Differences in CT features of peritoneal carcinomatosis, sarcomatosis, and lymphomatosis: Retrospective analysis of 122 cases at a tertiary cancer institution

High-grade B-cell lymphoma, not otherwise specified, presenting as primary peritoneal lymphomatosis and successfully treated with dose-adjusted EPOCH-R

Peritoneal lymphomatosis (PL) is a rare lymphoma-associated condition defined as the dissemination of lymphoma cells in the peritoneum. An 82-year-old man presented with abdominal pain, heartburn, and high fever. Radiological findings, including positron emission tomography-computed tomography (PET-CT), and gastrointestinal fiberscopy, showed diffuse thickening of the peritoneum, omentum, and mesentery; however, no lymphadenopathy, hepatosplenomegaly, or gastrointestinal lesions were observed. Under suspicion of peritonitis carcinomatosa of unknown origin, exploratory laparoscopy was performed that revealed multiple white nodules and masses on the surfaces of the peritoneum, mesentery, and intestinal serosa. The histopathological and cytogenetic findings of the peritoneum revealed high-grade B-cell lymphoma, not otherwise specified, and a gain of MYC by fluorescence in-situ hybridization. The patient was treated with two cycles of R-CHOP therapy, followed by six cycles of dose-adjusted EPOCH-R therapy, and a complete metabolic response was confirmed by PET-CT. Since there are no specific radiological findings to confirm the diagnosis of PL, a histopathological diagnosis is usually required. Most PL exhibit an aggressive lymphoma phenotype and can be cured by appropriate chemotherapy. Therefore, early diagnosis and treatment are desirable.

A case of peritoneal Burkitt's lymphoma mimic of peritoneal tuberculosis

Peritoneal lymphomatosis is a rare presentation of lymphoma that can mimic peritoneal tuberculosis. The computed tomography findings in both conditions include omental caking, thickening, and nodularity. We report the case of a 41-year-old man who presented with intermittent abdominal pain and distension. Abdominal CT initially suggested peritoneal tuberculosis due to the thickening of the peritoneum and greater omentum with multiple nodules. However, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images showed diffuse metabolic activity increase in the thickened peritoneum, omentum, and mesentery. An omental biopsy was performed under ultrasonography guidance, and histopathological examination revealed a high-grade Burkitt lymphoma. It is crucial to distinguish peritoneal lymphomatosis from tuberculosis, as the prognosis and management of the two conditions are vastly different.

Is MDCT an accurate tool to differentiate between benign and malignant etiology in diffuse peritoneal disease?

PURPOSE

There is often considerable overlap of imaging findings in benign and malignant peritoneal diseases. We evaluated patients with diffuse peritoneal disease, to assess the diagnostic value of MDCT in predicting benign or malignant etiology in patients with unknown etiology, by analyzing the various patterns of involvement, particularly tuberculosis (TB) vs malignancy.

METHODS

One hundred and thirty-six patients with diffuse peritoneal disease who had abdominal CT and subsequently underwent omental biopsies were included in the study. Peritoneal, mesenteric and omental involvement by disease was evaluated on CT using specific parameters. The presence of lymphadenopathy, ascites, scalloping of organs, involvement of liver and spleen, were also compared between benign and malignant conditions using histopathology as the gold standard.

RESULTS

In 136 patients, 72 benign and 64 malignant pathologies were classified as per histopathology. Higher age (p < 0.001), increasing omental thickness (mean 25.2 mm, p = 0.004), omental caking (p < 0.001), > 10 mm mesenteric/peritoneal nodules (p < 0.03), visceral scalloping (p = 0.001), free ascites (p = 0.003), serosal involvement (p = 0.004) and bilateral pleural effusion (p = 0.02) were associated with malignant etiology. Mesenteric thickening/stranding (p = 0.02), mesenteric adenopathy (p < 0.001), necrotic nodes (p = 0.02), splenomegaly (p =  < 0.001) and higher attenuation (> 20HU) of ascitic fluid (p < 0.001) were associated with benign etiology. The presence of mesenteric thickening or stranding (p = 0.01), splenomegaly (p = 0.02), higher ascitic fluid attenuation > 20HU (p =  < 0.01), mesenteric adenopathy (p < 0.01), necrotic nodes (p = 0.03) favored tuberculosis. CT had diagnostic accuracy (79.3, 86.7%), sensitivity (79.2, 74.6%) and specificity (79.4, 97%) for observers 1 and 2, respectively (Kappa 0.713).

CONCLUSION

Contrast-enhanced MDCT has good sensitivity, specificity and accuracy in differentiating benign and malignant etiologies of diffuse peritoneal disease. Multiple common parameters can be used to differentiate between tuberculous peritonitis and peritoneal carcinomatosis.

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.

Non-Hodgkin's Lymphoma Presenting as Isolated Peritoneal Lymphomatosis: A Case Report and Literature Review

Peritoneal lymphomatosis is extremely rare and associated with poor prognosis. Most practitioners only pay more attention to peritoneal carcinomatosis. However, peritoneal lymphomatosis can be neglected and misdiagnosed. We report a teenager with 10 days of abdominal distension and pain accompanied by computed tomography scan suggesting diffuse thickening of the peritoneum and omentum and abdominopelvic effusion. Tuberculous peritonitis and peritoneal carcinomatosis were initially suspected. However, it was finally confirmed as non-Hodgkin’s B-cell lymphoma by omentum biopsies. He achieved complete remission after chemotherapy and autologous stem cell transplantation. But unfortunately, he suffered a relapse and died 10 months after diagnosis. Following a review of the literature, it can be concluded that the discovery of lymphomatosis in peritoneum is a rare finding. Lymphoma should be considered in the differential diagnosis of unexplained peritoneal thickening on computed tomography, and this case emphasizes the importance of early pathological diagnosis to make sure that the right treatment can be started opportunely.

Analysis of factors affecting the diagnostic yield of image-guided percutaneous core needle biopsy for peritoneal/omental lesions

PURPOSE

To evaluate the diagnostic yield, safety, and factors associated with the diagnostic yield of percutaneous core needle biopsy (PNB) for peritoneal/omental lesions.

METHODS

Consecutive 297 patients (67 men, 230 women; median age, 64 years [range 15-87]) who underwent a PNB for 311 peritoneal/omental lesions at a single center from April 2010 to March 2020 were evaluated retrospectively. The preprocedural CT findings, diagnostic yield, sensitivity, specificity, PPV, NPV, technical success rate, and adverse events were analyzed. Surgical or clinical diagnosis with follow-up was the diagnostic reference standard. Adverse events were evaluated using the Society of Interventional Radiology guidelines.

RESULTS

The median anteroposterior (AP) diameter and CT value of the target lesion were 24 mm (range 5-78) and 46 HU (range - 75 to 140), respectively. Ascites was interposed on the puncture route in 106 patients (34.1%). The technical success rate was 100%. The diagnostic yield, sensitivity, specificity, PPV, and NPV were 93.9%, 93.8%, 100%, 100%, and 20.8%, respectively. Minor complications were observed following five procedures (1.6%). The diagnostic yield was lower for fat-dominant lesions than for other lesions (82.6% vs. 95.8%, p = 0.002). The diagnostic PNB group had a greater AP diameter than did the non-diagnostic PNB group (27.3 ± 13.0 vs. 20.7 ± 8.4 mm, p = 0.037).

CONCLUSION

PNB for peritoneal/omental lesions provided a sufficiently high diagnostic yield and minimal adverse events. Lesions with a greater AP diameter and a higher density on CT would provide more diagnostic specimens from this technique.

Peritoneal Lymphomatosis: The Great Mimicker

Peritoneal lymphomatosis (PL) is defined as intraperitoneal dissemination of lymphoma. Although rare, it is associated with high-grade lymphomas and can be easily mistaken for peritoneal carcinomatosis (PC) on imaging, which is a common condition associated with gastrointestinal and gynecological malignancies. Both PL and PC share similar radiographic features, however, they differ considerably in terms of prognosis and management. We present a case of a 58-year-old male with abdominal distention and ascites, initially reported as having PC on imaging. A subsequent peritoneal biopsy revealed PL secondary to a low-grade follicular lymphoma. Since PL responds well to chemotherapy, its prompt diagnosis and differentiation from PC helps avoid unnecessary surgery.

Clinical, CT, and ultrasonographic features of canine and feline pleural and peritoneal carcinomatosis and sarcomatosis

Carcinomatosis and sarcomatosis describe the widespread dissemination of metastatic neoplastic cells throughout the body. Studies describing their clinical and imaging features in veterinary patients are limited. The objective of this retrospective, multicenter, cross-sectional study is to describe the clinical, ultrasonographic, and CT features of pleural and peritoneal carcinomatosis and sarcomatosis in dogs and cats to aid detection and differentiation of these lesions. Medical records and CT and ultrasonographic images were reviewed. Although a large degree of overlap was observed between the imaging features and clinical signs of canine and feline carcinomatosis and sarcomatosis, some distinguishing features were observed. Dogs were significantly more likely to present with abdominal pain compared to cats (P = .022), whereas cats more commonly presented with inappetence (P = .019). Dogs with sarcomatosis had a significantly heavier bodyweight than dogs with carcinomatosis (P = .005), largely due to a higher prevalence of splenic hemangiosarcoma in this patient cohort. Peritoneal effusion was more frequently observed in dogs with carcinomatosis compared to dogs with sarcomatosis (P = .021). Imaging and clinical features observed in this study may help to distinguish sarcomatosis and carcinomatosis lesions. Due to the large degree of overlap observed, cytological or histopathological analysis is recommended for definitive diagnosis.

Peritoneal lymphomatosis. A case report

Introduction

Involvement of the peritoneum occurs very rarely and is exceptional as an exclusive extranodal presentation of lymphomas. In most cases lymphomas associated with this rare entity are high-grade ones. PL secondary to high-grade nodal lymphoma is more frequent than primary peritoneal lymphoma, and there are only a few cases of the latter described in the literature.

Description of the case

We present the case of a patient with constitutional syndrome and imaging findings suggestive of peritoneal carcinomatosis who was finally diagnosed with a Diffuse Large B-cell Lymphoma (DLBCL) by an ultrasound-guided core needle biopsy (CNB) of peritoneum. The patient received one polychemotherapy cycle; however tumor lysis syndrome occurred with death of the patient in the following days.

This case tries to show the existence of a PL without other radiological findings of lymphoma, a fact that is very exceptionally described in the literature.

Discussion

The differential diagnosis between PL and others peritoneum diseases such as peritoneal carcinomatosis, malignant primary peritoneal mesotheliomas, tuberculous peritonitis, sarcomatosis, diffuse peritoneal leiomyomatosis or benign splenosis, constitutes a major problem in imaging techniques.

An exhaustive analysis of the radiological characteristics as well as a clinical-analytical context allows the differential diagnosis against peritoneal carcinomatosis and the rest of the entities previously referred although the final diagnosis will always be a biopsy.

Conclusion

PL usually manifests as an aggressive histological subtype of high-grade lymphomas leading to a rapid progression and deterioration of the patient. It is crucial for the radiologist and the clinician to be aware of this rare entity providing the earliest possible diagnosis and optimal treatment to prolong the patient's life.

High-grade B-cell lymphoma masquerading as peritoneal lymphomatosis

Peritoneal lymphomatosis represents a rare presentation of any type of non-Hodgkin's lymphoma, with relatively few cases reported in the literature. We present here the case of a 61-year-old man who originally presented with increased abdominal distention associated with shortness of breath and diaphoresis who was found to have evidence of peritoneal carcinomatosis on CT scan. Biopsy confirmed diffuse large B-cell lymphoma, and the working diagnosis was subsequently modified to peritoneal lymphomatosis. The patient was treated with dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (DA-EPOCH-R) therapy with initially good response. His course was complicated by tumour lysis syndrome. We review the limited literature discussing peritoneal lymphomatosis and discuss the importance of facilitating rapid and efficacious treatment.

[Extranodal abdominal lymphomas]

BACKGROUND

Extranodal manifestations occur in up to 40% of non-Hodgkin lymphomas. The prevalence of extranodal involvement has increased.

OBJECTIVES

A comprehensive overview on lymphoma involvement in the parenchymatous abdominal organs, the gastrointestinal tract, and the peritoneal cavity under due consideration of clinical implications is given.

MATERIALS AND METHODS

A selective literature search with analysis of dedicated original research articles and reviews was carried out. Clinical guidelines are discussed.

RESULTS

Extranodal abdominal lymphoma involvement usually occurs secondarily in advanced disease. Sites involved most frequently are the liver and the gastrointestinal tract. Extranodal abdominal lymphoma involvement is more common in the immunocompromised patient.

CONCLUSION

Imaging findings of extranodal abdominal lymphoma are variable. Lymphoma is an important differential diagnosis to be considered in unclear tumor diseases.

Peritoneal Lymphomatosis Masquerading as Pyoperitoneum in a Teenage Boy

A 16-year-old boy presented with 1 month of fever, abdominal pain, and distension. The ascitic tap drained pus-like fluid, and ultrasonography showed diffuse thickening of the omentum and mesentery with echogenic ascites. A diagnosis of pyoperitoneum due to peritoneal tuberculosis with secondary infection was suspected, and antitubercular therapy was started elsewhere, but there was no improvement. Computed tomography of the abdomen revealed enhancing soft-tissue thickening in the retroperitoneum, extending into the mesentery and encasing the superior and inferior mesenteric vessels. The ascitic fluid appearance deceptively resembled pus, but further analysis revealed atypical lymphocytes. Omental and bone marrow biopsies confirmed Burkitt lymphoma. Awareness of this rare presentation is imperative for making a correct diagnosis.

Ultrasonographic features of colonic B-cell lymphoma with mesenteric lymphomatosis in a cat

A 10-year-old male neutered Domestic Shorthair cat was referred for chronic inappetence, weight loss, and hematochezia and an abdominal mass. Abdominal ultrasonography revealed a heterogeneously hypoechoic transmural colonic mass, which extended beyond the serosa and into the adjacent mesentery. Cytology and clonality assays of fine needle aspirates of the mass and mesenteric nodules yielded a diagnosis of B-cell lymphoma. Colonic lymphoma with mesenteric involvement can have a similar appearance to carcinomatosis, therefore a definitive diagnosis requires sampling and further testing of the mesenteric lesions.

Metastatic Patterns of Solitary Fibrous Tumors: A Single-Institution Experience

OBJECTIVE

The objective of our study was to evaluate the metastatic patterns and imaging features of solitary fibrous tumors (SFTs).

MATERIALS AND METHODS

This retrospective study included 139 patients with pathologically proven SFT, 49 of whom developed metastases. Electronic medical records and all available images were reviewed to record the pattern and imaging appearances of metastatic disease, and comparisons of thoracic SFTs and extrathoracic SFTs were also performed. Associations of metastatic spread were studied using univariate and multivariate Cox regression analyses.

RESULTS

A total of 49 (35%) patients developed metastases at a median of 124 months (interquartile range [IQR], 66-195 months) after SFT diagnosis; 11 patients (8%) had metastases at presentation. Of these 49 patients, 40 patients died at a mean of 183 months after diagnosis. The associations with metastatic disease on univariate analysis were tumor size ≥ 10 cm (p = 0.01) and malignant pathology or mitotic count ≥ 4 per 10 high-power fields (HPF) (p < 0.001). Malignant pathology and a mitotic count of ≥ 4 per 10 HPF were also associated with metastatic disease on multivariate analysis (p = 0.01; hazard ratio, 0.22; 95% CI, 0.05-0.73). The most common sites of metastasis were the lungs (30/49, 61%) followed by the pleura (24/49, 49%) and then the liver (20/49, 41%), bones (20/49, 41%), and peritoneum (20/49, 41%). A significantly higher proportion of patients with extrathoracic SFT had metastatic disease (37/139, 27%) compared with those with thoracic SFT (12/139, 9%) (p = 0.003). The overall metastasis-free survival was a median of 117 months (IQR, 33-169 months) in patients with extrathoracic SFT and a median of 120 months (IQR, 82-169 months) in patients with thoracic SFT (p = 0.01).

CONCLUSION

A mitotic count of ≥ 4 per 10 HPF or malignant pathology was significantly associated with metastatic disease on both univariate and multivariate analyses. The sites of metastatic disease differed depending on the site of the primary SFT but were most commonly the lung and pleura. Patients with extrathoracic SFT were statistically more likely to develop metastatic disease than those with thoracic SFT.

The Role of ¹⁸F-FDG PET/CT in the Evaluation of Peritoneal Thickening of Undetermined Origin

The aim of this study was to assess the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for the differentiation of peritoneal thickening of undetermined origin. This retrospective study included 103 patients (44 men and 59 women, age 59.2 ± 14.8 years) who had undergone 18F-FDG PET/CT for the evaluation of peritoneal thickening of undetermined origin. All 18F-FDG PET/CT images were visually interpreted, and the maximal standardized uptake values (SUVmax) were measured. We compared the role of 18F-FDGPET/CT with that of CT alone in detecting peritoneal thickening of undetermined origin. We also compared the differences between malignant and tuberculous peritoneal thickening in PET/CT parameters and clinical characteristics. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy in detecting the primary cause of the peritoneal thickening were 76.2%, 78.9%, 94.1%, 42.9%, and 81.2%, respectively, for 18F-FDG PET/CT, and 58.3%, 84.2%, 94.2%, 31.4%, and 63.1%, respectively, for CT imaging. Malignant peritoneal thickening had significantly higher SUVmax than nontuberculous benign peritoneal thickening. However, tuberculous peritoneal thickening also had a high SUVmax. There were some factors that were significantly different between patients with tuberculous peritoneal thickening and those with malignant peritoneal thickening in our study; these included age, pattern of peritoneal thickening, and presence of ascites. 18F-FDG PET/CT is useful for detecting the underlying cause of peritoneal thickening. Special attention should be paid to peritoneal tuberculosis, which has a high SUVmax and may mimic malignant peritoneal thickening. Multiple PET/CT parameters which were different in patients with tuberculous and malignant causes could be taken into consideration to make the differential diagnosis.

Peritoneal lymphomatosis confused with peritoneal carcinomatosis due to the previous history of gastric cancer: a case report

Peritoneal lymphomatosis is a very rare disease of extranodal involvement of malignant lymphoma that is occasionally confounded with other peritoneal diseases. Herein, we reported the case of a 59-year-old woman who presented with massive ascites with prior history of stomach perforation during endoscopic procedure to treat early gastric cancer. Imaging studies showed massive ascites and tumor infiltration in the omentum and peritoneal wall. Initially, relapsed gastric cancer with peritoneal seeding was suspected based on the patient's history and imaging findings. However, final diagnosis was confirmed by ascites cytology as peritoneal lymphomatosis of diffuse large B-cell lymphoma unlike prior clinical information.

MDCT of extranodal mantle cell lymphoma: a single institute experience

OBJECTIVE

To study the pattern of extranodal and particularly gastrointestinal (GI) involvement of mantle cell lymphoma (MCL) on MDCT MATERIALS AND METHODS: In this IRB-approved, HIPAA compliant retrospective study, MDCT features of 78 patients (62 males and 16 females, mean age 57 years) with MCL including 28 patients at presentation were reviewed. Clinical and histopathological (blastoid vs. non-blastoid) data were noted from medical records.

RESULTS

Extranodal involvement was present in overall 51/78 patients on CT (65%), 18/28 (64%) patients at presentation. Spleen (21/78-27%) and bowel (19/78-24%) were the most common sites of extranodal involvement by MCL on imaging, followed by lungs (10/78-13%) and skin/subcutaneous tissue (9/78-12%). Bowel involvement was either in the form of endophytic polypoidal lesions (n = 11, mean size 3.1 cm), as focal mild bowel wall thickening (n = 5, mean thickness 1.4 cm), or as combination of the two (n = 3). Blastoid histology was present in 14/78 (24%) patients and was statistically associated with skin/subcutaneous involvement (p < 0.05; Fisher's exact t test). Median follow-up was 72 months during which 21 patients died with median survival of 48 months (26 months for blastoid histology vs. 47 months for non-blastoid histology). There was no statistical correlation between sites of involvement and survival.

CONCLUSIONS

MCL has a predilection for extranodal disease, predominantly involving the spleen, bowel, lungs, and subcutaneous tissue. GI involvement on CT is in the form of endoluminal polypoidal lesions and mild bowel wall thickening. Skin/subcutaneous involvement was statistically more common with blastoid histology in our study.