Patterns of peritoneal spread of tumor in the abdomen and pelvis

Gastric Outlet Obstruction as a First Symptom of a Non-Muscle Invasive Bladder Cancer (NMIBC) Progression-A Case Report

BACKGROUND

Metastatic disease of a urinary bladder cancer localized in the upper abdomen is very rare. This case report describes the first patient with a urinary bladder cancer progression, initially presenting as a gastric outlet obstruction due to peritoneal carcinomatosis.

CASE

We present the case of a 78-years-old male patient who was admitted to Hospital St. Josef Braunau in Austria with persistent vomiting. In the medical history, the most prominent finding was a diagnosed high-risk NMIBC. At the time, patient was between 2. and 3. BCG maintenance instillation cycle, following two transurethral resections. Routine follow-up cystoscopy 1 month before admission to our department showed no evidence of disease recurrence. Due to the therapy resistant vomiting, gastroscopy was performed, revealing duodenal stenosis without mucosal changes. Subsequently performed abdominal CT-scan showed homogenous swelling of the mesenteric fat tissue around duodenum, spreading retroperitoneal to both kidneys. In the absence of the typical peritoneal carcinomatosis features, the finding was firstly described as an inflammation of mesenteric fat or panniculitis mesenterialis. Further deterioration of patient's condition and later occurred bilateral hydronephrosis raised a suspicion of peritoneal carcinomatosis. Consequently, conducted laparoscopic exploration confirmed the suspicion describing the tissue conglomerate typical for peritoneal carcinomatosis surrounding the duodenum. Pathohistological analysis of taken samples proved urothelial cancer cells, confirming the diagnosis of metastatic bladder cancer disease.

CONCLUSION

This case report presents a very unusual presentation of metastatic urinary bladder cancer that could help clinicians to consider this diagnosis when encountering similar clinical features.

The Peritoneum: Anatomy, Pathologic Findings, and Patterns of Disease Spread

Disease spread in the abdomen and pelvis generally occurs in a predictable pattern in relation to anatomic landmarks and fascial planes. Anatomically, the abdominopelvic cavity is subdivided into several smaller spaces or compartments by key ligaments and fascial planes. The abdominal cavity has been traditionally divided into peritoneal, retroperitoneal, and pelvic extraperitoneal spaces. Recently, more clinically relevant classifications have evolved. Many pathologic conditions affect the abdominal cavity, including traumatic, inflammatory, infectious, and neoplastic processes. These abnormalities can extend beyond their sites of origin through various pathways. Identifying the origin of a disease process is the first step in formulating a differential diagnosis and ultimately reaching a final diagnosis. Pathologic conditions differ in terms of pathways of disease spread. For example, simple fluid tracks along fascial planes, respecting anatomic boundaries, while fluid from acute necrotizing pancreatitis can destroy fascial planes, resulting in transfascial spread without regard for anatomic landmarks. Furthermore, neoplastic processes can spread through multiple pathways, with a propensity for spread to noncontiguous sites. When the origin of a disease process is not readily apparent, recognizing the spread pattern can allow the radiologist to work backward and ultimately arrive at the site or source of pathogenesis. As such, a cohesive understanding of the peritoneal anatomy, the typical organ or site of origin for a disease process, and the corresponding pattern of disease spread is critical not only for initial diagnosis but also for establishing a road map for staging, anticipating further disease spread, guiding search patterns and report checklists, determining prognosis, and tailoring appropriate follow-up imaging studies. ©RSNA, 2024 Supplemental material is available for this article.

Imaging of Peritoneal Carcinomatosis in Advanced Ovarian Cancer: CT, MRI, Radiomic Features and Resectability Criteria

PC represents the most striking picture of the loco-regional spread of ovarian cancer, configuring stage III. In the last few years, many papers have evaluated the role of imaging and therapeutic management in patients with ovarian cancer and PC. This paper summed up the literature on traditional approaches to the imaging of peritoneal carcinomatosis in advanced ovarian cancer, presenting classification systems, most frequent patterns, routes of spread and sites that are difficult to identify. The role of imaging in diagnosis was investigated, with particular attention to the reported sensitivity and specificity data-computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT)-and to the peritoneal cancer index (PCI). In addition, we explored the therapeutic possibilities and radiomics applications that can impact management of patients with ovarian cancer. Careful staging is mandatory, and patient selection is one of the most important factors influencing complete cytoreduction (CCR) outcome: an accurate pre-operative imaging may allow selection of patients that may benefit most from primary cytoreductive surgery.

Gastric adenocarcinoma: A review of the TNM classification system and ways of spreading

Gastric cancer is the fifth most common cancer in the world. The most common histologic subtype is adenocarcinoma. Gastric adenocarcinomas are staged using the American Joint Committee on Cancer's 8th TNM classification. The perigastric ligaments, mesentery, omentum, and potential spaces between the parietal and visceral peritoneal linings play are important structures for staging. The spread of disease is influenced by the location of the tumor within the stomach, as well as by the anatomy related to the ligaments and lymph vessels. CT is the imaging modality of choice for the preoperative clinical staging of gastric cancer, and it is essential for planning treatment. To be able to do an adequate imaging workup, radiologists need to know the different pathways through which gastric cancer can spread: lymphatic, subperitoneal, direct invasion, transperitoneal, hematogenous, and extramural venous invasion.

Morrison's Pouch: Anatomy and Radiological Appearance of Pathological Processes

Morrison's pouch is the intraperitoneal space in the supramesocolic compartment located between the right liver lobe and right kidney. Pathological conditions that can involve this peritoneal space include fluid collections, infectious or inflammatory processes, and neoplasms. Frequent involvement by disease entities can be attributed to its dependent location, communication with the inframesocolic compartment, close proximity to the adjacent organs and peritoneal fluid dynamics. Knowledge of the appearance of pathological entities on various imaging modalities helps the radiologist in making the correct diagnosis.

Peritoneal malignancy: anatomy, pathophysiology and an update on modern day imaging

With increasing subspecialised experience in radical cytoreductive surgery and intra-abdominal chemotherapy for peritoneal malignancy, outcomes have improved significantly in selected patients. The surgery and the treatment regimens are radical and therefore correct patient selection is critical. The radiologist plays a central role in this process by estimating, as precisely as possible, the pre-treatment disease burden. Because of the nature of the disease process, accurate staging is not an easy task. Tumour deposits may be very small and in locations where they are very difficult to detect. It must be acknowledged that no form of modern day imaging has the capability of detecting the smallest peritoneal nodules, which may only be visible to direct inspection or histopathological evaluation. Nonetheless, it behoves the radiologist to be as exact and precise as possible in the reporting of this disease process. This is both to select patients who are likely to benefit from radical treatment, and just as importantly, to identify patients who are unlikely to achieve adequate cytoreductive outcomes. In this review, we outline the patterns of spread of disease and the anatomic basis for this, as well as the essential aspects of reporting abdominal studies in this patient group. We provide an evidence-based update on the relative strengths and limitations of our available multimodality imaging techniques namely CT, MRI and positron emission tomography/CT.

Peritoneal metastases found in routinely resected specimens after cytoreductive surgery and heated intraperitoneal chemotherapy

INTRODUCTION

Peritoneal metastases (PM) originating from colorectal cancer (CRC) and pseudomyxoma peritonei (PMP) can be treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Certain sites in the peritoneal cavity are prone to contain PM and are, therefore, routinely resected. The aim of this study is to investigate the frequency of disease in CRS specimens routinely resected. Secondly, to investigate if the risk of finding PM in routinely resected specimen is associated with involvement of anatomic related peritoneal areas.

MATERIALS AND METHODS

This study investigated 433 patients diagnosed with PMP (n = 119) or PM from CRC (n = 314) and operated with CRS + HIPEC between June 2006 and November 2020 at a national center. Baseline data were prospectively registered. Pathology reports were reviewed for the presence of metastases in the routinely resected umbilicus, ligamentum teres hepatis, ovaries and greater omentum. Tumor extent was estimated using the Dutch region count.

RESULTS

PM was found in 14.7% of umbilical resections, in 17.4% of the resected ligamentum teres hepatis, in 48.2% of the resected ovaries and in 49.5% of the greater omentum specimens. We found an association between macroscopic disease involvement of the nearest region and risk of PM found in the related resections. Seven of 31 women with no macroscopically visible disease in the pelvis had PM diagnosed in the resected ovaries.

CONCLUSIONS

A substantial proportion of routine resections held histologic verified PM. Our results may advocate for a routinely performed resection of the umbilicus, ligamentum teres hepatis, ovaries and greater omentum.

Early stage epithelial ovarian cancer metastasis through peritoneal fluid circulation

BACKGROUND

Although epithelial ovarian cancer (EOC) spreads through peritoneal circulation, all patients with clinical early-stage ovarian cancer (OC) benefit from routine surgical staging is still unclear.

METHODS

This cross-sectional study used data from medical records of patients with clinical early-stage EOC who received complete surgical staging from 2006 to 2016 at our hospital. We excluded patients with non-epithelial OC or with stage IV disease.

RESULTS

Among 50 patients with clinical early-stage EOC who underwent surgical staging, biopsies showed EOC cells in peritoneal fluid for 12 patients (24%), in peritoneal tissue for ten patients (20%), and omental tissue for eight patients (16%). Of those 50 patients, 40 patients had undergone peritoneal biopsies, and the other five patients also had omental biopsies. The results showed that only one (2.5%) from 40 patients with peritoneal biopsy and three (6.7%) from 45 patients with omental biopsy had no visible nodules. From cytology examination, 3 out of 26 patients (11.5%) showed positive cytology from peritoneal washing.

CONCLUSIONS

Routine peritoneal biopsies do not seem advantageous for patients with clinical early-stage EOC as negative visible nodules with positive biopsy results were only 1 in 40 cases. However, further study with a larger cohort is needed to obtain more information on peritoneal fluid metastasis patterns.

Diagnostic value of diffusion-weighted imaging/magnetic resonance imaging for peritoneal metastasis from malignant tumor: A systematic review and meta-analysis

BACKGROUND

Previous meta-analyses examined either multiple tools for the diagnosis of peritoneal metastases (PMs), but not diffusion-weighted imaging (DWI), or included only 1 tumor type. This study aimed to determine the summary diagnostic value of DWI/magnetic resonance imaging in determining PMs originating from various tumors.

METHODS

PubMed, Embase, and Cochrane library were searched for available papers up to 2019/12. Pooled estimates for sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and accuracy were calculated using random-effects models.

RESULTS

Ten studies were included and could be used to calculate the pooled sensitivity and specificity. The pooled sensitivity of DWI for PMs was 89% (95% confidence interval [CI]: 83%-93%). The pooled specificity was 86% (95% CI: 79%-91%). When considering only the retrospective studies, the pooled sensitivity of DWI for PMs was 85% (95% CI: 81%-89%). The pooled specificity was 84% (95% CI: 72%-92%). When considering only the studies about gastrointestinal tumors, the pooled sensitivity of DWI for PMs was 97% (95% CI: 68%-100%). The pooled specificity was 86% (95% CI: 69%-95%). No publication bias was observed (P = dd.27).

CONCLUSION

DWI magnetic resonance imaging is highly sensitive and specific for the detection of PMs from various abdominal cancers.

The Lesser Sac and Foramen of Winslow: Anatomy, Embryology, and CT Appearance of Pathologic Processes

OBJECTIVE. This article reviews the embryologic development, relevant anatomy, and imaging features, on CT, of pathologic processes involving the lesser sac and foramen of Winslow. CONCLUSION. The lesser peritoneal sac is an intricate anatomic region involved in many disease processes. It is a significant conduit for the spread of disease within the peritoneal cavity. The spectrum of pathologic processes pertaining to the lesser sac can be classified on the basis of the type of involvement, such as a fluid collection (e.g., transudate, exudate, bile, and blood), a mass (e.g., neoplastic or nonneoplastic conditions and lymphadenopathy), or an internal hernia into the lesser sac.

The Morphological Analysis of Cells in the Peritoneal Washing Fluids of Patients with Gastric Cancer

The cytology of peritoneal washing fluids for gastric cancer is the most basic method for judging peritoneal micrometastasis. However, the clinical value of this method is not clear at present. A retrospective analysis was performed on 277 patients with pathologically proven and surgically treated gastric cancer. The peritoneal washing fluids were collected after opening the abdomen and before the operation, and were sent to the cytology laboratory for screening of occult cancer cells in the collected washing fluids. The number of cases diagnosed as cancer cells, reactive mesothelial cells, serosal balls, and traumatic mesothelial cells were 42, 18, 27, and 190, respectively. Typical adenocarcinoma cell nests were found in eight of 10 T4b samples, whereas 34 cases of cancer cells in T3 and T4a showed that these cell nests usually contained mesothelial cells, and the three-dimensional stereoscopic sense of the nests was not obvious. In the specific subcellular morphological changes of both reactive mesothelial cells and serosal balls, the changes of both the contour of nuclear membrane and the polarity of cell alignment were present only in stage T3 and T4a. The presence or absence of mesothelial cells in the nests of cancer cells and the changes of the contour of nuclear membrane and of the polarity of cell alignment in reactive mesothelial cells or serosal balls may help us to predict the depth of invasion of cancer cells.

Peritoneal Carcinomatosis in Well-Differentiated Small-Intestinal Neuroendocrine Tumors with Mesenteric Tumor Deposits

OBJECTIVE

Well-differentiated small-intestinal neuroendocrine tumors (SI-NETs) tend to be biologically indolent. Despite this tendency, they have a predilection for metastasis. Peritoneal involvement is quite common as is unfortunately peritoneal carcinomatosis (PC). PC is a dreaded metastatic complication due to the significant morbidity it creates for patients as well as well as increasing their mortality risk. The risk factors for PC development in SI-NETs remain understudied; however, one such factor may be the presence of mesenteric tumor deposits (MTDs).

METHODS

We performed a retrospective analysis on 208 well-differentiated SI-NET patient samples, the majority with mesenteric masses, from the pathology archives of Vanderbilt University Medical Center. We sought to explore whether MTD presence was associated with PC, what other patient determinants were associated with PC and prognostic implication of these determinants.

RESULTS

Patients with MTDs had an OR of 3.9 (CI 1.6, 10.9) for PC compared to patients without MTDs in the analysis. Patients who developed PC fared more poorly than those who did not (p=0.044).

CONCLUSION

Our analysis, to the best of our knowledge, is the first to demonstrate an association between MTD presence and PC in this patient subgroup. We believe this finding warrants prospective evaluation given the possible therapeutic implications of being able to stratify SI-NET patients by their risk for developing PC based upon MTD presence.

Imaging of infracolic and pelvic compartment by linear EUS

The peritoneal cavity is subdivided into supracolic and infracolic compartments by transverse mesocolon, which attaches the colon to the posterior abdominal wall. Infracolic compartment is subdivided into right and left compartment by small bowel mesentery. Left infracolic space freely communicates with pelvic compartment. The infracolic compartment contains the coils of small bowel which is separated from paracolic gutter on either side by ascending and descending colon. Pelvic compartment mainly contains bladder, rectum and genital organ (prostate, seminal vesicle in male and uterus in female). The evaluation of different compartments of peritoneum is gaining importance in multimodality imaging. It has become essential that clinicians and endosonographers thoroughly understand the peritoneal spaces and the ligaments and mesenteries that form their boundaries in order to localize disease to a particular peritoneal/subperitoneal space and formulate a differential diagnosis on the basis of that location. In this article we describe the applied EUS anatomy of peritoneal ligaments, infracolic and pelvic compartments of peritoneum and there technique of imaging from stomach, duodenum, sigmoid colon and rectum. Imaging from stomach images the infracolic compartment through transverse mesocolon, imaging from duodenum images the infracolic compartment through the mesentery and imaging from rectum and sigmoid images the infracolic and pelvic compartments through the sigmoid mesocolon and pelvic peritoneum.

Pre-therapy CT scan showing peritoneal thickening from metastatic renal pelvis carcinoma patients

We investigated clinical significance of peritoneal thickening from metastatic renal pelvis based on pretherapy computed tomography (CT) scan findings. The criteria for inclusion were as follows: (1) pathology and CT scan confirmed metastatic renal pelvis carcinoma and (2) peritoneal thickening based on pre-therapy CT scan findings. We investigated the route of spread, gastrointestinal (GI) complications, and response to chemotherapy. A total of 68 cases were enrolled in this study, including seven patients with liver metastases and three with abdominal wall invasion. GI complications included obstruction in ten patients and bleeding in three. Response to chemotherapy demonstrated by reduced peritoneal thickening was noted in 24 patients. In conclusion. peritoneal thickening with clinical suspicion of peritoneal involvement can get indirect evidence from route of spread (liver or abdominal wall), GI complications (obstruction or bleeding) or response to chemotherapy (obvious decrease peritoneal thickening) from metastatic renal pelvis carcinoma patients. Pretherapy CT scan with peritoneal thickening should be alert that tumor has spread to the peritoneum.

Under-stage and Overlook of Peritoneal Spread from Bladder Urothelial Carcinoma

BACKGROUND/AIM

Bladder cancer can spread from the sub-peritoneal space superior and posterolateral to the peritoneal cavity via the peritoneal lining. The aim of this study was to improve the identification of peritoneal spread from bladder urothelial carcinoma based on computed tomography (CT) scans.

MATERIALS AND METHODS

This is a retrospective study including patients selected with the following criteria: (i) pathology-confirmed urothelial carcinoma; (ii) peritoneal spread identified on CT scans from axial and corona views, either initially or after radical/partial cystectomy, concomitant chemoradiotherapy (CCRT), or radiotherapy. One hundred and fifty-nine cases met the selection criteria.

RESULTS

Routes of spread to the peritoneum included the superior to anterior direction in 59 patients (37%), the superior to posterolateral direction in 19 (12%), and the superior to both anterior and posterolateral directions in 81 (51%). Invasion of specific sites included the abdominal wall in 101 patients (70%), bowel/mesentery in 84 (53%), prostate, uterus, and rectum in 30 (19%), and circumferential tumors that outlined the whole bladder wall in 59 (37%). Initial modes of therapy were chemotherapy in 86 patients (54%), cystectomy in 55 (35%), CCRT in eight (5%), radiotherapy in two (1%), and no therapy in eight (5%). Peritoneal spread due to under-staging (clinical/pathological stage) after local therapy was found in 84 patients (53%).

CONCLUSION

Initial pre-therapeutic staging is easily overlooked regarding peritoneal spread from bladder urothelial carcinoma. Combined axial and coronal views of CT scans can help identify peritoneal involvement.

The peritoneal "soil" for a cancerous "seed": a comprehensive review of the pathogenesis of intraperitoneal cancer metastases

Various types of tumors, particularly those originating from the ovary and gastrointestinal tract, display a strong predilection for the peritoneal cavity as the site of metastasis. The intraperitoneal spread of a malignancy is orchestrated by a reciprocal interplay between invading cancer cells and resident normal peritoneal cells. In this review, we address the current state-of-art regarding colonization of the peritoneal cavity by ovarian, colorectal, pancreatic, and gastric tumors. Particular attention is paid to the pro-tumoral role of various kinds of peritoneal cells, including mesothelial cells, fibroblasts, adipocytes, macrophages, the vascular endothelium, and hospicells. Anatomo-histological considerations on the pro-metastatic environment of the peritoneal cavity are presented in the broader context of organ-specific development of distal metastases in accordance with Paget's "seed and soil" theory of tumorigenesis. The activity of normal peritoneal cells during pivotal elements of cancer progression, i.e., adhesion, migration, invasion, proliferation, EMT, and angiogenesis, is discussed from the perspective of well-defined general knowledge on a hospitable tumor microenvironment created by the cellular elements of reactive stroma, such as cancer-associated fibroblasts and macrophages. Finally, the paper addresses the unique features of the peritoneal cavity that predispose this body compartment to be a niche for cancer metastases, presents issues that are topics of an ongoing debate, and points to areas that still require further in-depth investigations.

Synchronous peritoneal metastases of small bowel adenocarcinoma: Insights into an underexposed clinical phenomenon

BACKGROUND

The aim of this population-based study was to provide insight into the incidence, risk factors and treatment-related survival of patients with peritoneal metastases (PM) of small bowel adenocarcinoma (SBA).

METHODS

Data from the Netherlands Cancer Registry were used. All patients diagnosed with SBA between 2005 and 2014 were included. The influence of patient and tumour characteristics on the odds of developing PM was analysed. Subsequently, for all further analyses, patients without synchronous PM of SBA were excluded. The log-rank test and Kaplan-Meier analyses were conducted to estimate survival, and the Cox proportional hazards model was used to evaluate the risk of death.

RESULTS

Of the 1428 included patients diagnosed with SBA, 181 (13%) presented with synchronous PM. Synchronous PM was found in 9% of the duodenal tumours and in 17% of the more distal tumours. Median overall survival of all patients with PM was 5.9 months, whereas survival of both 11 months was observed in patients treated with primary tumour resection or palliative chemotherapy and 32 months after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS+HIPEC). Poor prognostic factors for survival were age ≥70 years (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.1-2.2), systemic metastases other than PM (HR 2.0, 95% CI 1.4-2.9) and an advanced (HR 1.9, 95% CI 1.3-3.0) or unknown T-stage (HR 2.1, 95% CI 1.2-3.5).

CONCLUSIONS

Synchronous PM was frequently encountered in SBA. Without treatment, prognosis was extremely poor. Survival was higher after primary tumour resection, palliative chemotherapy and CRS+HIPEC, but selection bias probably played a significant role calling for further clinical research.

Unique cellular interactions between pancreatic cancer cells and the omentum

Pancreatic cancer is a common cause of cancer-related mortality. Omental spread is frequent and usually represents an ominous event, leading to patient death. Omental metastasis has been studied in ovarian cancer, but data on its role in pancreatic cancer are relatively scarce and the molecular biology of this process has yet to be explored. We prepared tissue explants from human omental fat, and used conditioned medium from the explants for various in vitro and in vivo experiments designed to evaluate pancreatic cancer development, growth, and survival. Mass spectrometry identified the fat secretome, and mRNA array identified specific fat-induced molecular alternations in tumor cells. Omental fat increased pancreatic cancer cellular growth, migration, invasion, and chemoresistance. We identified diverse potential molecules secreted by the omentum, which are associated with various pro-tumorigenic biological processes. Our mRNA array identified specific omental-induced molecular alternations that are associated with cancer progression and metastasis. Omental fat increased the expression of transcription factors, mRNA of extracellular matrix proteins, and adhesion molecules. In support with our in vitro data, in vivo experiments demonstrated an increased pancreatic cancer tumor growth rate of PANC-1 cells co-cultured for 24 hours with human omental fat conditioned medium. Our results provide novel data on the role of omental tissue in omental metastases of pancreatic cancer. They imply that omental fat secreted factors induce cellular reprogramming of pancreatic cancer cells, resulting in increased tumor aggressiveness. Understanding the mechanisms of omental metastases may enable us to discover new potential targets for therapy.

Intraperitoneal Administration of Neural Stem Cell-Nanoparticle Conjugates Targets Chemotherapy to Ovarian Tumors

Ovarian cancer is particularly aggressive once it has metastasized to the abdominal cavity (stage III). Intraperitoneal (IP) as compared to intravenous (IV) administration of chemotherapy improves survival for stage III ovarian cancer, demonstrating that concentrating chemotherapy at tumor sites has therapeutic benefit; unfortunately, IP therapy also increases toxic side effects, thus preventing its completion in many patients. The ability to target chemotherapy selectively to ovarian tumors while sparing normal tissue would improve efficacy and decrease toxicities. We have previously shown that tumor-tropic neural stem cells (NSCs) dramatically improve the intratumoral distribution of nanoparticles (NPs) when given intracerebrally near an orthotopic brain tumor or into a flank xenograft tumor. Here, we show that NPs either conjugated to the surface of NSCs or loaded within the cells are selectively delivered to and distributed within ovarian tumors in the abdominal cavity following IP injection, with no evidence of localization to normal tissue. IP administration is significantly more effective than IV administration, and NPs carried by NSCs show substantially deeper penetration into tumors than free NPs. The NSCs and NPs target and localize to ovarian tumors within 1 h of administration. Pt-loaded silica NPs (SiNP[Pt]) were developed that can be transported in NSCs, and it was found that the NSC delivery of SiNP[Pt] (NSC-SiNP[Pt]) results in higher levels of Pt in tumors as compared to free drug or SiNP[Pt]. To the best of our knowledge, this work represents the first demonstration that cells given IP can target the delivery of drug-loaded NPs.

Endoscopic ultrasound of peritoneal spaces

The peritoneal cavity is subdivided into supracolic and infracolic compartments by transverse colon and its mesocolon. The supracolic compartment contains the liver, spleen, stomach, and lesser omentum. The infracolic compartment contains the coils of small bowel surrounded by ascending, transverse, and descending colon and the paracolic gutters. The imaging of different compartments is possible by various methods such as ultrasound (US) and computerized tomography. The treating physicians should be familiar with the relevant radiological anatomy of different compartments and spaces as accurate localization of fluid collection/lymph node in peritoneal cavity greatly aids in selection of a treatment strategy. The role of endoscopic US (EUS) is emerging for detail evaluation of all parts of peritoneal cavity as it provides an easy access for fine-needle aspiration from different compartments of peritoneal cavity. In this review, we describe the techniques of evaluation of different parts of supracolic compartments of peritoneum by EUS.

Cysto-duodeno-colic ligament and its clinical relevance

During a routine dissection class for the undergraduate students at All India Institute of Medical Sciences, New Delhi, a rare uncommon variation of the peritoneal ligament was found. Information regarding variation in such type of accessory peritoneal reflections is necessary for anatomists, surgeons, and radiologists. Normally there was no peritoneal reflection between gallbladder, duodenum and transverse colon, but in the present case report, it was present and termed as cysto-duodeno-colic ligament. Knowledge of such variation is necessary during gallbladder surgeries and liver transplantation surgeries.

Role of Imaging in Peritoneal Surface Malignancies

Imaging plays a vital role in the evaluation of peritoneal malignancies. The presence of peritoneal metastases (PM) alters tumor staging, with direct implications in treatment choice and prognosis. Cytoreductive surgery (CRS) and Hyperthermic intraperitoneal chemotherapy (HIPEC) as a combined modality treatment have led to prolonged survival and even cure in selected patients with PM. Better outcomes are seen in patients with limited disease spread. Therefore, early diagnosis of peritoneal tumor seeding is essential. Despite significant advancement of technology, assessment of the origin of PM is often difficult, due partly to the complex peritoneal anatomy and partly due to the complex overlap of imaging features. Multidetector CT (MDCT) is the main stay due to its wide availbility, rapid evaluation, robust technique and good resolution. Imaging plays a vital role in selecting patients for the combined modality treatment. MRI is not as popular as CT due to limited availability, time required for the study and lack of experience with interpreting the results. PET-CT is useful in ruling out extra peritoneal disease and it is the CT component that is more reliable for predicting the disease extent. This article reviews the current use of various imaging modalities in various stages of treatment of patients with PM especially those undergoing CRS and HIPEC.

miR-200c Regulation of Metastases in Ovarian Cancer: Potential Role in Epithelial and Mesenchymal Transition

Among the gynecological malignancies, ovarian cancer is the most fatal due to its high mortality rate. Most of the identified cases are epithelial ovarian cancer (EOC) with five distinct subtypes: high-grade serous carcinoma, low-grade serous carcinoma, mucinous carcinoma, endometrioid carcinoma, and clear-cell carcinoma. Lack of an early diagnostic approach, high incidence of tumor relapse and the heterogenous characteristics between each EOC subtypes contribute to the difficulties in developing precise intervention and therapy for the patients. MicroRNAs (miRNAs) are single-stranded RNAs that have been shown to function as tumor suppressors or oncomiRs. The miR-200 family, especially miR-200c, has been shown to be implicated in the metastasis and invasion of ovarian carcinoma due to its functional regulation of epithelial-to-mesenchymal transition (EMT). This mini review is aimed to summarize the recent findings of the miR-200c functional role as well as its validated targets in the metastasis cascade of ovarian cancer, with a focus on EMT regulation. The potential of this miRNA in early diagnosis and its dual expression status are also discussed.

De-misty-fying the mesentery: an algorithmic approach to neoplastic and non-neoplastic mesenteric abnormalities

Mesenteric abnormalities are often incidentally discovered on cross-sectional imaging performed during daily clinical practice. Findings can range from the vague "misty mesentery" to solid masses, and the possible etiologic causes encompass a wide spectrum of underlying pathologies including infectious, inflammatory, and neoplastic processes. Unfortunately, the clinical and imaging findings are often non-specific and may overlap. This article discusses the various diseases that result in mesenteric abnormalities. It provides a framework to non-invasively differentiate these entities, when possible.

Cytoreductive Surgery and Peritonectomy Procedures

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has become widely accepted as an effective method of treating peritoneal metastases (PM) from various cancers. CRS performed with the goal of removing all the macroscopic disease and comprises of peritonectomy procedures and visceral resections. CRS is a technically challenging surgery that requires a considerable amount of skill and appropriate patient selection. This article is a review of the techniques and current recommendations for performing CRS.

Imaging of peritoneal ligaments by endoscopic ultrasound (with videos)

Double layered peritoneal folds or ligaments act as conduits for the passage of blood vessels in intraperitoneal organs and also provide a pathway for the spread of disease. It is difficult to identify these normal peritoneal folds at imaging. Computed tomography is the most common imaging modality used to detect diseases of the peritoneum. The ultrasound (US) has been also used for evaluation of diseases involving ligaments. Endoscopic ultrasound (EUS) is being increasingly used both for diagnostic and interventional purposes in abdomen. In this article, we have described the normal EUS anatomy of the peritoneal ligaments.

The normal transverse mesocolon and involvement of the mesocolon in acute pancreatitis: an MRI study

OBJECTIVE

To study the MRI findings of the normal transverse mesocolon and the involvement of the mesocolon in acute pancreatitis (AP) as well as the relationship between the involvement of the mesocolon and the severity of AP.

MATERIALS AND METHODS

Forty patients without pancreatic disorders were retrospectively analyzed to observe the normal transverse mesocolon using MRI; 210 patients with AP confirmed by clinical and laboratory tests were retrospectively analyzed using MRI to observe transverse-mesocolon involvement (TMI). The severity of TMI was recorded as zero points (no abnormalities and transverse-mesocolon vessel involvement), one point (linear and patchy signal in the transverse mesocolon) or two points (transverse-mesocolon effusion). The AP severity was graded by the MRI severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation II (APACHE II) scoring system. The correlations of TMI with MRSI and APACHE-II were analyzed.

RESULTS

In a normal transverse mesocolon, the display rates of the middle colic artery, the middle colic vein and the gastrocolic trunk on MRI were 95.0%, 82.5% and 100.0%, respectively. Of the 210 patients with AP, 130 patients (61.9%) had TMI. According to the TMI grading, 40%, 39% and 20% of the patients were graded at zero, one and two points, respectively. TMI was strongly correlated with the MRSI score (r = 0.759, P = 0.000) and the APACHE-II score (r = 0.384, P = 0.000).

CONCLUSION

MRI could be used to visualize transverse-mesocolon involvement. The severity of TMI could reflect that of AP in the clinical setting and imaging. TMI might be a supplementary indicator of the severity of AP.

Oncological imaging of the abdomen and pelvis: Spectrum of trends and advances

Advancements in medical imaging have brought about unprecedented changes in the assessment, management and post-treatment follow-up of cancer. Sonography, positron emission tomography, computed tomography and magnetic resonance imaging are the primary tools being developed for oncological imaging. Advancements in these modalities, the introduction of new imaging and treatment techniques, as well as recent management of tumors, have led to continuous changes in diagnosis and treatment. Herein, we discuss the wide spectrum of imaging trends and advances.