioid serosal lesions remains a challenge because numerous different processes—primary or secondary, benign or malignant—occur in body cavities, some of which are very rare.

Objectives.—To review the newest literature and to describe the morphologic criteria and immunohistochemical markers that are useful for distinguishing epithelioid serosal lesions.

Data Sources.—Previously published literature concentrating on the newest research findings. Earlier reviews are principally referred to for established diagnostic criteria.

Conclusions.—Immunohistochemistry with a panel of antibodies has made the diagnosis of epithelioid serosal lesions very reliable. When deciding on antibodies used in differential diagnosis, it is important to consider tumor location, clinical and radiologic information, and morphologic features. Immunohistochemistry is less useful in the differential diagnosis of benign versus malignant mesothelial lesions. The diagnosis of benign versus malignant mesothelial proliferations still relies on the histologic criteria of invasion.

Endobronchial metastasis from primary papillary serous carcinoma of the peritoneum

A 59-year-old woman was admitted to our hospital with a left lower lobe opacity and mediastinal shift on the chest X-ray. She had been complaining of intermittent nonproductive cough and exertional dyspnea. Chest computed tomography (CT) showed an endobronchial tumor of the left main to the lower bronchus, atelectasis of the left lower lobe, and mediastinal shift. Bronchoscopy revealed a polypoid tumor at the distal portion of the left main bronchus that occluded the bronchus. Biopsy specimens from the endobronchial tumor were shown to be serous papillary adenocarcinoma. Since the patient had been treated surgically for primary papillary serous carcinoma of the peritoneum (PSCP) 10 years earlier, immunohistochemical examinations were performed. The diagnosis of endobronchial metastasis of PSCP was confirmed by immunohistochemical staining with cancer antigen 125 (CA125), vimentin, and Wilms tumor-1 (WT-1). This is a rare case of endobronchial metastasis from PSCP.

Primary peritoneal carcinoma: computed tomography and magnetic resonance findings

OBJECTIVE

To present computed tomography (CT) and magnetic resonance imaging (MRI) findings of primary peritoneal carcinoma (PPC) at initial presentation (IP) and recurrent disease (RD).

METHODS

We studied 15 consecutive female patients (age range, 47-83 years; mean, 66.2 years) with pathologically proven PPC who underwent CT and/or MRI between July 2000 and December 2005. Preoperative radiological evaluation and postoperative follow-up was done with CT and/or magnetic resonance studies. All CT and MRI studies were evaluated retrospectively, independently, and blindly by 2 radiologists for the imaging findings of PPC.

RESULTS

The imaging findings were as follows: ascites, 2 of 2 at IP, 9 of 10 at RD; peritoneal thickening and enhancement, 1 of 2 at IP, 9 of 10 at RD; peritoneal nodules or bulky mass lesions, 1 of 2 at IP, 8 of 10 at RD; lymph node involvement, 1 of 2 at IP, 3 of 10 at RD; and distant metastases, 1 of 10 at RD.

CONCLUSION

Ascites, peritoneal thickening and enhancement, and peritoneal nodules or bulky mass lesions were the most frequent findings of PPC. Recurrent disease revealed similar findings compared with the IP.

From the archives of the AFIP: primary peritoneal tumors: imaging features with pathologic correlation

Primary peritoneal tumors are uncommon lesions that arise from the mesothelial or submesothelial layers of the peritoneum. Primary malignant mesothelioma, multicystic mesothelioma, primary peritoneal serous carcinoma, leiomyomatosis peritonealis disseminata, and desmoplastic small round cell tumor are the most prominent of these rare lesions. Primary malignant mesothelioma is a highly aggressive malignancy that occurs most commonly in older men and that has a strong association with high levels of asbestos exposure. It manifests most often as diffuse sheetlike or nodular thickening of the peritoneal surfaces, but it may occasionally be a localized mass. Multicystic mesothelioma occurs most frequently in women and has benign or indolent biologic behavior in the majority of patients. It is a multilocular cystic mass that arises from the pelvic peritoneal surfaces. Primary peritoneal serous carcinoma occurs almost exclusively in women. It is histologically identical to ovarian serous carcinoma and may be indistinguishable from metastatic ovarian carcinoma at imaging studies. Leiomyomatosis peritonealis disseminata is a rare, benign proliferative process that also occurs exclusively in women and is characterized by multiple smooth muscle nodules throughout the peritoneum. Desmoplastic small round cell tumor is a highly aggressive malignancy of unknown origin that occurs most often in the peritoneal cavity of young men. This unusual group of tumors is linked together by a common site of origin and imaging manifestations that mimic those of peritoneal carcinomatosis. Knowledge of the spectrum of imaging findings in this group of primary peritoneal tumors, along with their clinical and pathologic characteristics, is important in the evaluation of patients with diffuse peritoneal disease.

MR imaging of the peritoneal spread of malignancy

MR imaging provides a highly sensitive and accurate means to depict tumor involving the peritoneum and bowel serosa. The ability of MR imaging to depict subtle peritoneal metastases plays a critical role in diagnosing and monitoring the oncologic patient with known or suspected peritoneal spread of malignancy. In this review I will describe the mechanisms of peritoneal tumor spread, and MR techniques and protocols for peritoneal imaging. A detailed description of the MR appearance of peritoneal tumor at different anatomic sites will be provided followed by a discussion of clinical applications for MR imaging of peritoneal malignancy.

Primary serous papillary carcinoma of the retroperitoneum: magnetic resonance imaging findings with pathologic correlation

The incidence of a primary serous papillary carcinoma of the retroperitoneum is extremely rare. We present a case of the tumour in an adult simulating an adrenal mass with MRI findings and histopathological correlation.