Characterization of CT and MRI findings in sclerosing angiomatoid nodular transformation of the spleen: novel discovery of peritumoral vascular signs

Introduction

Sclerosing angiomatoid nodular transformation (SANT) of the spleen was first described in 2004 by Martel et al., who identified its distinctive histological and immunohistochemical characteristics (1). The histological features of SANT, as reflected in its name, include multiple angiomatoid nodules, encased in dense fibrous tissue and a central fibrous scar. Martel et al. classified it as a non-neoplastic, vascular proliferative lesion of the spleen. Previously referred to as multiple nodular hemangioma or splenic cord capillary hemangioma, SANT was once considered a variant of splenic hamartoma. However, the 5th edition of the World Health Organization (WHO) Classification of Tumors of Hematopoietic and Lymphoid Tissues (2022), reclassified splenic-specific vascular-stromal tumors into three categories: littoral cell angioma, splenic hamartoma, and splenic SANT (2).

Splenic SANT is a rare condition with a low incidence rate and is frequently misdiagnosed as a malignancy due to its limited recognition. Clinical observations indicate that most splenic SANT lesions are encircled and penetrated by branches of the splenic artery. Despite these observations, there is a notable lack of reports, both in China and internationally, addressing the diagnostic significance of these findings. In this study, data from 57 individuals with splenic SANT confirmed via surgical pathology were collected. Common imaging characteristics on computed tomography (CT) and magnetic resonance imaging (MRI) were analyzed to deepen the understanding of splenic SANT and to enhance the accuracy of medical imaging-based diagnosis. We present this article in accordance with the STROBE reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2888/rc).

Methods

Basic data

A retrospective analysis was conducted on all consecutive patients diagnosed with splenic SANT through surgical pathology at The First Affiliated Hospital, Zhejiang University School of Medicine and The First Affiliated Hospital of Xinxiang Medical University between January 2010 and December 2023. Among all identified cases, one case was excluded due to the availability of only non-contrast CT images, resulting in 57 consecutive cases with complete imaging data included in the final analysis.

The inclusion criteria were as follows: individuals diagnosed with splenic SANT based on surgical pathology; individuals who underwent preoperative CT or both non-contrast and contrast-enhanced MRI scans; and individuals who had not received any relevant treatment prior to undergoing imaging examinations. This study was a retrospective analysis of ALL consecutive patients with surgically confirmed SANT who had complete imaging data, with no selection bias based on lesion size or imaging characteristics.

The exclusion criteria were as follows: individuals with missing clinical or pathological data and individuals with poor-quality medical images that hindered observation.

This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study was conducted with approval from the Ethics Committee of The First Affiliated Hospital of Xinxiang Medical University (No. EC-024-525). The First Affiliated Hospital, Zhejiang University School of Medicine served as collaborating institutions that provided anonymized imaging data under inter-institutional data sharing agreements. All patient data from The First Affiliated Hospital, Zhejiang University School of Medicine and The First Affiliated Hospital of Xinxiang Medical University have been completely anonymized with removal of all identifying information. Written informed consent was obtained from all participants.

The electronic medical record databases of two hospitals were reviewed for the period from January 1, 2010 to December 1, 2023. A total of 57 consecutive cases, confirmed as splenic SANT through pathology analysis of resected lesions, were ultimately included in this study (one case was excluded due to incomplete imaging data) (Figure 1).

Figure 1 Patient enrollment flow diagram. The diagram shows the systematic screening of all consecutive patients diagnosed with splenic SANT through surgical pathology at both participating hospitals between January 2010 and December 2023. From the initial identification of 58 cases, one case was excluded due to incomplete imaging data (only non-contrast CT available). This resulted in 57 consecutive cases included in the final analysis: 41 cases with contrast-enhanced CT, 34 cases with contrast-enhanced MRI, and 18 cases with both contrast-enhanced CT and MRI. CT, computed tomography; MRI, magnetic resonance imaging; SANT, sclerosing angiomatoid nodular transformation.

Table 1 presents the demographic data of the 57 splenic SANT cases: the cohort comprised 32 males and 25 females, with a mean age of 44.4±15 years [standard deviation (SD)] and a median age of 43 years, and an age range of 20 to 75 years.

The distribution of medical imaging modalities among the 57 individuals was as follows: 41 underwent non-contrast CT and enhanced examinations, 34 underwent non-contrast MRI and enhanced examinations, and 18 underwent both modalities. Complete medical imaging data were available for all 57 cases. Splenic SANT was incidentally detected in 49 individuals during routine health checkups, identified in 6 individuals presenting with abdominal pain and distension, and discovered in 2 individuals during preoperative evaluation for rectal cancer and follow-up after pancreatic neuroendocrine tumor surgery. Among the 57 individuals, 5 individuals had coexisting malignancies, including papillary thyroid carcinoma, colon cancer, rectal cancer, pancreatic neuroendocrine tumor, and liver cancer. Follow-up was conducted through routine hospital visits or telephone interviews.

CT and MRI examination methods

CT scans were conducted using a GE Bright Speed Pro 16-slice spiral CT and a 256-slice Brilliance iCT scanner. The scanning parameters included a tube voltage of 125 kVp, a tube current of 320 mAs, a pitch of 1.0, a slice thickness ranging from 2 to 5 mm, and a 2 mm interslice gap. Iohexol was used as the intravenous contrast agent, administered at a dosage of 1.5 mL/kg and a flow rate of 3.0 mL/s. Delayed scans were performed during the arterial phase (25 to 30 seconds), portal venous phase (60 to 65 seconds), and delayed phase (120 to 140 seconds).

MRI scans were performed utilizing a GE Signal HDxt 3.0T MR scanner. Dynamic contrast-enhanced imaging employed a liver acceleration volume acquisition (LAVA) sequence with the following parameters: 320×256 matrix, 3.3 ms repetition time (TR), 1.5 ms echo time (TE), 10° flip angle, and 5 mm slice thickness. Gadopentetate meglumine was administered intravenously as a contrast agent at a rate of 2.0 to 3.0 mL/s, with a dosage of 0.1 mmol/kg. Multiple-phase scans were acquired at 15 to 20 seconds, 40 to 55 seconds, 140 to 180 seconds, and 300 to 360 seconds post-injection.

Image analysis

All CT and MR images were transferred to the Picture Archiving and Communication System (PACS) workstation of ZuoBiao Co., Ltd. Inc. (Shenzhen ZuoBiao Software Group Co., Ltd. Inc., China) for subsequent analysis. Two experienced physicians specializing in thoracic and abdominal imaging independently analyzed the imaging characteristics of the lesions. Key parameters assessed included the number, size, shape, margin, density, signal intensity, hemosiderin deposition, enhancement pattern, and peritumoral vascular signs. Enhancement patterns were categorized into progressive centripetal enhancement, spoke-wheel centripetal enhancement, and nodular centripetal enhancement. Additionally, the density or signal intensity of the central stellate scar within the lesion was also documented.

Peritumoral vascular signs were categorized into two types: presence of peritumoral vascularity and peritumoral vascularity with a ball-holding appearance. Peritumoral vascularity refers to one or two branches of the splenic artery at the tumor margin being compressed, displaced, and encircling or penetrating the tumor. Peritumoral vascularity with a ball-holding appearance refers to three or more splenic artery branches at the tumor margin being compressed, displaced, and encircling or penetrating the tumor.

Pathological methods

Surgical specimens were processed according to standard histopathological procedures. Tissues were fixed, dehydrated, embedded in paraffin, sectioned, and stained with hematoxylin and eosin (H&E). Immunohistochemistry (EnVision) was performed for further observation under a light microscope.

Statistical analysis

Clinical data were analyzed utilizing SPSS 27.0. Quantitative data were assessed for normality utilizing probability-probability (P-P) plots and quantile-quantile plot (Q-Q) plots. Normally distributed data are presented as mean ± standard deviation, with inter-group comparisons performed utilizing t-tests or one-way analysis of variance (ANOVA). Non-normally distributed data are presented as median (interquartile range) and analyzed utilizing a nonparametric test (Mann-Whitney U test). Qualitative data are presented as frequencies, proportions, and percentages, with inter-group comparisons performed utilizing the Chi-squared test. Statistical significance was defined as P<0.05.

Results

Clinical manifestations

Table 1 presents the clinical manifestations of the 57 individuals diagnosed with splenic SANT. The cohort comprised 32 males and 25 females, yielding a male-to-female ratio of 1.3:1. Ages ranged from 20 to 75 years, with a mean age of 44.4±15 years. Splenic SANT was incidentally identified in 51 asymptomatic individuals during routine physical examinations or preoperative evaluations for other conditions. Only 6 cases presented with symptoms (abdominal pain, distension, or lumbar pain). The high proportion of asymptomatic cases (89%) suggests that many SANT patients may remain undiagnosed if they do not undergo routine health checkups or imaging studies, highlighting the importance of recognizing characteristic imaging features when SANT is encountered incidentally. Tumor growth was observed during preoperative follow-up in 8 individuals and new splenic lesions were seen in 2 individuals during routine follow-up following surgery for bowel cancer or pancreatic neuroendocrine tumor. All individuals underwent splenectomy, which is the current standard treatment for splenic SANT as reported in the literature. No cases of recurrence or metastasis were observed during a follow-up period ranging from 1 to 120 months.

CT and MRI findings

The CT and MRI findings of the splenic SANT cases are presented in Tables 2,3.

Lesion size and morphology

The lesions in the 57 cases ranged from 0.6 to 11.4 cm in diameter, with a mean diameter of 5.63±2.0 cm. Fifty-four individuals presented with solitary lesions, while 3 had multiple lesions. Among the 3 individuals with multiple lesions, 2 had over 20 lesions ranging from 0.6 to 3.1 cm in diameter and 1 had 2 lesions measuring 5.3 and 11.4 cm, respectively. The diameter distribution among the 57 cases was as follows: 3 cases had lesions between 2 and 3 cm, 32 cases had lesions between 3 and 6 cm, and 22 cases had lesions ≥6 cm.

Interior conditions and enhancement patterns of tumors

The enhancement patterns of the 57 individuals with splenic SANT were categorized into three types: progressive centripetal enhancement, spoke-wheel centripetal enhancement, and nodular centripetal enhancement, as illustrated in Figure 2. These centripetal enhancement patterns were further confirmed by significant differences in CT values between the tumors and the corresponding normal splenic tissue at each phase (P<0.05).

Figure 2 Contrast-enhanced CT cross-sectional images during arterial, portal venous, and delayed phases, respectively, demonstrating (A-C) a spoke-wheel centripetal enhancement pattern, (D-F) a nodular centripetal enhancement pattern, and (G-I) a progressive centripetal enhancement pattern. CT, computed tomography.

Among the 34 individuals who underwent MRI, 1 individual with multiple lesions exhibited high signal intensity on both T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI), along with a nodular centripetal enhancement pattern. The remaining 33 individuals demonstrated similar enhancement patterns on both MRI and CT, categorized as spoke-wheel centripetal enhancement (18 cases), nodular centripetal enhancement (12 cases), and progressive centripetal enhancement (4 cases).

Among the 18 individuals who underwent both CT and contrast-enhanced MRI, 11 cases exhibited consistent enhancement patterns across both modalities. Specifically, 6 cases demonstrated nodular centripetal enhancement, 4 cases showed spoke-wheel centripetal enhancement, and one case displayed progressive centripetal enhancement. The remaining 7 cases exhibited discrepant enhancement patterns. All 7 cases showed progressive centripetal enhancement on CT, while on MRI, 4 of them displayed nodular centripetal enhancement and 3 showed spoke-wheel centripetal enhancement.

Manifestations of peritumoral blood vessels

In the arterial phase of CT and contrast-enhanced MRI, 43 individuals exhibited peritumoral vascularity, 7 showed a ball-holding appearance of peritumoral vascularity, as illustrated in Figure 3, and 7 had no discernible splenic arterial branch shadows.

Figure 3 A 71-year-old male was found to have a splenic mass during a routine physical checkup. (A-D) CT scan findings, during the arterial, portal venous, and delayed phases, respectively. The lesion exhibits a nodular, stuffing enhancement pattern at the margins, with a low-density, non-enhancing area representing old hemorrhage. (E) Three-dimensional reconstruction during arterial phase demonstrates multiple branches of the splenic artery encircling and penetrating the tumor, forming a sign of peritumoral vascularity with a ball-holding appearance. (F) Hematoxylin and eosin (50× magnification) shows nodular structures formed by fibrous tissue proliferation and separation. Irregular capillary networks and splenic sinusoid-like structure are present within nodules, along with surrounding hemorrhagic changes and nodular fibrosis. (G-I) Arterial phase, portal venous phase, and delayed phase of an MRI scan, with an enhancement pattern similar to the CT scans. CT, computed tomography; MRI, magnetic resonance imaging.

Dynamic changes

Among the 57 individuals, 8 exhibited significant growth during preoperative follow-up. All individuals underwent laparoscopic complete or partial splenectomy. No recurrence or metastasis was observed during the 1 to 120-month follow-up period.

Discussion

Clinical characteristics

Splenic SANT is a benign tumor that has gained increasing recognition in recent years. It has a low incidence and primarily occurs in the spleen, though isolated cases have been reported in the adrenal gland and accessory spleen (3,4). The male-to-female ratio in this study was 1.3:1. Previous studies have reported varying gender distributions which may be attributed to sample size limitations (5-8). As more cases are reported, gender-based differences in the incidence of splenic SANT are expected to diminish. While splenic SANT can occur at any age, the majority of cases are typically observed between the ages of 30 and 60 years. In this study, the age of individuals ranged from 20 and 75 years, with a mean of 44.4 years, consistent with previous studies (6-10). Most cases of splenic SANT in this study were incidentally discovered, with no specific clinical manifestations. A minority of patients with splenic SANT experience abdominal pain or discomfort. In this study, only six individuals presented with abdominal pain, abdominal distension, or lumbar pain, consistent with previous studies. Kakisaka et al. reported a case of splenic SANT with concurrent disseminated intravascular coagulation (DIC) and speculated that splenic SANT may contribute to blood coagulation disorders, leading to bleeding, anemia, and venous thrombosis (11). However, none of the individuals in this cohort exhibited DIC symptoms and there is currently insufficient evidence to establish a causal relationship between splenic SANT and blood coagulation disorders.

Clinical significance of asymptomatic presentation

The predominantly asymptomatic nature of SANT (89% in our series) presents a significant diagnostic challenge. Since most SANT patients do not present with symptoms, the diagnosis depends entirely on incidental discovery during routine health checkups or imaging studies performed for other clinical indications. This highlights the critical importance of radiologists’ familiarity with characteristic imaging features to ensure accurate diagnosis and appropriate management when these lesions are encountered incidentally.

Correlation analysis between medical imaging and pathology

Peritumoral vascularity in patients with splenic SANT: Limited information is available in previous studies regarding the condition of peritumoral blood vessels in splenic SANT. Watanabe et al. described a case of splenic SANT where contrast-enhanced ultrasound revealed linear arterial branches of the splenic artery traversing from the periphery to the center of the mass during the early arterial phase (12). In this cohort of 57 individuals, 43 (75%) exhibited signs of peritumoral vascularity, and 7 (12%) exhibited peritumoral vascularity with a ball-holding vascular appearance. These findings may be attributed to the rapid growth of the tumor, fibrous component, and relatively firm texture, along with the splenic artery supplying the tumor. The vascular supply can compress the surrounding splenic parenchyma and splenic artery branches, resulting in the formation of peritumoral vascularity and peritumoral vascularity with a ball-holding appearance. In this study, 95% of lesions had a diameter ≥3 cm, suggesting a correlation between tumor size and the prominence of peritumoral vascularity signs. The detection of these signs can contribute to the accurate and differential diagnosis of splenic SANT. However, further investigation is required to determine the feasibility of interventional embolization as a treatment option.

Solitary splenic SANT lesions typically present as well-circumscribed with smooth or lobulated margins. On non-contrast imaging, they exhibit hypodense or low signal intensity. On T2WI and DWI they demonstrate heterogeneous low signal intensity. The in-phase (IP) signal intensity is lower compared to the out-of-phase (OP). Enhancement patterns of these lesions can be categorized into three types: progressive centripetal enhancement, nodular centripetal enhancement, and spoke-wheel centripetal enhancement.

The following imaging findings were observed:

• Hypodensity/low signal intensity on non-contrast CT scans: this finding is attributed to hemosiderin deposition and the abundant fibrous tissue within the lesion. Pathological analysis confirmed these characteristics, which align with observations in previous studies (8,10).
• Calcification: nine out of the 41 individuals (22%) who underwent CT scans exhibited calcification. While calcification is not a characteristic feature of SANT, its presence may be associated with hyaline degeneration. Two potential mechanisms have been proposed to explain this observation: (i) extensive areas of hyaline degeneration may promote increased calcification; (ii) the morphology of the calcification may correspond to the distribution pattern of hyaline degeneration. This correlation is further supported by relevant pathological literature (10,13).
• Low intensity on T2WI, DWI, and decreased IP relative to OP signal: this characteristic is attributed to the deposition of hemosiderin, a superparamagnetic substance, within the lesion. This finding is considered a characteristic feature of SANT.
• Spoke-wheel sign: this sign refers to the annular enhancement and radiating septa-like enhancement at the lesion margin, representing the enhancement of angiomatoid nodules separated by fibrous scar tissue. First described by Karaosmanoglu et al., the spoke-wheel sign was observed in 32% of the 41 individuals undergoing contrast-enhanced CT and 54% of the 34 individuals undergoing contrast-enhanced MRI in our cohort (14). The presence of this sign is associated with the number of angiomatoid nodules within the lesion. A higher number of nodules results in a more pronounced spoke-wheel sign. This is attributed to the clear visualization of low-signal fibrous components and high-signal angiomatoid nodules on MRI, making MRI particularly advantageous for demonstrating the spoke-wheel sign.
• Stellate sign: this refers to the stellate hypodensity or low-signal non-contrast area within the lesion. The appearance of the central stellate fibrous stroma on T2WI is influenced by its water content. High water content results in high signal intensity on T2WI, while low water content results in low signal intensity. A portion of the stellate fibrous tissue may exhibit a delayed enhancement pattern, likely due to limited blood supply, poor vessel wall permeability to contrast agents, and hindered contrast agent excretion. In 85% of the MRI images analyzed in this study, stellate low signal intensity or high signal intensity signs were observed within lesions during the delayed phase. In contrast, CT scans demonstrated these signs in only 46% of cases, a proportion higher than the 22% reported by Lewis et al. (15). This difference may be attributed to the larger sample size in this study. MRI demonstrated a significantly better ability to visualize fibrous scars compared to CT.
• Density or signal intensity at the delayed phase: at the delayed phase of imaging, 88% of lesions appeared hypodense relative to the spleen, while 12% were isodense to hypodense. In the delayed phase of MRI, 68% of lesions demonstrated mixed high and low signal intensities and 32% showed high signal intensities. This difference likely arises from the longer scanning duration of the delayed phase in MRI (5 to 6 minutes) compared to CT (2 to 3 minutes). The slower blood flow within the angiomatoid nodules allows sufficient time for contrast agent accumulation during MRI, resulting in higher signal intensities. In contrast, the shorter CT delay phase may not permit complete contrast filling, leading to hypodense or isodense to hypodense appearances.
• Splenic SANT: splenic SANT with multiple lesions is rare. Cao et al. reported that multiple lesions account for only 4.7% of cases (16). In this cohort, 3 cases (5%) exhibited multiple lesions, consistent with previous findings. One case with multiple lesions demonstrated distinct imaging features compared to solitary lesions. These features included: homogeneous high signal intensity on DWI, high signal intensity on T2WI, absence of visible low-signal fibrous components, gradual enhancement patterns on contrast-enhanced scans, heterogeneous nodular enhancement in the arterial phase, complete filling of smaller lesions with high signal intensity in the portal venous and delayed phases, and high signal intensity in the majority of the largest lesion with scattered patchy low signal fissures.

Hou et al. proposed that angiomatoid nodules undergo a continuous process of growth, development, and maturation, with growth differences between nodules and surrounding tissues (17). Immature nodules exhibit marked congestion with minimal surrounding stromal fibrosis, while mature nodules show significant surrounding fibrosis. The early heterogeneous nodular enhancement pattern of splenic SANT masses likely reflects the growth pattern and distribution of angiomatoid nodules. High signal intensities observed on T2WI and DWI may be attributed to the relatively small size and immature characteristics of the masses. This observation is supported by their limited fibrotic and hemosiderin content. To date, only 13 cases of splenic SANT with multiple lesions have been reported in English literature. Findings suggest that lesions with smaller diameters are associated with reduced fibrous components. Due to the predominance of angiomatoid nodules, these lesions demonstrate a distinctive nodular stuffing enhancement pattern during imaging.

Growth characteristics

In this cohort of 57 cases, 8 cases exhibited lesion growth during preoperative follow-ups, with some lesions increasing in size by approximately 1 cm annually. In one case, a routine abdominal examination 17 months post-surgery for a pancreatic endocrine tumor revealed a new 1.1 cm splenic nodule, which grew to 3.1 cm over the next 2 years. Preoperative imaging suggested splenic metastasis but postoperative pathology confirmed splenic SANT. This indicates that splenic SANT can exhibit a malignant-like growth pattern, consistent with previous reports (18,19). A retrospective analysis of 230 individuals with splenic SANT by Aziret et al. demonstrated that all individuals underwent splenectomy with no recurrence or metastasis (5). Similarly, in this cohort, all 57 individuals underwent splenectomy with no recurrence or metastasis, confirming the benign nature of this tumor (8,20). Laparoscopic splenectomy is a safe and effective minimally invasive surgical approach.

Comparison of roles of CT and MRI in diagnosing splenic SANT

CT imaging is particularly effective in detecting calcifications within lesions, as well as in identifying peritumoral vascularity and ball-holding vascularity signs. It also enables three-dimensional reconstruction of the splenic artery and branches, providing a comprehensive visualization of the peritumoral vasculature. However, MRI, with its multi-sequence capability, excels in detecting intratumoral fibrous components, hemosiderin deposition, angiomatoid nodules, and spoke-wheel enhancement patterns. In this study, differences in enhancement patterns among 18 individuals undergoing both CT and MRI indicate that MRI is better at visualizing angiomatoid nodules and spoke-wheel enhancement. Additionally, MRI also reveals distinctive diagnostic features, such as heterogeneous low signal intensity on T2WI and DWI and reduced IP signal compared to OP sequences. Combining MRI and CT enhances diagnostic accuracy for splenic SANT.

Differential diagnosis

Differentiating splenic SANT from other splenic lesions is essential for accurate diagnosis and appropriate management. The key distinguishing features of common conditions include: (I) splenic hemangioma: the most prevalent benign splenic tumors, typically exhibit nodular arterial phase enhancement with gradual centripetal filling, appearing isodense or hyperintense in portal venous and delayed phases. Unlike splenic SANT, hemangioma exhibits higher enhancement intensity, lack spoke-wheel sign, and shows no low-signal fibrous components. (II) Splenic angiosarcoma: a large heterogeneous mass often accompanied by calcifications, necrosis, and hemorrhage. Its aggressive nature typically leads to adjacent tissue invasion and metastases (21). (III) Splenic hamartoma: a rare lesion with variable enhancement patterns influenced by its internal composition. In the delayed phase, it exhibits isodense signal intensity, lacks low-signal/hypodense fibrous components, and does not display the spoke-wheel sign, distinguishing it from splenic SANT (22). (IV) Splenic Epstein-Barr virus (EBV)-positive follicular dendritic cell sarcoma: These tumors are encapsulated and display a stuffing enhancement pattern with internal non-enhancing necrotic areas, contrasting the nodular and spoke-wheel enhancement pattern of splenic SANT. Unlike splenic SANT, these lesions lack peritumoral vascularity and the ball-holding appearance, aiding the differentiation (23). (V) Splenic littoral cell angioma: littoral cell angioma often presents as multiple or solitary lesions, with a freckle-like sign on T2WI due to iron deposition and high signal intensity on DWI. It exhibits a progressive enhancement pattern with lesion visibility transitioning from few-many-few during contrast-enhanced scanning. In contrast, splenic SANT with multiple lesions displays nodular enhancement patterns without the freckle-like sign, aiding differentiation (24).

Conclusions

In summary, splenic SANT is a rare benign tumor characterized by a solitary well-circumscribed, non-encapsulated mass without necrosis or cystic changes, though calcifications may occur. On contrast-enhanced imaging, it exhibits nodular centripetal spoke-wheel and persistent enhancement patterns, with hypodense or high signal intensity in delayed phases. A central stellate non-enhancing hypodense area is often visible. Peritumoral vascularity and ball-holding vascularity are frequently observed. In cases with multiple lesions, high signal intensities on DWI and T2WI and nodular enhancement patterns are noted. These distinctive imaging features, particularly peritumoral vascular signs, facilitate accurate diagnosis and differentiation of splenic SANT.

Acknowledgments

We would like to acknowledge the hard and dedicated work of all the staff who implemented the intervention and evaluation components of the study.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2888/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2888/dss

Funding: The study was supported by Henan Province Medical Science and Technology Research Project (No. LHGJ20200487), and the Henan Provincial Key Research and Development Special Project (No. 251111314400).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2888/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study was conducted with approval from the Ethics Committee of The First Affiliated Hospital of Xinxiang Medical University (No. EC-024-525). The First Affiliated Hospital, Zhejiang University School of Medicine served as a collaborating institution that provided anonymized imaging data under inter-institutional data sharing agreements. Written informed consent was obtained from all participants.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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