Multiple lesions of the spleen: differential diagnosis of cystic and solid lesions

Spleen anomalies and lesions in CT and MRI: essentials for radiologists and clinicians-a pictorial review

The precise evaluation of splenic lesions using cross-sectional imaging presents a complex challenge due to the overlapping imaging characteristics of most splenic diseases and the absence of specific symptoms, complicating the diagnosis process. This pictorial review highlights the essential elements that should be included in a radiology report to interpret cross-sectional imaging studies of splenic lesions. To augment the diagnostic accuracy, we propose the implementation of a stepwise algorithmic approach. This approach offers a comprehensive analysis of splenic anomalies and lesions, providing an invaluable tool for radiologists and clinicians.

Differentiating malignant from benign splenic lesions: a meta-analysis and pictorial review of imaging features

OBJECTIVES

Splenic lesions might exhibit overlapping imaging features, varying from benign entities like cysts and hemangiomas to malignancies such as lymphoma and angiosarcoma. This meta-analysis aims to delineate imaging characteristics that distinguish malignant from benign splenic lesions.

METHODS

Adhering to PRISMA guidelines, we searched PubMed, Scopus, and Web of Science for studies on imaging features differentiating malignant from benign splenic lesions. We extracted data on splenic pathology and imaging characteristics and assessed the methodological quality via QUADAS-2. Odds ratio meta-analyses were performed using STATA (Version 17.0, Stata Corp, College Station, TX).

RESULTS

Portal phase hypoenhancement, hypovascular enhancement pattern, diffusion restriction, and late phase hypoenhancement, with odds ratios above 10, highly indicate malignancy. Other features suggestive of malignancy include solid morphology, lymphadenopathy, presence of perisplenic fluid, arterial hypoenhancement, hypoechogenicity on ultrasound, splenomegaly, and presence of multiple lesions. In contrast, cystic morphology, hypervascular-washout and hypervascular-persistent pattern of enhancement, late phase hyperenhancement, anechogenicity on ultrasound, portal phase hyperenhancement, well-defined borders, and calcification are in favour of benign pathology.

CONCLUSION

The study underscores the critical role of contrast-enhanced and diffusion-weighted imaging in distinguishing malignant from benign splenic lesions, emphasizing the role of features like portal phase hypoenhancement and restricted diffusion in diagnosing malignancies. Additionally, the study emphasizes the value of contrast-enhanced ultrasound, which allows for the visualization of key contrast-enhancement patterns without the risk of ionizing radiation exposure.

Diagnostic approach to splenic lesions

BACKGROUND

 Splenic lesions are rare and mostly incidental findings on cross-sectional imaging. Most lesions are of benign nature and can be correctly identified based on imaging characteristics. Further, invasive evaluation is only necessary in cases of splenic lesions with uncertain or potentially malignant etiology.

METHOD

 While in most cases a correct diagnosis can be made from computed tomography (CT), (additional) magnetic resonance imaging (MRI) can aid in the identification of lesions. As these lesions are rare, only a few of the differential diagnoses are regularly diagnosed in the clinical routine.

RESULT AND CONCLUSION

 This review presents the differential diagnoses of splenic lesions, including imaging characteristics and a flowchart to determine the right diagnosis. In conjunction with laboratory results and clinical symptoms, histological workup is necessary only in a few cases, especially in incidental findings. In these cases, image-guided biopsies should be preferred over splenectomy, if possible.

KEY POINTS

  · Splenic lesions are rare and are usually incidental findings on abdominal imaging. · CT imaging and MRI imaging are the diagnostic tools of choice for the further workup of splenic lesions. · Based on their image morphological characteristics, a large number of splenic lesions can be assigned to one entity and do not need histological analysis.

CITATION FORMAT

· Krähling H, Seidensticker M, Heindel WL et al. Diagnostic approach to splenic lesions. Fortschr Röntgenstr 2024; 196: 573 - 581.

A Glimpse into the Role and Effectiveness of Splenectomy for Isolated Metachronous Spleen Metastasis of Colorectal Cancer Origin: Long-Term Survivals Can Be Achieved

Background: Many papers exploring the role of resectioning metastases in colorectal cancer (CRC) have focused mainly on liver and lung sites, showing improved survival compared with non-resectional therapies. However, data about exceptional metastatic sites such as splenic metastases (SMs) are scarce. This paper aims to assess the role and effectiveness of splenectomy in the case of isolated metachronous SM of CRC origin. Methods: The patients' data were extracted after a comprehensive literature search through public databases for articles reporting patients with splenectomies for isolated metachronous SM of CRC origin. Potential predictors of survival were explored, along with demographic, diagnostic, pathology, and treatment data for each patient. Results: A total of 83 patients with splenectomies for isolated metachronous SM of CRC origin were identified. The primary CRC was at an advanced stage (Duke's C-70.3%) and on the left colon (45.5%) for most patients, while the median interval between CRC resection and SM was 24 months. The median overall survival after splenectomy was 84 months, and patients younger than 62 years presented statistically significantly worse overall survival rates than those ≥62 years old (p = 0.011). There was no significant impact on the long-term outcomes for factors including primary tumor location or adjuvant chemotherapy (p values ≥ 0.070, ns). Laparoscopic splenectomy was increasingly used in the last 20 years from 2002 (33.3% vs. 0%, p < 0.001). Conclusions: Splenectomy is the optimal treatment for patients with isolated metachronous SM of CRC, with the laparoscopic approach being increasingly used and having the potential to become a standard of care. Encouraging long-term survival rates were reported in the context of a multidisciplinary approach. Younger ages are associated with worse survival. Perioperative chemotherapy in the context of a patient diagnosed with SM of CRC origin appears to be a reasonable option, although the present study failed to show any significant impact on long-term survival.

Splenic Embolism in Infective Endocarditis: A Systematic Review of the Literature with an Emphasis on Radiological and Histopathological Diagnoses

Infective endocarditis (IE) is characterised by fever, heart murmurs, and emboli. Splenic emboli are frequent in left-sided IE. A systematic review of the literature published on splenic embolism (SE) between 2000 and 2023 was conducted. Search strategies in electronic databases identified 2751 studies published between 1 January 2000 and 4 October 2023, of which 29 were finally included. The results showed that the imaging tests predominantly used to detect embolisms were computed tomography (CT), magnetic resonance imaging, positron emission tomography (PET)/CT, single-photon emission computed tomography/CT, ultrasound, and contrast-enhanced ultrasound. More recent studies typically used 18F-FDG PET-CT. The proportion of SE ranged from 1.4% to 71.7%. Only seven studies performed systematic conventional CT screening for intra-abdominal emboli, and the weighted mean frequency of SE was 22% (range: 8-34.8%). 18F-FDG PET-CT was performed systematically in seven studies, and splenic uptake was found in a weighted mean of 4.5%. There was a lack of uniformity in the published literature regarding the frequency and management of splenic embolisation. CT scans were the most frequently used method, until recently, when 18F-FDG PET-CT scans began to predominate. More data are necessary regarding the frequency of SE, especially focusing on their impact on IE management and prognosis.

Point-of-care ultrasound for tuberculosis and HIV-revisiting the focused assessment with sonography for HIV-associated tuberculosis (FASH) protocol and its differential diagnoses

BACKGROUND

The 'Focused assessment with sonography for HIV-associated tuberculosis' (FASH) protocol has been applied and researched for over a decade in HIV-infected patients with suspected extra-pulmonary tuberculosis. Interpretation of target FASH features may be challenging as they can also indicate alternative opportunistic diseases.

OBJECTIVES

The primary aim of the review was summarizing the accumulated evidence on the diagnostic accuracy of the FASH protocol including description of diagnoses of target FASH features.

SOURCES

Literature was searched using PubMed, Google Scholar, and publications referencing the original FASH publications; data from identified studies were compiled with data from studies identified by a preceding Cochrane review. A meta-analysis was performed based on a generalized linearized mixed model. Data on differential diagnoses were compiled by literature review and retrospective evaluation of clinical data.

CONTENT

We identified ten studies; abdominal target FASH features were most studied. Sensitivity and specificity estimates were 39% (95% CI 25-54) and 89% (95% CI 83-96) for enlarged lymph nodes (ten studies), and 30% (95% CI 16-45%) and 93% (95% CI 89-98%) for hypoechoic spleen lesions (eight studies). In people living with HIV differential diagnoses of target FASH features are multiple and primarily include other opportunistic infections and malignancies such as non-tuberculous mycobacterial infection, bacillary angiomatosis, hepato-splenic brucellosis, meliodiosis, visceral leishmaniasis, invasive fungal infections, and lymphoma as well as Kaposi sarcoma. Ultrasound-guided diagnostic sampling may assist obtention of a definitive diagnosis.

IMPLICATIONS

On the basis of current evidence, although limited by methodology, and personal experience, we recommend basic ultrasound training, including the FASH protocol and ultrasound-guided diagnostic interventions, for all healthcare providers working with people living with HIV in resource-limited settings.

Percutaneous ultrasound-guided coaxial core needle biopsy for the diagnosis of multiple splenic lesions: A case report

BACKGROUND

The overlap of imaging manifestations among distinct splenic lesions gives rise to a diagnostic dilemma. Consequently, a definitive diagnosis primarily relies on histological results. The ultrasound (US)-guided coaxial core needle biopsy (CNB) not only procures sufficient tissue to help clarify the diagnosis, but reduces the incidence of puncture-related complications.

CASE SUMMARY

A 41-year-old female, with a history of pulmonary tuberculosis, was admitted to our hospital with multiple indeterminate splenic lesions. Gray-scale ultrasonography demonstrated splenomegaly with numerous well-defined hypoechoic masses. Abdominal contrast-enhanced computed tomography (CT) showed an enlarged spleen with multiple irregular-shaped, peripherally enhancing, hypodense lesions. Positron emission CT revealed numerous abnormal hyperglycemia foci. These imaging findings strongly indicated the possibility of infectious disease as the primary concern, with neoplastic lesions requiring exclusion. To obtain the precise pathological diagnosis, the US-guided coaxial CNB of the spleen was carried out. The patient did not express any discomfort during the procedure.

CONCLUSION

Percutaneous US-guided coaxial CNB is an excellent and safe option for obtaining precise splenic tissue samples, as it significantly enhances sample yield for exact pathological analysis with minimum trauma to the spleen parenchyma and surrounding tissue.

Case report: Aseptic splenic abscesses in childhood-onset systemic lupus erythematosus

Background

Systemic lupus erythematosus (SLE) can involve any organ system and cause a wide range of manifestations. Noninfectious inflammatory lesions termed aseptic abscesses have been reported in some autoimmune and autoinflammatory conditions but not in childhood-onset SLE. In this report, we highlight the unusual finding of occult splenic abscesses in two children diagnosed with SLE who had no evidence of concomitant infection.

Case presentation

An 8-year-old and an 11-year-old were admitted separately to the hospital with fever for 7 and 14 days, respectively. In the younger child, a generalized rash preceded the fever. Both had been well, with no significant past medical history prior to the onset of the illness. In both girls, abdominal ultrasonography showed multiple small hypoechoic lesions suggestive of abscesses scattered throughout the spleen. Their C-reactive protein and blood cultures were negative, and symptoms persisted despite intravenous antibiotics. Fulfilling the clinical and immunologic criteria for diagnosis, both were ultimately diagnosed with childhood-onset SLE. Rapid recovery of symptoms and complete resolution of the abscesses ensued with corticosteroids and immunosuppressive therapy.

Conclusions

These two cases suggest that aseptic splenic abscesses may occur in childhood-onset SLE. Autoimmune conditions such as SLE should be included in the differential diagnosis of children with occult splenic abscesses.

Unusual Rapid Growth of Primary Splenic Diffuse Large B-Cell Lymphoma with Extensive Necrosis

The primary splenic lymphoma is extremely uncommon with an incidence rate of <1% of all the lymphomas under the strict criteria for diagnosis expounded by Das Gupta et al. Clinical presentations of nonspecific symptoms are weight loss, weakness, fever, and left upper quadrant pain or discomfort due to enlarged spleen. Abdominal ultrasound and CT are the most widely used imaging modality for the assessment of lymphoma. The imaged features of splenic lymphoma are nonspecific; typical lymphoma presents as a diffusely enlarged spleen. The abdominal CT scan in our case showed a large cystic splenic mass measuring 14 cm without enhancement after contrast medium. Lymphoma is often described as an aggressive tumor because its rapid doubling time can quickly increase the size of a tumor. In our case, the tumor grew to more than 100 times its original size in 4 months. So, we present this unusual rapid growth of primary splenic lymphoma.

Imaging patterns in non-traumatic spleen lesions in adults-a review

The spleen is a complex organ involved in multiple physiological processes in the human body. Elective splenectomy is an uncommon operation, and the precise characterization of the lesion should be achieved to determine the risks and benefits of this operation accurately. Given the significant role of the spleen in homeostasis and the potential risks of the surgery itself and following sequelae such as infection susceptibility, accurate recognition, and classification of splenic lesions is required before surgery. This review provides an overview of malignant (e.g., lymphoma, angiosarcoma) and benign (e.g., cysts, hemangioma, hamartoma) splenic lesions that may warrant an elective splenectomy. Images from a cohort of adult patients undergoing isolated splenectomy for non-traumatic indications in a single center are provided. This review highlights the considerable overlap in imaging patterns between splenic lesions, splenic lesions masquerading as lesions in other organs, increased detection of asymptomatic splenic incidentalomas due to improvements in imaging modalities. This review also provides clinical correlations for each lesion, providing additional information to help clinicians differentiate between lesions and accurately identify diseases amenable to surgical management.

Clostridium perfringens splenic abscess treated with percutaneous drainage and antibiotic therapy: a case report

INTRODUCTION

Splenic abscesses are a rare medical entity with high mortality, with Clostridium perfringens being an exceptional pathogen. We present the first case describing an abscess of the spleen in a patient undergoing treatment with adalimumab, an anti-tumour necrosis factor commonly used in inflammatory bowel diseases.

PATIENT

We describe the case of a 73-year-old woman, treated with adalimumab therapy, who was found to have a splenic abscess, caused by C. perfringens.

RESULT

After antibiotic treatment and percutaneous drainage, the patient recovered both clinically and radiographically.

DISCUSSION

We reviewed literature about C. perfringens splenic abscesses. In all cases identified, a splenectomy was performed. This is the first case description of splenic abscess caused by C. perfringens where a percutaneous drainage was performed, leading to complete recovery in our patient. This seems to indicate that a splenectomy is not necessary in all C. perfringens splenic abscesses.

Algorithmic Approach to the Splenic Lesion Based on Radiologic-Pathologic Correlation

Splenic lesions are commonly discovered incidentally at imaging, without clinical signs or symptoms that may aid in diagnosis. As such, the differential diagnosis and subsequent management are based primarily on imaging characteristics. Much has been written about the myriad pathologic conditions that can occur in the spleen; however, there is little guidance on the approach to an incidental splenic mass. Applying an approach frequently used in imaging to the splenic mass-based on the number and consistency of lesions and refined by supplementary imaging features-allows formulation of a useful differential diagnosis. Solitary cystic masses include true cysts, pseudocysts, and parasitic cysts. When multiple cystic lesions are present, the differential diagnosis expands to include infectious lesions (abscess or microabscesses) and lymphangioma (a benign cystic neoplasm). Hemangioma is the most common solitary solid mass, although other vascular lesions (hamartoma, sclerosing angiomatoid nodular transformation) and nonvascular lesions (inflammatory pseudotumor, lymphoma) manifest as solitary and solid. When multiple solid masses are present, diffuse inflammatory disease (sarcoidosis), littoral cell angioma, and lymphoma should be considered. Malignancies, such as angiosarcoma or metastasis, can manifest as solitary or multiple and solid or cystic masses but are typically associated with symptoms or widespread primary malignancy. Careful assessment of the multimodality imaging characteristics of splenic lesions based on this approach aids the radiologist faced with the incidental splenic lesion. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Ultrasonographic atlas of splenic lesions

Ultrasonography (US) is widely used for abdominal imaging. Its noninvasiveness, extensive range of application, and low cost make US a useful and valuable tool for the detection, diagnosis, and follow-up of splenic abnormalities. Concomitantly with the increasing frequency of imaging, more splenic lesions are being discovered and the requirements for the differential diagnosis are rising. In this pictorial essay, we introduce the representative US findings of many different splenic lesions, including normal sonographic findings, normal variants and congenital anomalies, infectious conditions, benign and malignant neoplasms, and non-neoplastic lesions. Knowledge of the US features of various splenic lesions will help narrow the differential diagnosis and guide clinical decision-making.

Splenic infarction secondary to COVID-19 complicated by Clostridium Paraputrificum infection

A 58-year-old woman with COVID-19 presented with an acute abdomen. Her spleen was found to be infarcted with a large fluid and gas collection. Treatment included broad-spectrum antibiotics and CT-guided drainage. Definitive treatment was splenectomy. We postulate that COVID-19 related splenic infarction created ideal conditions for Clostridium paraputrificum to cause a splenic abscess.

Spleen angiosarcoma: a world review

Introduction: Spleen angiosarcoma (SA) is a rare malignant neoplasm that arises from the splenic vascular endothelium, with only around 300 cases reported to date. Due to a limited number of reported cases, there is a paucity of data and a lack of understanding of its presentation, diagnosis, and management. In this study, we aim to provide a comprehensive review of SA.Areas covered: On 27 February 2021, a literature search was done in PubMed and Embase database. The search yielded 122 articles involving 205 patients. The focus was on patient demographics, risk factors, clinical presentations, investigation results, preliminary diagnoses, therapies provided, and patient outcomes. These factors were analyzed to identify possible risk factors, diagnostic modalities, and therapeutic principles that were not mentioned before.Expert opinion: The clinical presentation or investigation results of patients with SA are often nonspecific. Hence, they may not be sufficient to clinch the diagnosis of SA if used alone. The authors recommend a triple assessment of clinical examination, imaging findings, and pathology to diagnose SA with high accuracy. Splenectomy should be the mainstay of management, with chemotherapy and radiotherapy considered as adjuncts, especially in the presence of metastases.

CT and MRI Findings of Focal Splenic Lesions and Ascites in Generalized Lymphatic Anomaly, Kaposiform Lymphangiomatosis, and Gorham-Stout Disease

Objectives:

This study aimed to evaluate the CT and MRI findings of focal splenic lesions and ascites in generalized lymphatic anomaly (GLA), kaposiform lymphangiomatosis (KLA), and Gorham-Stout disease (GSD).

Material and Methods:

Twenty-three patients (10 with GLA, 5 with KLA, and 8 with GSD) who underwent abdominal CT and/or MRI before treatment were included in this study, and their imaging findings were retrospectively evaluated.

Results:

Focal splenic lesions were observed in nine patients; these lesions were observed frequently in GLA (n = 5; 50%) or KLA (n = 3; 60%) compared with GSD (n = 1; 13%); however, no significant differences were found between the three groups (P = 0.190). On CT images among eight patients (4 with GLA, 3 with KLA, and 1 with GSD) with focal splenic lesions who underwent CT, the number of focal splenic lesions per patient ranged from 2 to 189 (mean, 42) and the maximum diameter of focal splenic lesions ranged from 2 to 39 mm (mean, 8 mm), while more than 30 focal splenic lesions per patient were observed in 2 (50%) GLA and focal splenic lesions with maximum diameters of ≥10 mm were observed in 4 (100%) GLA but not in KLA or GSD. Ascites was observed in five patients; significant differences were observed among KLA (n = 4; 80%), GLA (n = 1; 10%), and GSD (n = 0; 0%) (P < 0.01). Ascites was significantly more frequent in KLA than in GSD (P < 0.05).

Conclusion:

More than 30 focal splenic lesions per patient and/or focal splenic lesions with maximum diameters of ≥10 mm were observed only in GLA. Focal splenic lesions tended to be less frequent in GSD, whereas ascites tended to be frequent in KLA.

Imaging findings of benign and malignant pediatric splenic lesions

Splenic lesions in children have a wide histological spectrum. The majority of pediatric splenic lesions are benign and detected incidentally, and the most common benign lesions are cysts, followed by hemangiomas and lymphatic malformations. Most of the splenic malignancies in children are secondary to leukemia or lymphoma. The purpose of this article is to describe the ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) features of benign and malignant splenic lesions in the pediatric age group.

Focal splenic lesions: Imaging spectrum of diseases on CT, MRI and PET/CT

The spleen can be affected by a variety of diseases. Some of them are readily identified as variations of normal or benign diseases on imaging. However, for a substantial number of focal splenic abnormalities, the diagnosis can be difficult so that histopathologic analysis may be required for a definite diagnosis. In this review, the typical splenic abnormalities that can be diagnosed with imaging with a high degree of confidence are illustrated. The complementary role of computed tomography (CT), magnetic resonance imaging and positron emission tomography/CT that helps make a diagnostic approach is discussed. Finally, current applications and future trends of radiomics and artificial intelligence for the diagnosis of splenic diseases are addressed.

Value of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Focal Splenic Lesions

Purpose

To identify and validate contrast-enhanced ultrasound (CEUS) features for differentiating malignant from benign splenic lesions.

Patients and Methods

Splenic lesions in 123 patients who underwent conventional ultrasound (B-mode US) and CEUS were included in this study. Two radiologists evaluated the sonograms of B-mode and CEUS. Statistical analysis was performed to identify significant imaging predictors for splenic malignant lesions. Two other radiologists independently reviewed B-mode and CEUS sonograms and diagnosed the lesions based on proposed criteria as 1) benign, 2) probably benign, 3) probably malignant or 4) malignant. The diagnostic efficiency between B-mode US and CEUS was compared.

Results

Common imaging findings of malignant lesions included hypoechoic, ill-defined margin, absence of cystic/necrotic portion, presence of splenomegaly on B-mode US, and hypoenhancement, rapid washout and presence of intralesional vessels on CEUS (P < 0.05). Among them, three independent features were identified using multivariate logistic regression analysis: hypoechoic pattern, hypoenhancement pattern and intralesional vessels. When three of these findings were combined as a predictor for splenic malignant lesions, 22 (55.0%) of 40 malignant splenic lesions were identified with a specificity of 100%. The diagnostic performance of two readers using receiver operating characteristic curve analysis was 0.622 and 0.533, respectively, for B-mode US, which was significantly improved to 0.908 and 0.906 for CEUS (P < 0.001). The degree of other diagnostic efficiency and inter-reader agreement also increased with CEUS compared to B-mode US.

Conclusion

CEUS may provide more useful information than B-mode US and improve the diagnosis efficiency for distinguishing malignant from benign splenic lesions.

Revisiting the Spleen—An Imaging Review of the Common and Uncommon Splenic Pathology

The spleen is the largest lymphatic organ and is responsible for both hematological and immunological functions. Several common etiologies such as trauma, developmental variants, infectious/inflammatory conditions, and benign and malignant lesions can occur in the spleen. The role of imaging modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in diagnosing these conditions continues to evolve. The main objective of this review article is to illustrate the role of imaging in identifying the common and uncommon pathology of the spleen.

Iron-containing pathologies of the spleen: magnetic resonance imaging features with pathologic correlation

Systemic and non-systemic pathologies that involve iron deposition within the spleen have characteristic features on MRI due to the susceptibility properties of deposited iron, or hemosiderin. These lesions will have signal loss on longer echo sequences due to the T2* effect when evaluated with dual-echo gradient-echo sequences. The pathophysiology of systemic and localized iron sequestration disease processes can elucidate an underlying diagnosis based on these imaging features in conjunction with clinical information.

Rapidly Progressing Aseptic Abscesses in a Patient with Ulcerative Colitis

Aseptic abscesses (AAs) are extraintestinal manifestations of inflammatory bowel disease (IBD). IBD-associated AAs are rare in Japan. We treated a 45-year-old man with ulcerative colitis (UC)-associated AAs. During remission, multiple progressive abscesses were detected in the spleen; he underwent splenectomy because an infectious disease was suspected. Although his condition improved temporarily after splenectomy, a large liver abscess was noted, and a diagnosis of UC-associated AAs was made. Granulocytapheresis (GCAP) and infliximab (IFX) administration resolved the abscess. This is the first reported case of UC-associated AAs in a Japanese patient treated by splenectomy, GCAP, and IFX.

Efficacy and tolerability of folate-aminopterin therapy in a rat focal model of multiple sclerosis

BACKGROUND

Activated macrophages in the experimental model of multiple sclerosis (MS) express folate receptor-β (FR-β), representing a promising target for the treatment of MS. Here, we both evaluated the efficacy of a novel folate-aminopterin construct (EC2319) in a rat focal model of multiple sclerosis (MS) and investigated the utility of ⁶⁸Ga-labeled 1,4,7-triazacyclononane-1,4,7-triacetic acid-conjugated folate (⁶⁸Ga-FOL) for assessing inflammatory lesions. In addition, we investigated whether FR-β is expressed in the brain of patients with MS.

METHODS

Focal delayed-type hypersensitivity experimental autoimmune encephalomyelitis (fDTH-EAE) was induced in 40 Lewis rats; 20 healthy Lewis rats were used as controls. Rats were divided into six groups according to the duration of disease (control, acute, or chronic) and intervention (vehicle versus EC2319). ⁶⁸Ga-FOL analyses, histology, and immunofluorescence of the brain were performed to evaluate the efficacy of subcutaneously administered EC2319 on lesion development. Immunofluorescence was used to assess FR-β expression in postmortem brain samples from 5 patients with MS and 5 healthy controls.

RESULTS

Immunofluorescence and histological analyses revealed significant reductions in FR-β expression (P < 0.05) and lesion size (P < 0.01), as well as improved inducible nitric oxide synthase/mannose receptor C type 1 ratios (P < 0.01) in macrophages and microglia during the chronic but not acute phase of fDTH-EAE in EC2319-treated rats. The uptake of IV-injected ⁶⁸Ga-FOL in the brain was low and did not differ between the groups, but the in vitro binding of ⁶⁸Ga-FOL was significantly lower in EC2319-treated rats (P < 0.01). FR-β positivity was observed in chronically active lesions and in normal-appearing white matter in MS brain samples.

CONCLUSIONS

EC2319 was well tolerated and attenuated inflammation and lesion development in a rat model of a chronic progressive form of MS. Human MS patients have FR-β-positive cells in chronically active plaques, which suggests that these results may have translational relevance.

Evaluation of cross-sectional imaging features that aid in the differentiation of benign and malignant splenic lesions

PURPOSE

This study aimed to investigate the role of cross-sectional imaging in differentiating between benign and malignant splenic lesions based on various imaging features.

METHODS

Database of imaging reports from January 2015 to December 2017 were searched dedicatedly for "spleen" or "splenic" terms to identify patients with splenic lesions found either on CT or MRI. The study cohort consisted of patients who had available histological reports or had follow-up imaging for a minimum of one year. Patients were categorized into the benign subcohort if they did not have a history of extra-splenic malignancy, and had a splenic lesion(s) falling into one of these categories: benign histopathology on biopsy, stable size and enhancement, or decreased size on follow-up imaging. Those who had malignant histopathology on biopsy were included in the malignant subcohort. Various morphologic features and enhancement patterns of these lesions were carefully reviewed by two radiologists who were blinded to the final histopathologic diagnosis.

RESULTS

We identified 161 patients (54 % males, mean age ± SD = 59.7 ± 15.4) including 124 (77 %) in the benign and 37 (23 %) in the malignant subcohort. Benign lesions were more likely to be cystic (21.7 % vs 2.7 %, p < 0.001), homogenous (59.7 % vs. 29.7 %, p = 0.001) and to demonstrate well-defined borders (69.3 % vs. 29.7 % p= <0.001). Malignant lesions had significantly larger diameter (median size: 15 vs 11 mm, p = 0.03). Restricted diffusion was not seen in any of the benign lesions; however, 50 % of malignant lesions demonstrated restricted diffusion (p = 0.003). Features such as lesion distribution, presence of calcification, splenomegaly and number of lesions were not significantly different between benign and malignant lesions.

CONCLUSION

Smaller lesion diameter, well-defined border and homogeneity favor benign nature of splenic lesions while restricted diffusion should raise suspicion for malignancy.

Splenic Infarct Secondary to High Altitude Exposure in Sickle Cell Trait Patients: A Case Series

The sickle cell trait is considered a benign entity that generally does not show clinical manifestations. However, some complications have been described under certain conditions, such as a decrease in oxygen level, dehydration, and strenuous physical efforts. Among them, splenic infarct is a rare complication that presents as left upper abdominal pain in a situation of stress such as high altitude exposure. We present two cases of splenic infarcts in patients with undiagnosed sickle cell trait who showed to our institution with severe abdominal pain after coming from high altitude cities.

Sarcoidosis with Splenic Involvement Diagnosed with Endoscopic Ultrasound-guided Fine-needle Aspiration

Splenic sarcoidosis is often diagnosed by splenectomy or an ultrasound-guided splenic biopsy. However, splenectomy is invasive and costly, and a percutaneous biopsy is sometimes difficult. We herein report a case of splenic sarcoidosis diagnosed with endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). A 71-year-old man was referred to our hospital for abnormal shadows on a chest roentgenogram. Computed tomography showed multiple lesions in the spleen and pulmonary consolidations. Bronchoscopy revealed no definitive diagnosis. We therefore performed EUS-FNA for a splenic lesion that led to the diagnosis. This case suggests that EUS-FNA is useful in confirming the diagnosis of sarcoidosis with suspected splenic lesions.

Detection of spleen abscesses facilitates diagnosis of melioidosis in Malaysian children

OBJECTIVES

Melioidosis is associated with extremely high case fatality ratios. The aim of this study was to determine whether detection of abdominal visceral abscesses can facilitate diagnosis of melioidosis in children.

METHODS

We conducted a retrospective analysis of all children who had liver and/or spleen abscesses on abdominal ultrasonography admitted to Bintulu Hospital in Sarawak, Malaysia, from January 2014 until December 2018.

RESULTS

Fifty-three children had liver and/or spleen abscesses. Spleen abscesses were present in 48 (91%) cases; liver abscesses in 15 (28%). Melioidosis was confirmed by culture in 9 (17%) children; small occult splenic abscesses were present in all cases. In 78% of these cases, the lesions were detected before any positive culture (or serology) results were available. Four (8%) children had bacteriologically-confirmed tuberculosis. Two (4%) had Staphylococcus aureus infection. Of the remaining 38 (72%) culture-negative cases, 36 (95%) had clinical and imaging characteristics similar to that of children with culture-confirmed melioidosis and improved with empirical melioidosis antibiotic therapy.

CONCLUSIONS

A large number of children in Bintulu Hospital in Sarawak, Malaysia, were found to have spleen abscesses. Melioidosis was the most common etiology identified in these children. Abdominal ultrasonography is extremely useful in facilitating the diagnosis of pediatric melioidosis.

Role of CT in Differentiating Malignant Focal Splenic Lesions

Objective

The purpose of this study was to asses the CT findings and clinical features differentiating malignant from benign focal splenic lesions.

Materials and Methods

Among 673 patients with splenectomy, we included 114 patients with pathologically confirmed focal splenic lesions (malignant = 66, benign = 48). Two radiologists retrospectively assessed CT findings including: size, number, solid component, margin, wall, calcification, contrast-enhancement, lymph node (LN) enlargement and possible malignancy. We assessed clinical features including age, sex, underlying malignancy, fever, and leukocytosis. Multivariate logistic regression analysis was performed to identify significant predictors of malignant lesion. We used receiver operating curve analysis for determination of diagnostic performance.

Results

Common findings of malignant lesions include enhanced, mainly solid, ill-defined margin, absence of splenomegaly, absence of the wall, absence of calcification, LN enlargement, and presence of underlying malignancy (p < 0.05). Among them, mainly solid features (odds ratio [OR], 39.098, p = 0.007), LN enlargement (OR, 6.326, p = 0.005), and presence of underlying malignancy (OR, 8.615, p = 0.001) were significant predictors of malignancy. The mean size of benign splenic lesions (5.8 ± 3.3 cm) was larger than that of malignant splenic lesions (4.0 ± 3.4 cm). Diagnostic performance of CT findings by two reviewers using receiver operating characteristic curve analysis for differentiation of malignant lesions was 0.856 and 0.893, respectively.

Conclusion

Solid nature of the splenic mass on CT images, LN enlargement, and presence of underlying malignancy are significant predictors of malignant splenic lesion.

Extranodal lymphomas of abdomen and pelvis: imaging findings and differential diagnosis

A wide spectrum of extranodal lymphomas in the abdomen and pelvis is commonly encountered by imaging. Diagnosing these lesions generally requires a multimodality approach. This review highlights imaging appearances of extranodal lymphomas in the abdomen and pelvis with emphasis on computed tomography, magnetic resonance imaging, and positron emission tomography-computed tomography along with the relevant differential diagnosis.

Splenic abscess owing to cancer at the splenic flexure: A case report and comprehensive review

BACKGROUND

The cancer of the splenic flexure of the colon is a rare medical entity with severe morbidity because of its insidious onset.

METHODS

We present the case of a 59-year-old male patient with dull left upper quadrant pain, leukocytosis, and anemia. A splenic abscess described as an air-fluid level with splenocolic fistula was found on CT scan imaging. Surgery was done for splenic pus drainage. He was again admitted 2 months later for intestinal obstruction.

RESULTS

An exploratory laparotomy showed multiple hard, gray liver nodules as well as a hard mass in the small bowel. Owing to extensive adhesions and a late stage of cancer involvement, the splenic flexure tumor was not resected. A loop transverse colostomy was done and a Coloplast Colostomy bag placed. We also reviewed the literature-linking colon cancer and splenic abscess with specific attention to the carcinoma of the splenic flexure. As the latter invades through the spleen matter, there is the creation of a splenocolic fistula, which allows the migration of normal gut flora into the spleen. This leads to the formation of the splenic abscess.

CONCLUSION

This is the 13 case report pertaining to invading colonic cancer causing a splenic abscess. Although the treatment for splenic abscesses is shifting from splenectomy to image-guided percutaneous pus drainage, the few reported cases make the proper management of such complication still unclear.

Imaging of the spleen: what the clinician needs to know

The spleen is considered 'the forgotten organ' among radiologists and clinicians, although it is well visualised on abdominal computed tomography and magnetic resonance imaging. Moreover, the spleen is commonly involved in a wide range of pathologic disorders. These include congenital anomalies, infectious and inflammatory diseases, vascular disorders, benign and malignant tumours, and systemic disorders. In this review, we focus on the key imaging findings of the normal spleen, its variants, as well as relevant congenital and acquired abnormalities. It is of utmost importance to recognise and correctly interpret the variable spectrum of abnormalities that may involve the spleen, in order to avoid unnecessary invasive procedures and to guide adequate treatment.

A Splenic Epithelial Cyst: Increased Size, Exacerbation of Symptoms, and Elevated Levels of Serum Carcinogenic Antigen 19-9 after 6-year Follow-up

A 58-year-old man, who had presented with a large cyst between the pancreatic tail and splenic hilum 6 years previously, was referred to our hospital with exacerbation of abdominal distention. Computed tomography revealed a well-demarcated, unilocular cyst, with a beak sign for the pancreas, without wall thickening or nodules suggestive of a non-neoplastic cyst. Compared with 6 years previously, the cyst had increased in size from 14.7 cm to 19.5 cm, and the serum carcinogenic antigen 19-9 level had increased from 635 U/mL to 1,918 U/mL. To prevent spontaneous rupture, laparotomy was performed, and the cyst was pathologically diagnosed as a splenic epithelial cyst.

Multiple Targetoid Lesions in the Spleen

Chronic lymphocytic leukemia (CLL) is the most prevalent hematologic malignancy of adults in the western hemisphere. Involvement of the spleen is not uncommon, often presenting as diffuse enlargement due to infiltration of neoplastic cells. A case is presented of an 81-year-old woman with a past medical history of CLL who was incidentally found to have multiple, focal splenic infiltrates on sonography. The patient had a normal sized spleen, which is a less common occurrence with splenic invasion by CLL. As current CLL guidelines discourage imaging but rely on evidence of organ involvement, this finding was critical in staging the patient properly. The sonographic appearance of this rare condition is described, and the advantages of sonography in its evaluation are discussed.

A rare case of a splenic hamartoma in a patient with a huge palpable abdominal mass: a case report

Introduction

Splenic hamartoma is a primary benign tumor of the spleen, which is often found incidentally. Splenic hamartomas are very rare, with approximately 150 cases documented in the literature to date. They represent benign vascular proliferation. Histological findings consist of disorganized stroma and vascular channels of varying width, with or without lymphoid follicles.

Case presentation

We present the case of a 39-year-old Greek woman, with no significant medical history, who was diagnosed incidentally with an enormous splenic hamartoma on computed tomography, finally confirmed by surgery and histopathology. Hamartomas are benign lesions, and it is important to differentiate them from malignancy.

Conclusion

Hamartoma represents a rare vascular entity characterized by a cluster of differentiation 8-positive immunophenotype. It is usually asymptomatic but large hamartomas may present with symptoms such as hemopoetic disorders, which resolve after splenectomy. It is important for radiologists to be able to differentiate splenic hamartoma from malignant entities.

Image-guided percutaneous splenic biopsy and drainage

Percutaneous splenic biopsy and drainage are relatively safe and accurate procedures. The risk of major complication (1.3%) following percutaneous splenic biopsy does not exceed that of other solid intra-abdominal organ biopsies, and it has less morbidity and mortality than splenectomy. Both computed tomography and ultrasound can be used to provide image guidance for biopsy and drainage. The safety profile of fine-needle aspiration cytology is better than core needle biopsy, but core biopsy has superior diagnostic accuracy.

The spleen revisited: an overview on magnetic resonance imaging

Despite being well visualized by different cross-sectional imaging techniques, the spleen is many times overlooked during the abdominal examination. The major reason is the low frequency of splenic abnormalities, the majority consisting of incidental findings. There has been a steady increase in the number of performed abdominal magnetic resonance imaging (MRI) studies; therefore, it is important to be familiar to the major MRI characteristics of disease processes involving the spleen, in order to interpret the findings correctly, reaching whenever possible the appropriate diagnosis. The spleen may be involved in several pathologic conditions like congenital diseases, trauma, inflammation, vascular disorders and hematologic disorders, benign and malignant tumors, and other disease processes that focally or diffusely affect the spleen. This paper presents a description and representative MRI images for many of these disorders.

Laparoscopic splenic biopsy--porcine to human studies--using a fibrin sealant technique

INTRODUCTION

Splenic biopsies are not routinely performed because of the risk of severe hemorrhage. The aim of this study was to explore the feasibility of performing laparoscopic splenic biopsies using a fibrin sealant in pigs and then to translate this technique into the clinical setting.

METHOD

Four German Landrace pigs underwent a laparoscopic splenic biopsy using a fibrin sealant to occlude the needle tract. Time to achieve hemostasis and postoperative hemorrhage were assessed.

RESULT

The average time to achieve haemostasis was 15 s (range, 8 to 25 s) with no hemorrhage from the needle tract observed. Subsequently this was translated into the clinical setting where a patient also underwent a laparoscopic splenic biopsy without any adverse effect.

CONCLUSIONS

Laparoscopic splenic biopsy with the application of a fibrin sealant is a safe and efficient technique.

Adenocarcinoma in an intrapancreatic accessory spleen: report of a case

We report a case of adenocarcinoma in an intrapancreatic accessory spleen (IPAS). A 78-year-old woman presented with abdominal discomfort, and investigations revealed an elevated serum carbohydrate antigen 19-9 level, to 161.8 U/ml (normal, <37 U/ml). Ultrasonography showed a heterogeneous echogenic tumor with a vascular hilum. Computed tomography showed a heterogeneously enhanced tumor, 8 cm in diameter, adjacent to the pancreatic body, accompanying a feeding artery arising from the splenic artery, and a drainage vein flowing into the splenic vein. We performed a distal pancreaticosplenectomy. The tumor was surrounded by a fibrous capsule and was in contact with the pancreatic body. Histological examinations revealed invasive growth of adenocarcinoma in a structure identical to the spleen. The results of both radiological and histological examinations suggested that the tumor originated from an intrapancreatic accessory spleen. Extensive examinations revealed no other malignancy, based on which we concluded that the adenocarcinoma was primary. Surgical intervention is strongly recommended when a malignancy in an IPAS cannot be ruled out.

Splenic abscess and multiple brain abscesses caused by Streptococcus intermedius in a young healthy man

We report a case of splenic abscess with multiple brain abscesses caused by Streptococcus intermedius in a healthy young man without any identifiable risk factors, which resolved with percutaneous drainage and antibiotics. Streptococcus intermedius, a member of the Streptococcus anginosus group, is a common commensal organism of the oral cavity and gastrointestinal tract, and it is a known cause of deep-seated infections. Suppurative infections caused by Streptococcus anginosus group are sometimes associated with bacteremia, but hematogenous spread of infection from an occult source leading to concurrent splenic abscess and multiple brain abscesses has never been previously reported in a healthy young individual.