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Pe d i a t r i c I m a g i n g • O r i g i n a l R e s e a r c h Dhyani et al. Imaging Noncystic Splenic Lesions Downloaded from www.ajronline.org by Countway Library Of Medicine on 11/25/13 from IP address 128.103.149.52. Copyright ARRS. For personal use only; all rights reserved Pediatric Imaging Original Research Defining an Imaging Algorithm for Noncystic Splenic Lesions Identified in Young Patients Manish Dhyani1 Sudha A. Anupindi2 Rama Ayyala3 Peter F. Hahn1 Michael S. Gee1 Dhyani M, Anupindi SA, Ayyala R, Hahn PF, Gee MS Keywords: algorithm, computed tomography, malignancy, MRI, non-cystic, pediatric imaging, spleen, splenic lesion, ultrasound, young adults DOI:10.2214/AJR.12.10105 Received October 10, 2012; accepted after revision March 5, 2013. 1 Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Ellison 237, Boston, MA 02114. Address correspondence to M. S. Gee ([email protected]). 2 Department of Radiology, Children’s Hospital of Philadelphia, University of Pennsylvania Perleman School of Medicine, Philadelphia, PA. 3 Department of Radiology, Columbia Presbyterian Medical Center, Columbia University School of Medicine, New York, NY. WEB This is a web exclusive article. AJR 2013; 201:W893–W899 0361–803X/13/2016–W893 © American Roentgen Ray Society OBJECTIVE. The purpose of this study was to classify noncystic splenic lesions detected on imaging in young patients (0–30 years) and to determine the optimal imaging workup for such lesions. MATERIALS AND METHODS. This study was conducted at three academic institutions by performing a database search of radiology reports (2002–2011) to identify patients with noncystic splenic lesions. Medical records were then searched to identify radiology examination indications, clinical follow-up, and lesion changes on subsequent imaging. All lesions had either definitive diagnosis (histopathology or laboratory results consistent with infectious cause) or lesion stability more than 2 years consistent with a benign cause. RESULTS. Benign (n = 32), benign indeterminate (n = 7), and malignant (n = 14) lesions were identified in 53 patients (26 males and 27 females; mean age, 19 years; age range, 1 month–30 years). Lesions were initially detected on the following imaging modalities: CT (n = 27), ultrasound (n = 12), MRI (n = 6), and PET/CT (n = 8). A total of 14 patients underwent MRI for lesion characterization, and 12 underwent PET/CT. MRI permitted definitive characterization of benign lesions in 10 of 14 (72%) patients, whereas PET/CT was used to diagnose nine of nine (100%) malignant splenic lesions and helped exclude malignancy in two of three benign lesions. CONCLUSION. Contrast-enhanced MRI is recommended for imaging workup of noncystic splenic lesions discovered in young patients because it can enable definitive diagnosis of most benign lesions. Lesions with indeterminate MRI features can be followed-up with ultrasound or CT. PET or PET/CT is recommended for patients with clinical evidence of malignancy but is less helpful for characterization of isolated splenic lesions. D espite its important role in the immune system, the spleen is often referred to as the forgotten organ [1]. Solitary focal lesions of the spleen are relatively rare and hence tend to be overlooked on imaging examinations [2]. This low incidence of focal abnormality within the spleen may be attributed to the high concentration of splenic immune effector cells that provide a good defense against infectious organisms and tumor infiltration. Despite these barriers, a diverse range of lesions involve the spleen, including congenital, infectious, inflammatory, traumatic, vascular, and neoplastic causes [3]. Simple cysts of the spleen can be easily diagnosed. However, despite advances in imaging technology that have led to increased conspicuity of splenic lesions, it remains difficult to distinguish benign from malignant noncystic splenic lesions on the basis of imaging characteristics. Most splenic lesions detected are incidental findings on abdominal imaging examinations performed for nonspleen-related clinical indications and are commonly referred to as “incidentalomas” [1]. Such incidentally discovered splenic lesions are frequently diagnosed, particularly in the emergency department setting where CT of the abdomen and pelvis is often performed to evaluate patients with abdominal pain or a history of blunt abdominal trauma. Additionally, the rise in abdominal ultrasound use for imaging evaluation of symptomatic young patients will likely contribute to this increase. Such incidentally found lesions represent a clinical dilemma regarding management, and in the absence of a conclusive radiologic diagnosis, histopathologic evaluation by either percutaneous splenic biopsy or splenectomy may be required [4]. The management of splenic lesions found in the young patient population (0–30 years) AJR:201, December 2013W893 Downloaded from www.ajronline.org by Countway Library Of Medicine on 11/25/13 from IP address 128.103.149.52. Copyright ARRS. For personal use only; all rights reserved Dhyani et al. A B Fig. 1—7-year-old girl with echinococcal cysts in spleen. Sagittal ultrasound image shows cystic structure with distinct internal undulating membranes. Red and blue pixels signify areas of minimal internal Doppler vascularity. Fig. 2—11-year-old girl with diffuse lymphangiomatosis. A, Coronal T1-weighted image shows multiple lesions low in signal intensity in enlarged spleen (white arrows). In addition patient has ascites (black arrow). B, Coronal T2-weighted image shows bright lesions in spleen (white arrows) and bones (black arrow). is a particular diagnostic dilemma because of the relatively low rates of invasive cancer and cancer-related death in young patients compared with the older patient population [5]. The decision whether to seek a histologic diagnosis for a splenic incidentaloma that is most likely benign is difficult given the low, but not zero, complication and morbidity rates associated with splenic biopsy [6, 7] or splenectomy [8]. This highlights the need to investigate the role of different imaging modalities in characterization of noncystic splenic lesions. The purpose of our study was therefore twofold. The first goal was to determine the causes of incidentally discovered splenic lesions in young patients on the basis of a relatively large number of patients from three academic medical centers that see a high volume of pediatric and young adult patients. The second goal was to derive a practical imaging algorithm for evaluation of incidentally discovered splenic lesions in the 0- to 30-year-old age group. matic splenic lacerations were excluded. Nonsimple cysts were included because they can arise from infection or necrotic tumor. In addition, lesions that did not have a histologic diagnosis or meet the criteria for diagnosis as a “benign indeterminate” lesion (defined later) were excluded. Fifty-three patients were identified within the age group of 0–30 years with focal splenic lesions detected using ultrasound, CT, MRI, or PET. We reviewed the medical records of all 53 patients. The following were noted in a detailed data acquisition chart: initial mode of scanning at which splenic lesions were first seen, age at initial scanning, reason for imaging, and subsequent follow-up. Medical and surgical records were then reviewed along with histology and laboratory results. The final diagnosis of each lesion was re- corded on the basis of the histopathology report from either splenic biopsy or surgical splenectomy. Lesions without a definitive histopathologic diagnosis were included in the study and assigned a diagnosis of “benign indeterminate” if they showed stable appearance on subsequent imaging examinations performed at least 2 years after the date of the initial imaging examination that documented the presence of the lesion. The reasons for initial scanning of the patient were grouped under the following categories: trauma workup, when imaging was performed in the emergent setting as part of the trauma workup; infectious cause, if medical or surgical notes documented clinical signs of an infection after which imaging was performed to search for an infectious source; abdominal condition, all lesions that were detected on imaging performed for symptoms and signs of abdominal pain or hepatosplenomegaly and workup A B Data Collection Materials and Methods After institutional review board approval, which waived informed patient or parent consent, a retrospective review of radiology reports was performed at three tertiary care centers (one dedicated pediatric hospital and two large tertiary care centers). Radiology databases were searched for keywords, such as “splenic lesion,” “splenic mass,” and “splenic focus,” for a period between 2002 and 2011. Only patients under the age of 30 years at the time of detection of the lesion were included in the study. Lesions consistent with simple cysts or trau- W894 Fig. 3—5-year-old girl with surgically proven splenic lymphangioma. A and B, Contrast-enhanced axial (A) and early delayed (B) CT images of focal complex low-attenuation mass (arrow) show minimal enhancement, AJR:201, December 2013 Downloaded from www.ajronline.org by Countway Library Of Medicine on 11/25/13 from IP address 128.103.149.52. Copyright ARRS. For personal use only; all rights reserved Imaging Noncystic Splenic Lesions for abnormal laboratory values (elevated liver function tests, neutropenia, positive d-dimer); lymphangiomatosis, three patients with lymphangiomatosis were grouped under this category; evaluation of malignant disease, lesions detected on staging examinations performed for evaluation of malignant disease were categorized in this group. Analysis A B Fig. 4—11-year-old boy who presented with splenomegaly. A, Contrast-enhanced coronal HASTE T2-weighted image without fat saturation shows marked enlargement of spleen with multiple high-signal-intensity lesions within spleen (arrows). B, Contrast-enhanced coronal gradient-echo image shows flow voids in some lesions (arrows), consistent with multiple hemangiomas. A B Fig. 5—24-year-old man with lesion in spleen. A and B, Coronal (A) and axial (B) contrast-enhanced MR images show large lesion in spleen (white arrow) and smaller lesions in liver (black arrows), consistent with metastases (bronchoalveolar epithelioid hemangioendothelioma). Fig. 6—30-year-old woman with breast angiosarcoma. Axial contrast-enhanced CT image shows right hepatic liver lobe with heterogeneous mass (arrow) and smaller lesion in spleen, consistent with metastases. All lesions were categorized as benign, benign indeterminate, or malignant. Benign and malignant lesions were categorized on the basis of histopathology and definitive diagnosis on MRI with IV contrast administration or PET. For benign lesions, histopathology, if acquired, was considered diagnostic and imaging features diagnostic of a specific benign condition were reassuring, with a minimum of 6 months of follow-up qualifying as a benign categorization. Benign indeterminate lesions were categorized on the basis of stability shown by serial follow-up imaging for 2 years. Lesions that were stable but were not characterized on the basis of imaging features and lacked 2-year follow-up were excluded from the study. All malignant lesions had biopsy-proven histopathology of the primary lesion, and imaging follow-up of the splenic lesion confirmed the characteristics of a malignant cause. All images were reviewed by three of the authors, who have more than 5 years of experience in pediatric abdominal imaging. The imaging examinations performed for the patients were associated with the final diagnoses to assess the utility of each of the imaging modalities. Results There were a total of 53 patients (26 males and 27 females) with a mean age of 19 years (age range, 1 month–30 years) identified with focal splenic lesions. A total of 39 benign lesions were identified (16 males and 23 females; mean age, 18 years; age range, 1 month–30 years) (Figs. 1–4). We had a total of 14 malignant lesions (10 males and four females; mean age, 24 years; age range, 17– 30 years) (Figs. 5 and 6). All splenic lesions that were evaluated under the three categories; benign (n = 32), benign indeterminate (n = 7), and malignant (n = 14) are listed in Table 1. The number of imaging examinations performed for the diagnosis of each type of lesion were evaluated: benign (22 ultrasound, 33 CT, 18 MRI, one PET), benign indeterminate (6 ultrasound, 16 CT, one MRI, four PET), and malignant (17 CT, two MRI, and 14 PET). The initial modality on which each lesion was seen and the reason the imaging was per- AJR:201, December 2013W895 Dhyani et al. Downloaded from www.ajronline.org by Countway Library Of Medicine on 11/25/13 from IP address 128.103.149.52. Copyright ARRS. For personal use only; all rights reserved TABLE 1: Splenic Lesions and Diagnostic Workup Diagnostic Workup Patient No. Lesions Ultrasound CT MRI PET 1 2 1 Benign 1 SANT 1 2 Littoral cell — 1 1 — 3 Lymphangiomatosis 1 — 1 — 4 Lymphangiomatosis 1 — 1 — 5 Lymphangiomatosis 1 — 1 — 6 Lymphangioma 1 1 — — 7 Hamartoma 1 1 — — 8 Hemangioma 1 1 1 — 9 Hemangioma — 1 1 — 10 Hemangioma — 1 — — 11 Hemangioma — 1 1 — 12 Hemangioma 1 — — — 13 Complex cyst 2 1 — — 14 Complex cyst 3 1 — — 15 Complex cyst 2 — 1 — 16 Complex cyst 1 2 1 — 17 Proteinaceous cyst 1 — 1 — 18 Pseudocyst 1 1 — — 19 Infarcts — 2 — — 20 Infarcts — 1 1 — 21 Infarcts — 1 — — 22 Infarcts — 2 1 — 23 Infarcts — 1 — — 24 Bartonella 1 1 1 — 25 Bartonella — 1 1 — 26 Bartonella — 1 — — 27 Echinococcus — 2 — — 28 Echinococcus 1 1 — — 29 Mycobacterium tuberculosis — 3 — — 30 Candida 1 1 — — 31 Splenic abscess — 3 1 — 32 Siderotic nodule 1 — 1 — 6 16 1 4 33–39 Benign Indeterminate Malignant 40–48 Lymphoma — 8 1 14 49 Sarcoma — 2 — — 50 Angiosarcoma (breast) — 1 — — 51 Epithelioid hemangioendothelioma — 1 1 — 52 Teratoma (testis) — 3 — — 53 Seminoma (testis) — 2 — — 28 66 21 19 Total Note—SANT = sclerosing angiomatoid nodular transformation. Dash indicates not applicable. W896 formed are tabulated in Table 2. Excluding lesions found in patients undergoing followup of malignancy, splenic lesions were most commonly seen when patients were evaluated for trauma (14/38, 36.8%), with a majority (13/14) benign or benign indeterminate. For benign and benign indeterminate lesions, incidental splenic lesions were most commonly seen when the patient was being evaluated for trauma (13/39, 33%) and abdominal pain (13/39, 33%). Malignant lesions of the spleen were most commonly seen during evaluation of a known malignancy (13/14, 93%), with only one of 14 (7%) diagnosed in a patient without a known history of malignancy. For 13 patients being evaluated for abdominal pain, ultrasound was the initial imaging modality in six of 13, five of 13 with CT, and two of 13 with MRI. CT was the most common initial imaging modality used for evaluating patients for trauma workup (11/13) and infection (6/8). MRI was the first imaging modality for patients with an abnormal physical examination (2/3), whereas PET/CT was the initial imaging modality used in evaluating patients with known malignant disease (8/15). Most lesions identified on imaging performed for trauma patients (13/14) were benign (93%), except in one patient in whom an incidental finding on CT led to the diagnosis of diffuse large B cell lymphoma. On the other hand, only two of 15 (13%) lesions on follow-up imaging for known malignant disease were benign. For imaging performed in patients without a known history of malignancy (n = 38) (i.e., imaging performed for trauma workup, infectious cause, abdominal condition, and lymphangiomatosis), only one of 38 (2.6%) resulted in a malignant finding. The basis of diagnosis of all benign and benign indeterminate lesions is tabulated in Table 3. MRI was performed in 14 of 39 patients and was diagnostic in 10 (71%). Of the four patients (sclerosing angiomatoid nodular transformation [SANT], littoral cell angioma, Bartonella infection, and benign indeterminate) with nondiagnostic MRI, two underwent subsequent PET (SANT and Bartonella infection). For the patient with Bartonella infection, the diagnosis was established by positive serology correlation and response to treatment on subsequent imaging for a definitive diagnosis. The littoral cell angioma was nondiagnostic on biopsy and the patient underwent splenectomy for definitive diagnosis. Overall, PET was performed for three benign lesions (8%), and a negative AJR:201, December 2013 Imaging Noncystic Splenic Lesions TABLE 2: Reason for Imaging, Initial Imaging Modality Used, and Final Diagnosis Downloaded from www.ajronline.org by Countway Library Of Medicine on 11/25/13 from IP address 128.103.149.52. Copyright ARRS. For personal use only; all rights reserved Initial Modality Reason for Imaging Ultrasound CT Final Diagnosis MRI PET Benign Benign Indeterminate Malignant Total Trauma workup 2 11 1 — 11 2 1 14 Infectious cause 2 6 — — 8 — — 8 Abdominal condition 6 5 2 — 10 3 — 13 Lymphangiomatosis 1 — 2 — 3 — — 3 Evaluation of malignant disease 1 5 1 8 — 2 13 15 Total 12 27 6 8 32 7 14 53 Note—Dash indicates not applicable. TABLE 3: MRI and PET for Benign and Benign Indeterminate Lesions MRI Final Diagnosis No. PET No. Diagnosis No. FDG Uptake Basis of Diagnosis Infectious Bartonella 3 1 Not conclusive — — 2 Histopathology (liver biopsy) and 1 treatment response Echinococcus 2 — — — — Imaging and clinical correlation Candida 1 — — — — Clinical correlation Mycobacterium tuberculosis 1 — — — — Histopathology (autopsy) Abscess 1 — — — — Clinical correlation Benign indeterminate 7 1 Not conclusive 2 No Follow-up imaging Hemangioma 5 3 Conclusive — — 3 MRI, histopathology (autopsy), histopathology (splenectomy) Pseudocyst 1 — — — — CT Lymphangiomatosis 3 3 Conclusive — — MRI Proteinaceous cyst 1 1 Conclusive — — MRI Siderotic nodule 1 1 Conclusive — — MRI Infarct 5 1 Conclusive — — 4 CT, 1 MRI Complex cyst 4 1 Conclusive — — 2 Histopathology (biopsy), 1 MRI, 1 histopathology (splenectomy) Littoral cell angioma 1 1 Not conclusive — — Histopathology (splenectomy) Hamartoma 1 — — — — Histopathology (splenectomy) Lymphangioma 1 — — — — Histopathology (splenectomy) SANT 1 1 Not conclusive 1 Yes Histopathology (splenectomy) Note—SANT = sclerosing angiomatoid nodular transformation. Dash indicates not applicable. TABLE 4: MRI and PET for Diagnosis of Malignant Lesions MRI Final Diagnosis No. No. Nodular sclerosing type 7 Large B-cell 2 Sarcoma PET Diagnosis No. FDG Basis of Diagnosis — — 7 Uptake Clinical and PET 1 Conclusive 2 Uptake Clinical and PET 1 — — — — Clinical Angiosarcoma (breast) 1 — — — — Clinical Epithelioid hemangioendothelioma 1 1 Conclusive — — Clinical Teratoma (testis) 1 — — — — Clinical Seminoma (testis) 1 — — — — Clinical Lymphoma Metastases Note—Dash indicates not applicable. AJR:201, December 2013W897 Dhyani et al. Downloaded from www.ajronline.org by Countway Library Of Medicine on 11/25/13 from IP address 128.103.149.52. Copyright ARRS. For personal use only; all rights reserved Noncystic splenic lesion No known malignancy History of malignancy Not FDG avid MRI Definitely benign (Hemangioma, lymphangioma, etc.) PET or PET/CT Indeterminate MRI FDG avid Follow-up imaging (Ultrasound or CT) (Ultrasound preferred if lesion is visible) Consider histological sampling Workup for malignancy Fig. 7—Flowchart shows proposed algorithm for follow-up of splenic lesions. PET provided reassurance against malignant disease in two (67%) patients. Both patients were subsequently followed up for more than 2 years with stability of lesion and were categorized as benign indeterminate. A positive PET result for one lesion resulted in subsequent splenectomy and diagnosis of SANT on histopathology. Negative PET results and stability of splenic lesion for more than 2 years helped exclude malignant disease in two patients being evaluated for Hodgkin lymphoma and gallbladder carcinoma. Histopathology without MRI, was acquired by biopsy (n = 2) and surgery (n = 4) in a total of six noninfectious benign lesions. Table 4 summarizes the utility of MRI and PET in the determination of malignant splenic lesions. PET was performed in 10 of 14 patients and showed 18F-FDG-avidity in 100% of patients. Discussion To our knowledge, an imaging algorithm for incidentally discovered splenic lesions in young patients has not been established. This is in part because no comprehensive review of splenic lesions in young patients with a known diagnosis has yet been performed. We suspect that most splenic lesions detected on imaging would be benign, given the lower baseline incidence of overall malignancy in young people relative to older adults [9]. Our study of three large academic centers, including one dedicated pediatric hospital and two large tertiary care referral centers, revealed a total of 53 splenic lesions detected in young patients on imaging, with 39 benign and 14 malignant lesions for a 74% rate of benignity. Thirteen of the 14 malignant lesions were identi- W898 fied on imaging examinations of patients with a known history of extrasplenic malignancy. When these patients are excluded, the rate of benign lesions rises to 97% (38/39) in young patients. To our knowledge, this represents the largest report of imaged splenic lesions in young patients to date. Having established the reason for imaging and imaging modality that led to detection of the splenic lesions in our patients, we then examined the follow-up imaging performed on each lesion to determine the utility of different imaging modalities on the basis of their ability to aid the radiologist in characterizing splenic lesions and offering a definitive diagnosis. One unique feature of young patients relative to older adults is that ultrasound is used more frequently as the primary imaging modality because of concerns about the ionizing radiation exposure associated with CT [10–12]. In our series, ultrasound was the most common initial imaging modality for detecting splenic lesions in patients imaged for abdominal conditions (6/13, 46%). However, CT was the primary initial imaging modality in patients with a history of trauma, infection, or malignancy (22/37, 59%). CT and ultrasound were both useful for the detection of splenic lesions and for distinguishing cystic from noncystic lesions. However, in our series neither modality was considered sufficient to yield a definitive diagnosis of a noncystic splenic lesion on the basis of the initial imaging. In the case of CT, the initial diagnostic examinations performed were single portal venous phase examinations used for routine abdominal evaluation and lacked the arterial and delayed phase images that would be more sensitive for the diagnosis of certain benign splenic lesions, particularly proteinaceous cysts and hemangiomas. In the case of ultrasound, certain sonographic features were suggestive of benign proteinaceous cysts, echinococcal disease (Fig. 1), or hemangioma (hyperechogenicity, increased posterior acoustic enhancement, internal septations), but follow-up imaging was still recommended to increase diagnostic certainty. MRI proved to be a useful imaging modality for the diagnosis of benign splenic lesions (i.e., hemangioma, siderotic nodules, lymphangiomas, proteinaceous or hemorrhagic cysts, and infarcts) (Figs. 2–4). MRI was performed in 14 benign splenic lesions and was diagnostic in 10 (71%). The combination of T2-weighted, gradient-echo, and multiphase contrast-enhanced imaging provides superior lesion characterization compared with CT or ultrasound. We believe that MRI should be performed for all incidentally detected splenic lesions because of its ability to aid the radiologist in making a definitive diagnosis for a number of benign entities. PET was a helpful imaging modality for evaluating splenic lesions in patients with a history of malignancy, aiding a 100% accurate evaluation of splenic lesions in this population. The majority of malignant splenic lesions (9/14, 64%) were foci of lymphoma in patients with a history of lymphoma. In contrast, the incidence of splenic metastases was very low in young patients without a history of malignancy (1/38, 2.6%). The current literature for adults estimates the incidence of nonlymphomatous splenic metastases at 1%, with the most common primary sites being lung (21%), stomach (16%), pancreas (12%), liver (9%), and colon (9%) [3]. In our study population, PET was performed for three splenic lesions in patients without a history of malignancy. All three lesions were benign, with one lesion showing FDG avidity on PET that led to splenectomy and the diagnosis of benign SANT. PET helped classify one lesion as benign in a patient with known Hodgkin lymphoma, resulting in a 7% (1/15) rate of benign disease in patients with a known history of malignancy. Our results suggest that PET is indicated for splenic lesion evaluation in patients with a history of malignancy because of the relatively high risk of metastases. In contrast, in patients with no history of malignancy, our data do not support routine PET evaluation of splenic lesions due to the low baseline risk of splenic metastases and the potential for false-posi- AJR:201, December 2013 Downloaded from www.ajronline.org by Countway Library Of Medicine on 11/25/13 from IP address 128.103.149.52. Copyright ARRS. For personal use only; all rights reserved Imaging Noncystic Splenic Lesions tive FDG uptake by benign splenic lesions, including hamartoma [13] and SANT [14]. A potential imaging algorithm (Fig. 7) for young patients with incidentally discovered splenic lesions includes MRI with IV contrast administration, which could provide definitive imaging diagnosis of some benign lesions. For lesions that are not clearly benign, the next step will vary depending on whether the patient has a known history of malignancy. In patients with a history of malignancy, PET or PET/CT can be helpful to exclude FDG avidity suggestive of malignancy. In young patients with no history of malignancy, an MRI-indeterminate lesion is most likely benign. Management options we suggest from our experience include serial imaging and biopsy (particularly if the patient is symptomatic). Serial imaging should be performed using ultrasound if a lesion is readily distinguished and measured sonographically; otherwise, MR or CT should be considered. There are limitations of our study. This was a retrospective review of medical records and some patients may have been missed. In addition, only patients who were referred for imaging examinations were included in our cohort, and they may not be truly representative of the young population at large. However, this is the population that forms the basis of our imaging algorithm. Also, histopathology was not available for some of the benign lesions in our study; however, diagnosis by characteristic imaging features or stability over time is widely accepted as a surrogate for histology for these lesions. The small number of patients in our study, albeit relatively large compared with those in the reported literature, precludes rigorous statistical analysis and limits our evaluation of the results. Finally, all of the institutions that participated in this study are located in a similar geographic area (northeastern United States); the endemic population of this area may have its own bias with respect to infectious and demographic variation. Conclusion Splenic lesions are uncommon and pose a dilemma for the radiologist and clinician. To our knowledge, this is the largest imaging presentation of splenic lesions in the 0–30-yearold population. Our data show that most of these noncystic splenic lesions are benign, and in many cases contrast-enhanced MRI can provide reassurance. We provide a potential imaging algorithm to demystify these problematic lesions in the “forgotten organ” and provide a path of management to reduce the need for invasive procedures in young patients. 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