Nonneoplastic, benign, and malignant splenic diseases: cross-sectional imaging findings and rare disease entities

Primary splenic angiosarcoma presenting as thrombocytopenia

Primary splenic angiosarcoma is an extremely rare and aggressive vascular neoplasm associated with high rates of metastasis. A male patient in his 70s presented with thrombocytopenia. Physical examination and blood tests were non-revealing. A large splenic lesion was found on imaging, and splenectomy confirmed the diagnosis of splenic angiosarcoma. A PET scan and brain MRI showed no evidence of metastasis. The patient is now under surveillance with imaging. Primary splenic angiosarcoma presents a significant clinical challenge due to its aggressive nature and nonspecific symptoms, with outcomes typically poor despite treatment efforts. Chemotherapeutic options lack consensus due to the rarity of the disease. Most patients present with metastases, and treatment primarily involves resection, with adjuvant therapies considered based on risk factors. This case underscores the importance of considering rare malignancies in the differential diagnosis of patients presenting with thrombocytopenia and nonspecific symptoms. Early detection and prompt intervention are fundamental in improving outcomes.

Splenic imaging and non-vascular intervention: when to intervene on the spleen and how to do it safely

Cross-sectional interventional radiology (CSIR) for the spleen has evolved over the past two decades. Contemporary data show that CT- and US-guided splenic procedures are safer than once assumed, allowing for biopsy and drainage when clinically appropriate. Prior to intervention, however, close imaging evaluation of splenic lesions is required in order to recognize definitively benign, "do not touch" lesions as well as suspicious features that might warrant biopsy. This manuscript will first focus on imaging workup and decision-making for splenic lesions, and then discuss modern CSIR techniques to maximize both safety and yield.

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.

Diagnostic ability of [18F]FDG PET/CT for distinguishing benign from malignant spleen lesions

OBJECTIVES

[18F]Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a non-invasive imaging modality used in the differential diagnosis of splenic lesions, although ideal parameters and thresholds remain unclear. The present study evaluated the ability of [18F]FDG PET/CT, including its visual and quantitative parameters, to differentiate between benign and malignant splenic lesions.

METHODS

Patients who underwent [18F]FDG PET/CT following the detection of splenic lesions on contrast-enhanced CT were retrospectively analysed. Visual parameters assessed on [18F]FDG PET/CT included whole spleen uptake intensity, lesion multiplicity, and lesion uptake, and quantitative parameters included maximum standardised uptake value (SUVmax), lesion-to-background ratio (LBR), metabolic tumour volume (MTV), total lesion glycolysis (TLG), and lesion size. Parameters differentiating between benign and malignant lesions were evaluated by Pearson's chi-square test, Mann-Whitney U-test, and receiver operating characteristics (ROC) curve analysis.

RESULTS

Splenic lesion uptake (p = 0.001) was the only visual parameter significantly distinguishing between benign and malignant lesions. ROC curve analysis demonstrated that SUVmax had the largest area under the ROC, 0.91 (p < 0.001), with an optimal cut-off > 5.3 having a sensitivity of 90.3% and a specificity of 80.6%. Subgroup analysis of malignant lesions showed that SUVmax (p = 0.013), LBR (p = 0.012), and TLG (p  = 0.034) were significantly higher in splenic lymphomas than in splenic metastases.

CONCLUSION

Of the [18F]FDG PET/CT parameters investigated, SUVmax had the highest accuracy in diagnosing malignant splenic lesions and was significantly higher in splenic lymphomas than in splenic metastases. Visual determination of [18F]FDG uptake by splenic lesions may be an easily evaluated parameter.

CLINICAL RELEVANCE STATEMENT

SUVmax and visual grade of [18F]FDG PET/CT help to differentiate spleen lesions. [18F]FDG PET/CT is useful for discriminating between benign and malignant spleen lesions.

KEY POINTS

Many splenic lesions are difficult to diagnose on anatomical imaging, with histopathologic analyses are required. SUVmax of PET/CT provided the diagnostic ability to differentiate between benign and malignant splenic lesions. More than normal spleen uptake can be a convenient parameter to diagnose malignant spleen lesions.

Stroma-derived neoplasms and pseudoneoplastic lesions of the spleen: a select review of pathologic and CT/MRI findings

A wide spectrum of benign and malignant primary mesenchymal tumors and tumor-like lesions of the spleen has been recently included under the umbrella term 'stroma-derived' neoplasms and tumor-like lesions. These include dendritic cell neoplasms such as follicular dendritic cell sarcoma, EBV-positive inflammatory follicular dendritic cell sarcoma, and fibroblastic reticular cell tumor; smooth muscle and myofibroblastic lesions such as inflammatory pseudotumor, EBV-associated smooth muscle tumor and undifferentiated pleomorphic sarcoma as well as a diverse spectrum of vascular and vascular-stromal tumors and tumor-like lesions. While some tumor and tumor-like lesions are unique to the spleen, others may also occur in diverse extra-splenic viscera. These tumors and tumor-like lesions demonstrate characteristic histopathology, immunocytochemistry and biological behavior. While cross-sectional imaging studies allow detection, staging and limited characterization of these splenic lesions, histopathological confirmation permits optimal management and surveillance strategies.

Sclerosing angiomatoid nodular transformation (SANT) of the spleen: a case report

SANT is a rare, non-lymphoid, benign entity, originating from the red pulp of the spleen. It is characterized by the presence of vascular nodules surrounded by a stroma of collagen fibers. It was introduced as a distinct disease entity by Martel et al in 2004, after the histopathological examination of 25 cases. Symptoms are unspecific, and in most cases, it is incidentally diagnosed, mostly in patients who undergo imaging for other underlying conditions. Moreover, radiological findings are usually inconclusive, and a definite diagnosis is established through histopathological examination. We herein report the case of a 76-year-old female diagnosed with stage I rectal cancer who was subsequently diagnosed with a splenic lesion after a Computed Tomography (CT) scan that was performed for follow-up purposes. Different imaging modalities were employed for further assessment; however, findings were inconclusive and the possibility of metastatic disease could not be excluded. The patient was referred for splenectomy and the diagnosis of SANT was established through histopathological examination.

Spectrum of Heterotopic and Ectopic Splenic Conditions

A spectrum of heterotopic and ectopic splenic conditions may be encountered in clinical practice as incidental asymptomatic detection or symptomatic diagnosis. The radiologist needs to be aware of these conditions and their imaging characteristics to provide a prompt correct diagnosis and avoid misdiagnosis as neoplasm or lymphadenopathy. Having a strong knowledge base of the embryologic development of the spleen improves understanding of the pathophysiologic basis of these conditions. Spleen-specific imaging techniques-such as technetium 99m (99mTc)-labeled denatured erythrocyte scintigraphy, 99mTc-sulfur colloid liver-spleen scintigraphy, and MRI with ferumoxytol intravenous contrast material-can also be used to confirm the presence or absence of splenic tissue. Heterotopic splenic conditions include splenules and splenogonadal fusion (discontinuous or continuous forms). These heterotopic conditions are caused by incomplete fusion of the splenic primordia (splenule) and abnormal fusion of the gonadal and splenic tissue (splenogonadal fusion). Ectopic splenic conditions arise in patients with a prior splenic injury (splenosis), laxity or maldevelopment of the splenic ligaments (wandering spleen), or heterotaxy syndromes (polysplenia and asplenia). Importantly, these heterotopic and ectopic splenic conditions can also manifest with complications, including vascular torsion and rupture. ©RSNA, 2024.

Multimodality Imaging Features of Various Splenic Lesions: Clinical and Histopathologic Correlation

The spleen is occasionally referred to as the 'forgotten organ' because splenic lesions are less common and encountered rarely compared to pathologies of other abdominal solid organs. Therefore, although well-demonstrated using various abdominal imaging modalities, radiologists tend to be less familiar with splenic diseases, making interpretation challenging. This study aimed to review common and uncommon splenic diseases and illustrate the multimodal imaging (including ultrasonography, CT, MRI, and PET/CT) features of these lesions in correlation with their histopathology. Recognizing the radiological findings of various splenic lesions helps narrow down the differential diagnosis and guide appropriate clinical decision-making for radiologists.

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.

Incidental Hemangioma in Tubectomy and Hemorrhoidectomy Specimens: A Report of Two Cases

Benign vascular neoplasms, or hemangiomas, can develop anywhere in the body.As they are usually asymptomatic, they are discovered incidentally while evaluating other coexisting diseases or conditions. We herein report two cases of capillary hemangioma at two extremely rare sites. A woman in her early 30s with a history of nine months of amenorrhea came for safe confinement and underwent an elective lower segment cesarean section (LSCS) with bilateral concurrent tubectomy. Another case involved a man in his 40s who presented with bleeding per rectum for three months. Per rectal examination, two purplish red masses were noted at the 3 and 11 o'clock positions, which were noncompressible and did not bleed on touch. Subsequently, a hemorrhoidectomy was performed. A well-defined vascular lesion in the fallopian tube and hemorrhoidal tissue were seen during the histopathological examination, which was compatible with a capillary hemangioma. The vascular endothelium was emphasized by immunostaining with CD34.Due to the potential for these lesions to manifest as surgical emergencies, it is imperative for surgeons to recognize and appropriately manage such presentations.

Hepatomegaly and Splenomegaly: An Approach to the Diagnosis of Lysosomal Storage Diseases

Clinical findings of hepatomegaly and splenomegaly, the abnormal enlargement of the liver and spleen, respectively, should prompt a broad differential diagnosis that includes metabolic, congestive, neoplastic, infectious, toxic, and inflammatory conditions. Among the metabolic diseases, lysosomal storage diseases (LSDs) are a group of rare and ultrarare conditions with a collective incidence of 1 in 5000 live births. LSDs are caused by genetic variants affecting the lysosomal enzymes, transporters, or integral membrane proteins. As a result, abnormal metabolites accumulate in the organelle, leading to dysfunction. Therapeutic advances, including early diagnosis and disease-targeted management, have improved the life expectancy and quality of life of people affected by certain LSDs. To access these new interventions, LSDs must be considered in patients presenting with hepatomegaly and splenomegaly throughout the lifespan. This review article navigates the diagnostic approach for individuals with hepatosplenomegaly particularly focusing on LSDs. We provide hints in the history, physical exam, laboratories, and imaging that may identify LSDs. Additionally, we discuss molecular testing, arguably the preferred confirmatory test (over biopsy), accompanied by enzymatic testing when feasible.

Incidental Focal Spleen Lesions: Integrated Imaging and Pattern Recognition Approach to the Differential Diagnosis

Spleen lesions and pseudolesions, detected incidentally in imaging, are not uncommon and may require further work-up. The imaging appearance of focal splenic lesions (FSLs) may not be pathognomonic, because of considerably overlapping features. Consequently, all imaging techniques lack specificity to fully characterize FSLs. Clinical correlation is mandatory, so as, first of all, to categorize the patient as having or not having a history of solid or hematologic malignancy. Nowadays, many patients have old imaging studies available for comparison and, consequently, it is important to understand if the lesion was previously present or not, and if the size is the same or has changed. In the absence of comparison studies, and with a lack of imaging features of benignity, further investigation may be necessary, using PET, biopsy, or short-term follow-up. Some algorithms have been proposed to manage incidental FSLs; however, none of these strategies has been validated by prospective studies to date. In this review we illustrate the topic of incidental FSLs and we analyze a number of published algorithms.

The Spectrum of Solitary Benign Splenic Lesions-Imaging Clues for a Noninvasive Diagnosis

Cross-sectional imaging of the upper abdomen, especially if intravenous contrast has been administered, will most likely reveal any acute or chronic disease harbored in the spleen. Unless imaging is performed with the specific purpose of evaluating the spleen or characterizing a known splenic lesion, incidentally discovered splenic lesions pose a small challenge. Solitary benign splenic lesions include cysts, hemangiomas, sclerosing angiomatous nodular transformation (SANT), hamartomas, and abscesses, among others. Sarcoidosis and tuberculosis, although predominantly diffuse micronodular disease processes, may also present as a solitary splenic mass lesion. In addition, infarction and rupture, both traumatic and spontaneous, may take place in the spleen. This review aims to describe the imaging features of the most common benign focal splenic lesions, with emphasis on the imaging findings as these are encountered on routine cross-sectional imaging from a multicenter pool of cases that, coupled with clinical information, can allow a definite diagnosis.

First case report of splenomegaly with splenic infarction due to aortic graft infection

BACKGROUND

Diagnosis of aortic graft infections (AGI) is challenging. Here, we report a case of AGI with splenomegaly and splenic infarction.

CASE PRESENTATION

A 46-year-old man who underwent total arch replacement for Stanford type A acute aortic dissection one year prior presented to our department with fever, night sweat, and a 20-kg weight loss over several months. Contrast-enhanced computed tomography (CT) revealed splenic infarction with splenomegaly, fluid collection, and thrombus around the stent graft. Positron emission tomography-CT (PET-CT) revealed abnormal ¹⁸F-fluorodeoxyglucose uptake in the stent graft and spleen. Transesophageal echocardiography revealed no vegetations. The patient was diagnosed with an AGI and underwent graft replacement. Blood and tissue cultures in the stent graft yielded Enterococcus faecalis. After the surgery, the patient was successfully treated with antibiotics.

CONCLUSIONS

Splenic infarction and splenomegaly are the clinical findings of endocarditis but are rare in graft infection. These findings could be helpful to diagnose graft infections, which is often challenging.

Extramedullary Hematopoiesis: A Forgotten Diagnosis and a Great Mimicker of Malignancy

ABSTRACT

Radiology errors have been reported in up to 30% of cases when patients have abnormal imaging findings. Although more than half of errors are failures to detect critical findings, over 40% of errors are when findings are recognized but the correct diagnosis or interpretation is not made. One common source of error is when imaging findings from one process simulate imaging findings from another process but the correct diagnosis is not made. This can result in additional imaging studies, unnecessary biopsies, or surgery. Extramedullary hematopoiesis is one of those uncommon disease processes that can produce many imaging findings that may lead to misdiagnosis. The objective of this article is to review the common and uncommon imaging features of extramedullary hematopoiesis while presenting a series of interesting relevant illustrative cases with emphasis on CT.

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.

A Practical Perspective of the Hematologic Manifestations of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease with an unknown etiology that can affect any organ or system of the human body. Hematological, renal, or central nervous system manifestations in these patients result in great morbidity because high doses of glucocorticoids, cytotoxic medications, or biological drugs are required to control these manifestations. It is noteworthy that hematological involvement predominates during the first years of the disease and tends to last over time, with the premise that it may be the initial manifestation of the disease. Clear examples of this are the cases of hemolytic anemia and immune thrombocytopenia that can be initially classified as idiopathic or primary to be later classified as secondary when associated with infections, medications, neoplasms, or autoimmune diseases. The spectrum of hematologic manifestations in SLE is very broad, including lymphopenia, anemia, thrombocytopenia, or pancytopenia. In some cases, lymphadenopathy and splenomegaly are also identified. The vast majority of these manifestations denote high disease activity. However, many of these alterations have a multifactorial cause that must be taken into account to adopt a more complete therapeutic approach. The objective of this review is to characterize in detail the hematological manifestations of SLE to offer clinicians a practical vision of its diagnosis and treatment.

MDCT Findings of Splenic Pathology

The delineation and characterization of splenic lesions and other abnormalities can be challenging on computed tomography. Many splenic lesions are incidentally found, imaging features tend to overlap, and without the appropriate clinical context, differentials can range from benign to malignant. Radiologists should be familiar with the wide variety of pathologies seen on computed tomography as it is often the first imaging modality a splenic lesion is seen. The purpose of this MDCT-focused review is to understand normal splenic anatomy and its variants, to illustrate and describe typical and atypical imaging patters of inflammatory, infectious, vascular, traumatic, benign, and malignant tumors of the spleen and provide clues in reaching the appropriate differential diagnosis and management.

Rare case of littoral cell angioma recognised on CT simulation for adjuvant radiation treatment for early stage breast cancer

A 63-year-old woman with pathological anatomic/prognostic stage IA ER+/PR+/HER2- multifocal invasive mammary carcinoma with mixed ductal and lobular features of the left breast underwent lumpectomy with sentinel lymph node biopsy. During evaluation of the CT simulation for adjuvant radiation (RT) treatment planning, a liver lesion and splenomegaly were noted. A subsequent MRI abdomen revealed a large, indeterminate splenic lesion with a wide differential and a benign liver cyst. The patient ultimately underwent splenectomy, with pathology consistent with littoral cell angioma, a rare entity associated with several malignancies. At last follow-up, 7 months after completion of RT, she remained cancer free while on anastrazole and was doing well clinically.

Mesothelial cyst of the spleen mimicking a metastasis: a case report

Mesothelial cyst of the spleen is a developmental disorder. Previous reports have elaborated on the radiological features of splenic mesothelial cysts as being unilocular with a smooth and well-defined margin. However, due to its rarity, it is unclear whether these characteristics are representative and specific for the diagnosis of mesothelial cysts. Herein, this case report presents an atypical case of splenic mesothelial cyst mimicking a malignant tumour, especially splenic metastasis in a 66-year-old woman with ascending colon cancer. Due to an overlapping imaging finding of hypodense splenic lesions, and considering the clinical history, a mesothelial cyst that developed as a multilocular hypodense mass from an ill-defined small nodule was inevitably misdiagnosed as metastasis. Although rare, it is important to consider the possibility of mesothelial cyst in a patient with multilocular hypodense lesions of the spleen.

Huge Non-parasitic Mesothelial Splenic Cyst in a Child: A Case Report and Literature Review

Background:

Splenic cysts are one of the relatively rare conditions in pediatric surgery practice. Primary non-parasitic splenic cysts are even more scarce.

Case presentation:

A 13-years-old female patient presented with chronic left hypochondrial pain of 2 months duration. Abdominal ultrasonography and computed tomography revealed huge 18 cm × 14 cm × 10 cm splenic cyst. Deroofing of the cyst was done which was complicated by secondary infection. Subsequently, the patient was re-operated on and partial splenectomy done with good outcome at 6 months follow up.

Conclusion:

Partial splenectomy is the best management strategy for huge non-parasitic splenic cysts in children. There is also less recurrence rate of splenic cysts with preservation of splenic functions.

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.

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.

Myoid Angioendothelioma of the Spleen - Case Report and Literature Review

Myoid angioendothelioma (MA) represents an extremely rare nonhaematopoietic proliferation of the spleen. MA is a rare, benign, vascular tumour that consists of vascular elements and arranged stromal cells. Due to an absence of specific clinical signs and symptoms, MA is considered challenging to diagnose. Although the radiological presentation can indicate the vascular nature of the tumour, the diagnosis of MA is almost exclusively obtained from the use of histopathology after surgical excision and immunohistochemistry of the tissue. Due to its completely unclear biological behaviour and relationship with other primary and secondary tumours, the only effective therapy for MA is splenectomy and a regular postoperative follow-up. Herein, we report a case of a 26-year-old male patient with nonspecific abdominal pain and a radiologically detected tumour of the spleen who underwent a laparoscopic splenectomy. Histopathologic and immunohistochemical examinations confirmed a myoid angioendothelioma of the spleen.

Calcified Splenic Lesions: Pattern Recognition Approach on CT With Pathologic Correlation

OBJECTIVE. Incidental splenic lesions, often found on CT images of the abdomen, may often be ignored or mischaracterized. Calcified splenic lesions are often presumed to be granulomas; however, understanding the broader differential diagnostic considerations can be useful. CONCLUSION. Determining the cause of splenic lesions is essential to guide appropriate management; the pattern of calcification together with other imaging and clinical findings can aid with differentiation.

Marrow outside marrow: imaging of extramedullary haematopoiesis

Extramedullary haematopoiesis (EMH) refers to the formation of non-neoplastic blood cell lines outside the bone marrow and is a common incidental finding when patients with haematological disorders are imaged. EMH presenting as mass (tumefactive EMH) has long been a radiological conundrum as it resembles neoplasms. Several imaging findings have been described in EMH, and these vary depending on the activity of the underlying haematopoiesis. The older lesions are easier to diagnose as they often demonstrate characteristic findings such as haemosiderin and fat deposition. In comparison, the newer, actively haematopoietic lesions often mimic neoplasms. Molecular imaging, particularly ^99mTc labelled sulphur colloid scintigraphy, may be helpful in such cases. Although imaging is extremely useful in detecting and characterising EMH, imaging alone is often non-diagnostic as no single mass shows all the typical findings. Hence, a judgement based on the clinical background, combination of imaging findings, and slow interval growth may be more appropriate and practical in making the correct diagnosis. In every case, an effort has to be made in providing an imaging-based diagnosis as it may prevent a potentially risky biopsy. When confident differentiation is not possible, biopsy has to be resorted to. This article describes the causes, pathophysiology, and theories underlying the genesis of EMH, followed by the general and location-specific imaging findings. The purpose is to provide a thorough understanding of the condition as well as enable the clinical radiologist in making an imaging-based diagnosis whenever possible and identify the situations where biopsy has to be performed.

Primary lymphomas of the intraabdominal solid organs and the gastrointestinal tract: spectrum of imaging findings with histopathological confirmation

Unlike nodal lymphoma, primary lymphomas of the intraabdominal organs are uncommon neoplasms whose diagnosis may be challenging in certain clinical circumstances. Despite this difficulty for imaging diagnosis, there are several imaging features on ultrasonography, computed tomography, magnetic resonance imaging, and positron emission tomography that may suggest the correct diagnosis. The scope of this review is to describe and illustrate the imaging features of primary lymphoma of intraabdominal organs providing clues to the diagnosis, together with their pathological correlations.

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.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: Lessons from a Rare Case and Review of the Literature

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is an extremely rare benign lesion. We herein report a case of asymptomatic SANT of the spleen in a middle-aged woman with early breast carcinoma and an undiagnosed splenic mass, which was successfully treated by laparoscopic splenectomy and diagnosed postoperatively. We also review the literature on SANT to help make knowledge more accessible when clinicians encounter a splenic tumor. The present case taught us the following lesson: the presence of a splenic lesion during follow-up for malignancy is not always indicative of metastasis. Therefore, SANT should be considered in the differential diagnosis.

Splenic Involvement in Disseminated Mycobacterium avium-intracellulare Infection: Magnetic Resonance Imaging Findings

We report the imaging findings of a patient with disseminated Mycobacterium avium-intracellulare complex presenting with multiple splenic lesions incompletely characterized on computed tomography in whom magnetic resonance imaging helped narrow the differential diagnosis. We discuss the magnetic resonance imaging findings suggesting the diagnosis, including the presence of focal susceptibility artifact within the lesions (ie, signal drop on T1 in-phase imaging), marked hypointensity on diffusion-weighted imaging, and faint progressive peripheral enhancement after contrast administration. We provide pathologic correlation to explain these imaging characteristics and a review of the literature of imaging characteristics in splenic involvement of M. avium-intracellulare complex infection.

Splenic lymphangioma in an adult

Splenic lymphangiomas are exceedingly rare benign neoplasms that occur mainly in children. They are commonly seen in the neck and axillary region. Abdominal lymphangiomas accounts for less than 5% of cases. So far, fewer than 100 cases of spleen lymphangiomas have been reported in the literature. In this paper, we present one case of solitary splenic lymphangioma in a 34-year-old woman who presented with abdominal pain and weight loss for one month. The patient underwent splenectomy and diagnosis was confirmed by histopathology and immunohistochemistry studies. There was no clinical or radiological evidence of diffuse lymphangiomatosis syndrome. This case indicates that splenic lymphangiomas should be considered in the differential diagnosis of splenic cystic masses, even in adults, and should be managed with splenectomy once diagnosed to prevent complications.

Sclerosing angiomatoid nodular transformation of the spleen: A case report and literature review

Sclerosing angiomatoid nodular transformation (SANT) is a rare benign splenic vascular lesion. Since it was first defined in 2004, a total of 132 cases of SANT have been reported in ~50 studies in the English literature. However, it remains difficult to form a definitive pre-operative differential diagnosis of SANT compared with other splenic tumors or malignant lesions. The present study reports a pathologically proven case of SANT in a 29-year-old man who initially presented with left upper quadrant and back discomfort. The study also provides a review of the current knowledge on the condition, including the clinical profile, imaging features, cytological features, differential diagnosis and treatment of SANT. The most important distinguishing features of SANT are its typical vascular character and lack of other features that are typical of a granuloma. A splenectomy is required and the diagnosis is based on pathological analysis.

Imaging findings of splenic emergencies: a pictorial review

Although traumatic injuries are the cause of common splenic emergencies in the emergency room, various nontraumatic conditions may also affect the spleen with possible life-threatening results. In this pictorial review, we present imaging findings of usual and unusual splenic emergencies. It is essential to be familiar with key imaging findings and advantages of different modalities to reach a definitive diagnosis.

TEACHING POINTS

• Delayed splenic rupture is commonly related to subcapsular hematoma. • Subtle haemorrhage is commonly restricted to the site of injury "sentinel clot sign". • The whorled appearance is the key imaging feature of splenic torsion.

An uncommon presentation of metastatic melanoma: a case report

Metastases to the spleen are rare and are generally part of a multi-visceral metastatic disease. The most common sources of splenic metastases include breast, lung and colorectal malignancies as well as melanoma and ovarian carcinoma. Solitary splenic metastasis is very uncommon. We present a case of a 44-year-old man who presented at our department for gallstones symptoms. He had a past medical history of neck cutaneous melanoma (T3bN0M0--Stage IIb). He had not attended follow-up schedule for personal reasons. However, abdominal ultrasound revealed the presence of a solitary solid lesion in the spleen. Preoperative workup was completed with CT scan that confirmed the presence of a large splenic lesion with subcapsular fluid collection, also compatible with a post-traumatic lesion.Preoperative findings could not exclude malignancy and patient was therefore submitted to surgery. At laparoscopy, a condition of peritoneal melanosis was present. Splenectomy was carried out. Histological report confirmed the peritoneal melanosis and the diagnosis of metastatic spleen lesion from melanoma. Patient was observed, but died of metastatic disease 14 months after surgery. Splenic metastases are uncommon. Isolated metastases from melanoma are rare and could be found several months after primary diagnosis of melanoma. Surgery remains the most effective treatment, especially for metachronous disease, offering the best chance of long-term survival. Prognosis remains poor, as metachronous disease is indicative of aggressive widespread of the disease.