Focal splenic lesions: US findings

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.

The Etiologic Landscape of Lymphoproliferation in Childhood: Proposal for a Diagnostic Approach Exploring from Infections to Inborn Errors of Immunity and Metabolic Diseases

Lymphoproliferation is defined by lymphadenopathy, splenomegaly, hepatomegaly, or lymphocytic organ and tissue infiltration. The most common etiologies of lymphoproliferation are represented by infectious diseases and lymphoid malignancies. However, it is increasingly recognized that lymphoproliferative features can be the presenting sign of rare conditions, including inborn errors of immunity (IEI) and inborn errors of metabolism (IEM). Among IEI, lymphoproliferation is frequently observed in autoimmune lymphoproliferative syndrome (ALPS) and related disorders, common variable immunodeficiency (CVID), activated phosphoinositide 3-kinase δ syndrome, and Epstein-Barr virus (EBV)-related disorders. Gaucher disease and Niemann-Pick disease are the most common IEMs that can present with isolated lymphoproliferative features. Notably, other rare conditions, such as sarcoidosis, Castleman disease, systemic autoimmune diseases, and autoinflammatory disorders, should be considered in the differential diagnosis of patients with persistent lymphoproliferation when infectious and malignant diseases have been reasonably ruled out. The clinical features of lymphoproliferative diseases, as well as the associated clinical findings and data deriving from imaging and first-level laboratory investigations, could significantly help in providing the correct diagnostic suspicion for the underlying etiology. This paper reviews the most relevant diseases associated with lymphoproliferation, including infectious diseases, hematological malignancies, IEI, and IEM. Moreover, some practical indications to orient the initial diagnostic process are provided, and two diagnostic algorithms are proposed for the first-level assessment and the approach to persistent lymphoproliferation, respectively.

Utility of ultrasound in the diagnostic approach to lymphoma with splenic involvement

This paper describes the clinical case of a patient diagnosed with diffuse large B-cell lymphoma with splenic involvement, focusing on the role of abdominal ultrasound (US) in this context. The patient experienced dyspepsia and progressive asthenia over several months so an abdominal US was performed. The US showed multiple heterogeneous and hypoechogenic focal splenic lesions together with a moderate left pleural effusion. Lymphoma was suspected due to these findings and the diagnosis was then confirmed with the performance of a CT scan and a biopsy that revealed the presence of a diffuse large B-cell lymphoma with metastatic disease. Chemotherapy containing rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone was administered and the patient is currently on clinical remission. This study highlights the role of abdominal ultrasound as a useful technique in the non-invasive assessment of this entity, considering an appropriate clinical context and mainly after detecting multiple hypoechogenic splenic lesions in the US.

Evaluation and Classification of Incidentally Detected Splenic Lesions Based on B-Mode and Contrast-Enhanced Ultrasound

PURPOSE

To evaluate B-mode ultrasound (B-US) and contrast-enhanced ultrasound (CEUS) patterns of focal splenic incidentalomas (FSIs), and to correlate ultrasound patterns with benignity and malignancy via histologic examination and/or the clinical course.

MATERIALS AND METHODS

Between 2004 and 2021, 139 consecutive patients with an FSI detected by B-US were investigated additionally with CEUS. On CEUS, the arterial enhancement (AE) of the FSI (hyperenhancement, isoenhancement, hypoenhancement, and absent enhancement) was analyzed. Subsequently, the malignancy rate according to different B-US echo patterns and CEUS perfusion patterns was determined.

RESULTS

The final diagnosis of FSI was malignant in 9/139 (6.5%) and benign in 130/139 (93.5%) cases. The hypoechoic and hyperechoic lesions on B-US with arterial hyperenhancement on CEUS and the echogenic cystic or complex lesions on B-US with predominantly absent enhancement on CEUS were benign in 54/54 (100%) cases. 6/37 (16.2%) hypoechoic lesions on B-US with arterial hypo-/isoenhancement on CEUS and 3/48 (6.3%) of hyperechoic lesions on B-US with an arterial hypo-/isoenhancement on CEUS were malignant.

CONCLUSION

Based on these results, FSIs reveal different malignancy rates depending on the B-US und CEUS patterns, and classification according to these B-US and CEUS patterns may be helpful in further evaluation of an FSI.

[Multimodal ultrasound techniques for the differential diagnosis of splenic lesions - A diagnostic challenge]

BACKGROUND

Splenic tumors are rare and can pose a differential diagnostic challenge, especially as an incidental imaging finding. Due to a lack of large scale biopsy studies the available literature is limited with respect to clear imaging criteria for dignity.

OBJECTIVE

The present work is intended to show the chances of a targeted elicitation of the medical history as well as the possibilities and limitations of multimodal sonography in order to achieve the correct diagnosis of a splenic lesion using simple and gentle methods.

MATERIAL AND METHODS

Selective literature search and clinical case studies.

RESULTS

In the differential diagnostics of focal splenic lesions, information about pre-existing hemato-oncological or inflammatory rheumatological diseases is essential in order to correctly classify incidental findings in particular. In addition to B‑mode ultrasound (B-US) and color-coded Doppler ultrasound (CD-US), contrast-enhanced ultrasound (CEUS) in particular provides crucial differential diagnostic information. While hyperechoic foci in B‑US or arterially hypervascularized splenic foci in CD-US/CEUS are usually benign, hypoechoic and arterially hypoperfused foci in CD-US/CEUS must be further clarified. Although the ultrasound-guided biopsy of the spleen has a higher risk of bleeding than a liver biopsy, it is still the gentlest and most effective method for achieving the histological clarification of splenic lesions when the indications are correct.

CONCLUSION

Through the combination of the medical history and multimodal ultrasound methods, if necessary supplemented by an ultrasound-guided biopsy, focal splenic lesions can be successfully classified in most cases with a direct impact on further clinical procedures.

Acoustic Radiation Force Impulse (ARFI) Elastography of Focal Splenic Lesions: Feasibility and Diagnostic Potential

PURPOSE

Nontraumatic focal splenic lesions (FSL) are rare, and the need for tissue diagnosis must be weighed against the very high risk of bleeding after a splenic biopsy. The aim of this study was to explore the feasibility and diagnostic potential of acoustic radiation force impulse (ARFI) elastography as a noninvasive method for different benign and malignant FSLs. No human studies on the elastographic characteristics of FSL exist.

METHODS

This was a retrospective analysis of 34 patients with FSLs, who underwent abdominal B-mode ultrasound (B-US), contrast-enhanced ultrasound (CEUS), and standardized ARFI examinations between October 2021 and December 2022 at our university hospital. The inclusion criteria were: (i) FSL size ≥ 1 cm; (ii) 10 valid ARFI measurements of the FSL, as well as of the normal splenic parenchyma (NSP) as an in vivo reference; and (iii) diagnostic confirmation of FSL etiology based on histological examination (8/34; 23.5%) or clinical evaluation, which included a clinical and sonographic follow-up (FU), CEUS morphology, and/or morphology on cross-sectional imaging (26/34; 76.5%). CEUS was performed on all patients and the FSLs were classified according to the current guidelines; cross-sectional imaging was available for 29/34 (85.3%). The mean FU duration was 25.8 ± 30.5 months. The mean ARFI velocity (MAV) of the FSL (MAVL), the NSP (MAVP), and the ratio of the MAVL to the MAVP (MAVL/P) were calculated and compared.

RESULTS

Of the 34 FSLs, 13 (38.2%) were malignant (mFSL) and 21 (61.8%) were benign (bFSL). The MAVL of all 34 FSLs (2.74 ± 0.71 m/s) was lower than the MAVP (3.20 ± 0.59 m/s), p = 0.009, with a mean MAVL/P ratio of 0.90 ± 0.34. No significant differences in the MAVL were observed between the mFSL (2.66 ± 0.67 m/s) and bFSL (2.79 ± 0.75 m/s). There were also no significant differences between the MAVP in patients with mFSL (3.24 ± 0.68 m/s) as compared to that in the patients with bFSL (3.18 ± 0.55 m/s). Likewise, the MAV L/P ratio did not differ between the mFSL (0.90 ± 0.41 m/s) and bFSL (0.90 ± 0.30 m/s) groups.

CONCLUSION

ARFI elastography is feasible in evaluating the stiffness of FSLs. The lesions' stiffness was lower than that of the NSP, regardless of the FSL etiology. However, differentiation between benign and malignant FSL with the help of this elastographic method does not appear possible. Larger prospective studies are needed to validate these findings.

Applications of Contrast-Enhanced Ultrasound in Splenic Studies of Dogs and Cats

Simple Summary

Contrast-enhanced ultrasound (CEUS) is a noninvasive imaging technique that has become a reliable tool for identifying and monitoring lesions in both human and animals. In the last decade, its use in veterinary diagnostic imaging has gained increasing importance, and it can be reliable in everyday clinical practice. However, there is a lack of reviews describing existing CEUS results in the study of splenic lesions, which is of particular importance in dogs and cats. This information is important for validating its efficacy, to facilitate decision making related to sampling procedures and diagnosis, or even as a means to select CEUS as an alternative diagnostic tool in specific cases. Our goal was to review the existing studies of CEUS applications for splenic ultrasound studies in cats and dogs, present these results in a systematic manner, and combine this information into practical guidelines that can be used to help diagnosis and interpretation in both clinical cases and research.

Abstract

Contrast-enhanced ultrasound (CEUS) is an emerging technology in veterinary medicine involving the administration of intravenous contrast agents, and it is increasingly recognized for its high potential as a diagnostic imaging tool for small animals. This exam is easy and quick to perform, safe and reliable, and allows for the differentiation of lesions. It permits the identification of lesions that may require more invasive procedures, from those that can be safely dismissed to those that can be followed-up with ultrasound imaging. Although it has been extensively reviewed for use in human medicine, there is an overall lack of information about the application of this technique for cats and dogs, particularly in splenic studies, which can be particularly important for small animals. The present review describes and summarizes the CEUS applications used for splenic analysis in cats and dogs, providing a basic overview of CEUS technology with examples of common and uncommon features of focal splenic lesions. It also systematically gathers the results obtained for benign and malignant splenic lesions described in the literature, whilst providing guidelines for their interpretation. Furthermore, it presents the advantages of using CEUS for splenic analysis in cats and dogs and the main factors that may influence the quality of the imaging and the accuracy of the diagnosis. This type of knowledge can be used to provide a framework to help veterinarians make informed decisions regarding the use of this emerging technique for splenic lesions, guiding their interpretation of CEUS findings in the splenic ultrasounds of cats and dogs.

Surgical treatment of benign splenic lesions in pediatric patients: a case series of 30 cases from a single center

Background

Benign splenic lesions are rarely encountered. This study aimed to review the clinical characteristics and surgical outcomes in a case series of 30 pediatric patients.

Methods

From January 1st, 2001 to December 31st, 2021, 30 pediatric patients from a single center were consecutively included. Electronic medical records were reviewed and patients were followed up. Clinical presentations, imaging features, surgical procedures, pathological diagnoses, and prognoses were summarized. The lesion locations and 7-day postoperative platelet levels were compared between total and partial splenectomy patients.

Results

Eighteen males and twelve females were included, with mean age at surgery 116.4 ± 43.6 months. The clinical presentations included abdominal pain (16/30), splenomegaly (6/30), skin petechia (2/30), hemolytic jaundice (1/30), and no symptoms (5/30). Pathological diagnoses included congenital epithelial cyst (CEC, 17/30), vascular malformation (8/30), sclerosing angiomatoid nodular transformation (SANT, 3/30), hamartoma (1/30), and leiomyoma (1/30). Patients undergone total splenectomy were more likely to have a lesion involving the hilum than those undergone partial splenectomy (68.4% vs 31.6%, P = 0.021). The 7-day postoperative platelet level was higher in total splenectomy patients than partial splenectomy patients (adjusted means 694.4 × 10⁹/L vs 402.4 × 10⁹/L, P = 0.002).

Conclusions

Various clinical characteristics of pediatric benign splenic lesions are summarized. The most common pathological diagnoses are congenital epithelial cyst and vascular malformation. Partial and total splenectomy result in good prognosis with a low recurrence rate, and the former is preferred to preserve splenic function if possible.

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.

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.

Identification of secondary splenic lymphoma with contrast-enhanced ultrasound in the pediatric population. A case report

Contrast-enhanced ultrasound scan (CEUS) is the application of ultrasound contrast agents (UCAs) to traditional ultrasound. Our aim is to report the use of CEUS for a prompt assessment of a suspected secondary splenic lymphoma in a child, which, in our experience, has allowed an accurate description of the parenchymal perfusion and vascularization pattern, leading to a confident diagnosis. We suggest that CEUS will replace Magnetic resonance imaging (MRI) or Computed tomography (CT) as standard imaging option for differential diagnosis of spleen lesions in pediatric population. As a result this will lead to decreasing the overall use of ionizing radiation and reducing the time interval to a certain diagnosis.

WFUMB Position Paper-Incidental Findings, How to Manage: Spleen

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental Imaging Findings-The Role of Medical Ultrasound." IFs are less commonly encountered in the spleen than in many other abdominal organs but remain a frequent dilemma in clinical practice. A histological diagnosis is rarely necessary for patient management. Many IFs, such as secondary spleens and splenic cysts, are harmless and do not require any further investigation. The diagnosis of many other focal splenic lesions is, however, often problematic. The following overview is intended to illustrate a variety of incidentally detected spleen pathologies such as size variants, shape variants, secondary spleens, focal splenic lesions and splenic calcifications. It should aid the examiner in establishing the diagnosis. Moreover, it should help the ultrasound practitioner decide which pathologies need no further investigation, those requiring interval imaging and cases in which immediate further diagnostic procedures are required.

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.

[Spleen biopsy: "pros and cons" or better "when and when not?"]

Due to the relatively high complication rate, the necessity of a spleen biopsy is controversially discussed. In establishing its indication, the clinical background and performed diagnostics must be considered. Based on the medical history, imaging procedures and sonographic course, different clinical scenarios are conceivable. The aim of this review is to describe the indications of splenic biopsy considering various clinical scenarios.

Maternal and fetal incidental findings on antenatal magnetic resonance imaging

BACKGROUND

Magnetic resonance imaging (MRI) examinations are increasingly used in antenatal clinical practice. Incidental findings are a recognized association with imaging and although in some circumstances their identification can alter management, they are often associated with increased anxiety, for both patient and clinician, as well as increased health care costs.

OBJECTIVE

This study aimed to evaluate the incidence of unexpected findings in both the mother and fetus during antenatal MRI examinations.

MATERIALS AND METHODS

A retrospective study was undertaken over a five-year period at St.. Thomas' Hospital in London. Maternal incidental findings were recorded from all clinical reports of all fetal MRIs performed (for clinical reasons and in healthy volunteers) during this period. Fetal incidental findings were recorded only in cases where women with uncomplicated pregnancies were participating as healthy volunteers.

RESULTS

A total of 2,569 MRIs were included; 17% of women had maternal incidental findings. Of these, 1,099 were women with uncomplicated pregnancies who undertook research MRIs as healthy volunteers; fetal incidental findings were identified in 12.3%.

CONCLUSION

Incidental findings are a common occurrence in antenatal MRI. Consideration should be given to counseling women appropriately before imaging and ensuring that robust local protocols are in place for follow-up and further management of such cases.

Abdominal Involvement in Children With Bacteriologically Confirmed Tuberculosis: A Five-year Experience From Cape Town, South Africa

BACKGROUND

Abdominal tuberculosis (TB) in children is poorly described and often poses a diagnostic challenge. We evaluated abdominal involvement in children presenting with bacteriologically confirmed TB.

METHODS

We undertook a retrospective study at Tygerberg Hospital, Cape Town, from January 1, 2014, through December 31, 2018, of all children (<13 years) diagnosed with bacteriologically confirmed TB, in whom abdominal involvement was found. Demographic and clinical data were collected through folder review, laboratory records and imaging reports.

RESULTS

Of 966 children with bacteriologically confirmed TB, 111 (11.5%) had abdominal involvement; 16 (14.4%) were excluded from further analysis because of lack of clinical data. The median age of the remaining 95 children was 43 months (interquartile range 20-94); 26 (27%) were HIV positive. The main gastrointestinal symptoms/signs were weight loss (84.2%), abdominal distention (54.7%), hepatomegaly (60.0%) and abdominal pain (26.3%). The main pathologic types were intra-abdominal lymph nodes (68.4%), solid organ involvement (54.7%), peritoneal type (23.2%) and intestinal type (10.5%). Splenic abscesses and solid organ involvement on ultrasonography were more common in HIV-positive children (P < 0.001 and P = 0.008, respectively). Liver abscesses were associated with age less than 5 years (P = 0.03), while abdominal lymphadenopathy on ultrasonography was more common in children older than 5 years (P = 0.038). Abdominal specimens were collected in an attempt to identify Mycobacterium tuberculosis in 15 of 95 (15.8%) patients and were positive in 13 of 15 (86.7%).

CONCLUSIONS

Over 10% of children with confirmed TB had abdominal involvement. Abdominal TB should be considered in any pediatric TB case with abdominal symptoms, and ultrasonography should be the radiologic study of choice.

Vascular pattern and diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in spleen alterations

BACKGROUND

Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique in order to clarify rare focal splenic lesions (FSL). CEUS is a safe and cost-effective modality for assessment of perfusion.

OBJECTIVE

To validate contrast enhancement pattern and evaluate the diagnostic accuracy of CEUS in unclear FSL.

METHODS

CEUS examinations of the spleen in 50 patients between 2012 and 2018 were included in the study. Examinations were performed using B-mode, colour-coded Doppler ultrasound (CCDS) and CEUS after injection of sulphur hexafluoride microbubbles and interpreted in consensus by two experienced radiologists. Reference standard was defined as histopathological report and clinical course (treatment response, long term follow up).

RESULTS

All patients were successfully examined by CEUS without an adverse reaction. CEUS presented the correct differentiation of benign and malignant alterations in 49/50 (98%). Lesion washout was found in all malignant but also 16.7% of all benign lesions. Matched to the histopathological report and clinical follow up, CEUS represented a sensitivity of 100% (95% -CI, 57-100), a specificity of 98% (95% -CI, 88-100), a positive predictive value (PPV) of 83% (95% -CI, 44-97) and a negative predictive value (NPV) of 100% (95% -CI, 92-100).

CONCLUSION

CEUS may provide additional information by visualization of dynamic contrast enhancement pattern to differentiate benign and malignant lesions. Nevertheless, established criteria for malignancy (early enhancement or washout) in FSL should be considered with caution since they are also found in benign lesions.

Point-of-Care Ultrasound Predictors for the Diagnosis of Tuberculosis in HIV-Positive Patients Presenting to an Emergency Center

BACKGROUND

The performance of point-of-care ultrasound (PoCUS) to diagnose HIV-associated tuberculosis has not been evaluated in large prospective studies. We determined the diagnostic accuracy of individual PoCUS features, performed an external validation of the focused assessment with sonography for HIV/TB (FASH) protocol, and determined independent PoCUS predictors of HIV-associated tuberculosis appropriate for use by emergency center practitioners.

SETTING

A cross-sectional diagnostic study was performed at the emergency center of Khayelitsha Hospital (Cape Town, South Africa).

METHODS

HIV-positive adults with the suspicion of having tuberculosis were prospectively enrolled. PoCUS was performed according to a standardized protocol. Reference standard was the detection of Mycobacterium tuberculosis using Xpert MTB/RIF or culture.

RESULTS

We enrolled 414 participants: 243 female, median age 36 years, median CD4 cell count 86/mm, and 172 (42%) had tuberculosis. Sensitivity and specificity were ≥1 individual PoCUS feature [73% (95% CI: 65 to 79), 54% (95% CI: 47 to 60)], FASH protocol [71% (95% CI: 64 to 78), 57% (95% CI: 50 to 63)]. Independent PoCUS predictors identified were intra-abdominal lymphadenopathy of any size (aDOR 3.7 (95% CI: 2.0 to 6.7)], ascites [aDOR 3.0 (95% CI: 1.5 to 5.7)], and pericardial effusion of any size [aDOR 1.9 (95% CI: 1.2 to 3.0)]. The c-statistic for the derivation model was 0.680 (95% CI: 0.631 to 0.729), compared with 0.630 (95% CI: 0.576 to 0.684) of the FASH protocol. Two or more independent PoCUS predictors had 91% (95% CI: 86 to 94) specificity.

CONCLUSION

The presence of 2 or more independent PoCUS predictors (intra-abdominal lymphadenopathy, ascites, and pericardial effusion) had moderate discrimination for HIV-associated tuberculosis in patients presenting to the emergency center.

Conventional Ultrasound and Contrast-Enhanced Ultrasound in the Diagnosis of Splenic Diseases: A Systematic Review and Meta-analysis

Accurate diagnosis of splenic diseases is important for timely and accurate treatment. The objective of this study was to compare the accuracy of contrast-enhanced ultrasound (CEUS) and conventional ultrasound (US) in detecting splenic lesions. A systematic literature search was undertaken, and 8 studies met the inclusion criteria. The sensitivity and specificity of the consolidated results of CEUS were 0.95 (95% confidence interval [CI], 0.92-0.97) and 0.97 (95% CI, 0.90-0.99), respectively (I² = 27.4%; area under the curve [AUC] from a summary receiver operating characteristic curve = 0.97). The sensitivity and specificity of the consolidated results of conventional US were 0.70 (95% CI, 0.56-0.80) and 0.96 (95% CI, 0.76-0.99; I² = 83.4%; AUC = 0.84). In this systematic review and meta-analysis, the sensitivity and specificity of CEUS were higher than those of conventional US in diagnosing splenic lesions. Contrast-enhanced US is a promising method for accurately diagnosing splenic lesions.

A Mysterious Case of an Infarcted Spleen due to Kissing Disease: A Rare Entity

Viruses are long known to be leading causes of self-limiting infections. Infectious mononucleosis (IM) caused by the Epstein-Barr virus (EBV) is, however, no exception. The ailment is caused by a DNA virus belonging to the Herpesviridae family. As stated earlier, the infection is usually self-limited with mononucleosis-like symptoms such as fever, sore throat, lymphadenopathy (LAD), rash, headache, etc. In rare instances, it can lead to severe complications. The organ of prime importance following the infection is spleen. There are occasions where splenic injuries can lead to rupture, deeming to emergency surgical interventions. At other times, a rare entity may also be seen that constitutes an infarction within the splenic substance. We present this rare finding in a 20-year-old male patient with a left upper quadrant (LUQ) pain, cervical LAD, and sore throat who was brought to the emergency department. On physical examination, mild tenderness was observed in the LUQ with an inflamed throat and palpable cervical and occipital lymph nodes. Laboratory investigations suggested lymphocytosis with no blast cells, lactic acidosis, and mild acute kidney injury. A contrast-enhanced computed tomography scan demonstrated an enlarged spleen with wedge-shaped hypodense areas, which led to a diagnosis of splenic infarction secondary to infectious mononucleosis. Keeping in mind the symptomatology and the age of the patient, a bunch of differentials were needed to be ruled out. Out of a series of investigations done on the patient, EBV serology for IgM was positive. The patient was conservatively treated with a complete resolution of symptoms in one month. Our case adds to the literature the finding of a rare etiology of splenic infarction secondary to IM and the importance of stepwise and cost-effective investigations to avoid unnecessary workup when needed.

Clinical use of contrast-enhanced ultrasound beyond the liver: a focus on renal, splenic, and pancreatic applications

Contrast-enhanced ultrasound (CEUS) is a relatively novel, but increasingly used, diagnostic imaging modality. In recent years, due to its safety, quickness, and repeatability, several studies have demonstrated the accuracy, specificity, and sensitivity of CEUS. The European Federation of Societies for Ultrasound in Medicine and Biology has recently updated the previous guidelines from 2012 for the use of CEUS in non-hepatic applications. This review deals with the clinical use and applications of CEUS for the evaluation of non-hepatic abdominal organs, focusing on renal, splenic, and pancreatic applications.

Renal Cell Carcinoma Follow-Up - Is it Time to Abandon Ultrasound?

Background

We wished to compare the efficacy of ultrasound versus intravenous contrast-enhanced computed tomography (CT) for detecting recurrent renal cell carcinoma (RCC) by identifying patients presenting with such tumor burden and to evaluate the utility of these imaging modalities in these circumstances.

Methods

Patients who developed local and/or distant recurrences following surgical intervention for RCC were identified. The imaging regimen utilized during post-operative surveillance was analyzed to determine whether recurrent disease was identifiable on ultrasound or CT or both.

Results

Of the 22 patients with recurrent RCC, 16 had previously undergone radical nephrectomy and 6 had undergone partial nephrectomy. Median duration to RCC recurrence was 28.5 months (range 2-66 months). Fourteen patients (64%) underwent ultrasound during their follow-up surveillance protocol and 1 case of disease recurrence was detected by ultrasound before subsequent con-frmation with CT. All 22 patients underwent CT as a routine component of their follow-up surveillance protocol and all recurrences were detected by this modality. Six patients had recurrence in their ipsilateral kidney after partial nephrec-tomy - five had undergone ultrasound in their surveillance protocol and this modality failed to detect a recurrence in four of these patients.

Conclusion

Ultrasound is inferior to CT for detecting recurrent RCC. CT should be recognized as the standard diagnostic modality during post-operative surveillance, in contradiction to what is recommended in many guidelines.

[Imaging of abdominal tumors in childhood and adolescence : Part I: Background, hepatic, splenic and pancreatic tumors]

In comparison to adult patients, other specific entities of abdominal tumors occur in childhood and adolescence. These include malignant tumors originating from embryonic tissue, such as hepatoblastoma. Some of the abdominal tumors are already diagnosed prenatally or in neonates. Sonography functions as the primary radiological basic diagnostics of pediatric abdominal space-occupying lesions, if necessary supplemented by administration of ultrasound contrast medium or the implementation of novel techniques (e.g. innovative Doppler and elastography procedures). Magnetic resonance imaging (MRI) is used for a comprehensive and detailed depiction of the tumors including the question of resectability and vascular supply. Various weighting and different MRI sequences are used in order to be able to assess the signal behavior of the tumor and therefore the possible presence of calcification, necrosis or hemorrhage, the behavior of dynamic contrast enhancement, and the presence and extent of diffusion disorders. This information is decisive in order to be able to assess the entity and malignancy of the abdominal space-occupying lesion. Rare but relevant tumors with respect to the entity occur in childhood and adolescence in the abdominal organs liver, spleen and pancreas.

A 28-Year-Old Woman with Ascites and Multiple Focal Spleen Lesions

Serous effusions complicating the course of lymphomas occur commonly in the pleural space but seldom in the peritoneum, where they most often present as chylous ascites with diagnostic cytology. Almost invariably, in these rare cases, the serum to ascites albumin gradient is low. We describe a 28-year-old woman with anasarca, ascites and a serum to ascites albumin gradient of 1.1 g/dl, consistent with portal hypertension. No tumour cells were detected in the ascitic fluid. However, a CT scan of the chest and abdomen disclosed liver and spleen enlargement and multiple enlarged retroperitoneal lymph nodes, suspicious for a lymphoproliferative disorder. Bone marrow aspiration and biopsy were not diagnostic, so a decision was made to proceed with a splenectomy despite the onset of low-grade disseminated intravascular coagulation.

Surgery was uneventful. Diffuse large B cell lymphoma was diagnosed. A liver biopsy taken at the time of surgery demonstrated that the liver parenchyma was massively infiltrated by reactive T lymphocytes surrounding rare large CD20+ tumour cells. This infiltrate had likely led to increased portal pressure attended by ascites formation, which resolved completely after chemotherapy. The case emphasizes the rewards of pursuing a diagnosis supported by a high prior probability even in the presence of apparently discordant laboratory findings, as well as the importance of performing a diagnostic splenectomy in case of splenomegaly with unexplained focal lesions.

Focal spleen lesions in visceral leishmaniasis, a neglected manifestation of a neglected disease: report of three cases and systematic review of literature

BACKGROUND

The Mediterranean area is endemic for the zoonotic form of visceral leishmaniasis (VL) caused by Leishmania infantum, a species which has been recently associated with unexpected epidemiological and clinical features.

METHOD

We report the result of a systematic review of the literature on VL unusually presenting with spleen focal lesions, including three previously unpublished cases.

RESULTS

A total of 28 cases of VL with multiple spleen focal lesions were retrieved. Twenty-six (93%) were acquired in the Mediterranean area, where L. infantum is endemic. Thirteen cases were diagnosed in children, and the remaining 15 cases in middle-aged adults, of whom 9 were immunosuppressed. Four patients (14%) underwent diagnostic splenectomy, while the diagnosis was confirmed by less invasive techniques in the remaining patients. The most common radiological patterns were: multiple subcentimetric or centimetric spleen lesions (size ≤ 1 cm in 14 of 19 cases, 74%), hypoechoic at ultrasonography (25 of 26 cases, 99%) and hypodense at CT scan (9 of 10 cases, 90%). PET-CT (available for four patients) showed an intense FDG spleen uptake. MRI and contrast-enhanced ultrasonography, available for two and one cases each, showed complex patterns.

CONCLUSIONS

VL must be added to the list of possible differential diagnosis of spleen focal lesions and health care provider awareness about this condition will avoid unnecessary invasive diagnostic procedures.

Ultrasonography of the pediatric spleen: a pictorial essay

In infants and children, the spleen is involved in many pathological processes, whether those processes are isolated or related to systemic diseases. Pathology of the pediatric spleen includes congenital anomalies, splenomegaly, trauma, focal lesions, infarction, and tumors. Ultrasonography (US) is a widely available, fast, noninvasive imaging technique to assess the size, shape, and position of the spleen, as well as to define splenic echotexture. US is capable of screening for splenic disorders without the risk of ionizing radiation; it is the initial imaging examination performed to evaluate suspected splenic pathology, providing clinicians with helpful decisional support. US plays an important role in the detection of even very small amounts of hemoperitoneum, a herald of significant abdominal organ injury, in pediatric blunt abdominal trauma. Moreover, contrast-enhanced US may allow early detection of splenic injuries, ideally minimizing children's risk from radiation exposure. This pictorial essay illustrates the normal ultrasound appearance of the pediatric spleen and the sonographic findings which may guide clinicians to a correct diagnosis of pathologic conditions.

The Incidental Splenic Mass at CT: Does It Need Further Work-up? An Observational Study

Purpose To evaluate whether an incidentally noted splenic mass at abdominal computed tomography (CT) requires further imaging work-up. Materials and Methods In this institutional review board-approved HIPAA-compliant retrospective study, a search of a CT database was performed for patients with splenic masses at CT examinations of the abdomen and chest from 2002 to 2008. Patients were divided into three groups: group 1, patients with a history of malignancy; group 2, patients with symptoms such as weight loss, fever, or pain related to the left upper quadrant and epigastrium; and group 3, patients with incidental findings. Patients' CT scans, follow-up examinations, and electronic medical records were reviewed. Final diagnoses of the causes of the masses were confirmed with imaging follow-up (83.9%), clinical follow-up (13.7%), and pathologic examination (2.4%). Results This study included 379 patients, 214 (56.5%) women and 165 (43.5%) men, with a mean age ± standard deviation of 59.3 years ± 15.3 (range, 21-97 years). There were 145 (38.3%) patients in the malignancy group, 29 (7.6%) patients in the symptomatic group, and 205 (54.1%) patients in the incidental group. The incidence of malignant splenic masses was 49 of 145 (33.8%) in the malignancy group, eight of 29 (27.6%) in the symptomatic group, and two of 205 (1.0%) in the incidental group (P < .0001). The incidental group consisted of new diagnoses of lymphoma in one (50%) patient and metastases from ovarian carcinoma in one (50%) patient. Malignant splenic masses in the incidental group were not indeterminate, because synchronous tumors in other organs were diagnostic of malignancy. Conclusion In an incidental splenic mass, the likelihood of malignancy is very low (1.0%). Therefore, follow-up of incidental splenic masses may not be indicated. ^© RSNA, 2018.

Characteristics and Echogenicity of Clinical Ultrasound Contrast Agents: An In Vitro and In Vivo Comparison Study

OBJECTIVES

To compare physicochemical characteristics and in vitro and in vivo contrast-enhanced ultrasound imaging performance of 3 commercially available ultrasound contrast agents: SonoVue (Bracco Imaging SpA, Colleretto Giacosa, Italy; also marketed as Lumason in the USA), Definity (Lantheus Medical Imaging, North Billerica, MA) and Optison (GE Healthcare AS, Oslo, Norway).

METHODS

Physicochemical characteristics were measured with a Multisizer Coulter Counter (Beckman Coulter, Fullerton, CA). Two ultrasound systems (Aplio 500; Toshiba Medical Systems Corp, Tochigi-ken, Japan; and Logiq E9; GE Healthcare, Little Chalfont, England) were used with different transducers. Contrast enhancement was measured in vitro by dose-ranging measurements using a custom-built beaker setup; in vivo imaging performances were compared in pigs (heart and liver) and rabbits (liver). Quantitative analyses were performed with VueBox quantification software (Bracco Suisse SA, Plan-les-Ouates, Switzerland).

RESULTS

Measured physicochemical characteristics were in agreement with those provided by the manufacturers. In vitro data demonstrated that the performance of SonoVue was similar to or better than that of Definity but superior to Optison (normalized scattered power 2- to 10-fold higher with SonoVue). Similar results were obtained in vivo, although the duration of enhancement in the pig heart was longer for SonoVue compared to Definity, and quantitative analysis revealed higher enhancement for SonoVue (1.5-fold increase). For liver imaging, SonoVue and Definity showed similar contrast enhancement and duration of enhancement, but compared to Optison, both peak enhancement and duration of enhancement were superior for SonoVue (up to 2-fold increase).

CONCLUSIONS

Imaging performance of SonoVue was similar to or slightly better than that of Definity, but it was superior to Optison for the conditions used in this study.

[A case of splenic hamartoma diagnosed by contrast-enhanced ultrasonography and magnetic resonance imaging]

Splenic hamartoma is a very rare benign tumor, which is usually found incidentally after splenectomy or autopsy. Although percutaneous needle biopsy can be performed, it carries a high risk of bleeding after the procedure. Therefore, diagnosis is usually made by surgical resection. Herein, we report a case of splenic hamartoma diagnosed by magnetic resonance imaging and contrast-enhanced ultrasonography, which enables visualization of the unique signals of microbubbles in the vessels in real time. Relevant literature is also reviewed.

A Rare Cause of Acute Abdominal Pain: Splenic Infarct (Case Series)

Splenic infarcts are rare cases. It may not be noticed in the emergency department because the clinical picture is likely to mimic various acute abdominal pains. The splenic infarct is often the result of systemic thromboembolism associated with cardiovascular disorders. The aim of this study is to present an evaluation of the patients that presented to the emergency department (ED) with abdominal pain and were diagnosed with splenic infarct.

18F-FDG PET/CT Findings in a Splenic Lymphangioma

A 16-year-old girl with abdominal pain for 3 years underwent FDG PET/CT scan for evaluating identifiable origin. The images showed multifocal, subcapsular thin-walled low-attenuation masses on CT and focal, slight increased ¹⁸F-FDG uptake on PET with an SUV(max) of 3.0. Based on the findings, malignancy cannot be excluded. Then, pathologic examination was performed, and it was identified to be splenic lymphangioma. We herein presented the FDG PET/CT findings of this splenic lymphangioma, which is a rare benign vascular tumor and commonly caused by congenital malformation of the lymphatic vessels.

Contrast-enhanced sonography with Sonazoid as a new diagnostic tool for splenic hamartoma: a single case report

Detection of reticuloendothelial system (RES) cells is essential for the differential diagnosis of splenic hamartoma. Among the imaging techniques using contrast agents phagocytosed by RES cells, contrast-enhanced ultrasonography (CEUS) with Sonazoid is less invasive and less costly than (99m)Tc-labeled colloid scintigraphy. We report a case of non-symptomatic splenic hamartoma in a 40-year-old woman detected as an abdominal tumor by screening ultrasonography. The tumor was 4 cm in diameter, round, slightly hypoechoic, and associated with a cystic lesion. The tumor region was stained on enhanced computed tomography with prolonged enhancement, while the cystic lesion was not. The mass appeared as mainly isointense with partial hyperintensity on T1-weighted and as a mixed hypo- and hyperintense region on T2-weighted magnetic resonance images. (99m)Tc-labeled colloid scintigraphy demonstrated uptake in only the tumor region. CEUS with Sonazoid revealed that the tumor was mainly hypervascular with non-enhanced areas in the early vascular phase, but the hypervascular region appeared also as a hyperechoic area (indicating microbubble phagocytosis) in the post-vascular phase. Thus, CEUS with Sonazoid revealed all three cardinal features of splenic hamartoma: hypervascularity, presence of RES cells, and tissue heterogeneity. Splenectomy and histopathology confirmed the presence of a splenic hamartoma with associated hematoma. CEUS with Sonazoid is a promising new diagnostic tool for splenic hamartoma.

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.

Diagnosis and treatment challenges in a patient with splenic tumor and chronic viral hepatitis

Non-Hodgkin lymphoma is a cancer of the lymphatic tissue located in various parts of the body: lymph nodes, spleen, thymus, adenoids, tonsils, and bone marrow. The disease occurs mainly in adults, with a higher incidence within the age range of 45 to 60 years. We present a clinical case of non-Hodgkin lymphoma diagnosed in a patient with chronic viral hepatitis B and D. The particularity of this case consists in the diagnosis of primitive spleen lymphoma, described in less than 1% of the cases, and also the difficult antiviral therapy recommendation for the liver disease, given the associated co-morbidity.

ABBREVIATIONS

NHL = Non-Hodgkin lymphoma, HDV = Hepatitis delta virus, HCV = Hepatitis C virus, HBV = Hepatitis B virus, CT = Computerized tomography, CEUS = Contrast enhanced ultrasonography, CHOP = cyclophosphamide, doxorubicin, vincristine, prednisone, R-CHOP = cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab.

Primary lymphoma of the spleen mimicking simple benign cysts: contrast-enhanced ultrasonography and other imaging findings

We report on a case of incidentally detected primary splenic lymphoma mimicking simple benign cysts on abdominal ultrasonography. On contrast-enhanced ultrasonography (CEUS), the lesions showed isoenhancement in the arterial phase with progressive washout and marked hypoenhancement in the parenchymal phase. This pattern enabled us to suspect the malignant nature of the disease, thus preventing a dangerous misdiagnosis. Accordingly, further characterization with other imaging studies (computed tomography, magnetic resonance imaging, and positron emission tomography) was pursued based on CEUS and taking into account the patient's clinical picture and medical history. Collectively, imaging data led us to a diagnosis of suspected primary splenic malignancy, most probably lymphoma, which was histologically confirmed on the surgical specimen after splenectomy.