Sclerosing angiomatoid nodular transformation of the spleen: CT, MR, PET, and ⁹⁹(m)Tc-sulfur colloid SPECT CT findings with gross and histopathological correlation

Clinicopathological analysis of sclerosing haemangiomatoid nodular transformation of the spleen: analysis of three cases and a literature review

OBJECTIVE

To examine the clinicopathological features, immunohistochemical profiles, and differential diagnosis of sclerosing angiomatiod nodular transformation (SANT).

METHODS

Three cases of SANT of the spleen, diagnosed between 2014 and 2023 at the Affiliated Hospital of Zunyi Medical University, were analysed. Pathological features were assessed using haematoxylin and eosin staining, followed by immunohistochemistry with the EnVision system. Additionally, a review of relevant literature was conducted.

RESULTS

The study included one male and two female patients aged 40-55 years, with a median age of 47.5 years. All lesions were solitary, with tumour diameters ranging from 4 to 7.4 cm (mean 5.7 cm). Gross examination demonstrated that the masses were well-demarcated from the surrounding splenic tissue, with no evident capsule. The cut surfaces of the masses exhibited irregular, porcelain-white nodules that were tough in consistency, with some areas intermingling with splenic tissue. Microscopic examination revealed round or circular nodules comprising multiple slit-like or sinusoidal capillaries, separated by concentric collagen fibres. The nodules exhibited chronic inflammatory cell infiltration, calcification, haemosiderin deposition, and fibrous connective tissue with hyaline or mucoid changes. Immunohistochemical analysis demonstrated differential expression of markers, including cluster of differentiation (CD) 34, CD31, and CD8, within the sinusoidal nodule areas. Periodic acid-Schiff staining was positive for perinodular collagen deposits, while reticulin staining highlighted nodule profiles and intranodular vessels. None of the patients experienced postoperative recurrence or metastasis, and one patient was on aspirin for thrombocytosis.

CONCLUSION

SANT of the spleen is generally considered a rare, benign lesion with angioma-like characteristics. It exhibits exhibiting distinctive histomorphological features within the red pulp. Understanding the differential diagnosis is crucial to prevent missed or incorrect diagnoses.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: Radiological Findings and Radiological-pathological Correlation

Introduction

The objective of this study was to describe the CT and MRI features of sclerosing angiomatoid nodular transformation (SANT) of the spleen with pathologic correlation.

Materials and Methods

Ten patients with surgically resected and pathologically confirmed SANTs were included. Clinical history was reviewed, and gross pathologic, histologic, and immunohistochemical findings were recorded. CT and MRI examinations were evaluated by two radiologists.

Results

Patients included seven men and three women, with a mean age of 42.9±16.7 years. Pathologic features of SANTs involved multiple angiomatous nodules in a radiating pattern with a central stellate fibrous scar and evidence of hemosiderin deposition. 9 cases showed a lobulated demarcated margin, 8 cases a slight hypoattenuating, 1 isoattenuating, and 1 case with two lesions demonstrated a slight hyperattenuating margin, respectively. Multiple scattered punctate calcifications were involved in 2 cases. 5 cases manifested hypointensity on in-phase imaging, 1 iso-intensity, and 4 iso-hypointensity on out-of-phase imaging. Progressive and centripetal enhancement were exhibited in 10 cases, spoke-wheel pattern in 3 cases, and nodular enhancement in 4 cases, respectively. The central fibrous scar was identified in 8 cases during delayed enhancement.

Conclusion

Characteristics of SANTs on CT/MRI reflected the underlying pathology. Hypointensity on DWI and T2WI, and change of signal on T1 chemicalshift imaging were found to be due to hemosiderin deposition and fibrous tissue. Typical feature was a solitary, round, lobulated mass with a fibrous scar. Progressive and centripetal enhancement, spoke-wheel pattern, nodular enhancement, and delayed enhancement of central fibrous scar were observed.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: A Report of Rare Case and Literature Review

Sclerosing angiomatoid nodular transformation (SANT) is a benign vascular lesion of the spleen with uncertain etiology. It predominantly affects women between the ages of 30 and 60 years. Clinically, it is asymptomatic or can cause abdominal pain, but usually discovered incidentally on imaging, which can identify a mass but may not provide a definitive diagnosis. In uncertain vascular lesions, there is always a risk of spontaneous rupture of large vessels and the potential for spreading malignancy. Hence, the final diagnosis is rendered on microscopy after splenectomy. A middle-aged female came to the clinic complaining of abdominal pain. Radiology showed a solid splenic mass and the patient underwent splenectomy. Gross examination showed a 3 cm white firm mass with focal hemorrhage. Microscopy revealed multiple nodules of variable sizes surrounded by fibrosclerotic stroma. The nodules showed round to slit-like vascular spaces with numerous red blood cells. The internodular stroma consisted of dense fibrous tissue with scattered plump myofibroblasts and lymphoplasmacytic inflammatory cells. These distinctive features lead to the diagnosis of SANT. SANT possesses characteristic histologic features with distinctive immunohistochemistry (IHC). IHC reveals three different types of vessels within the nodules as follows: (1) small veins (CD34-, CD31+, CD8-), (2) sinusoids (CD34-, CD31+, CD8+), and (3) capillaries (CD34+, CD31+, CD8-). All three types of vessels are negative for CD21/CD35 and CD68. Hemangioma and littoral cell angioma are two frequent vascular tumors in the spleen that should be considered differential diagnoses. Both lesions lack the microscopic features of SANT and have only a single type of vessel. The vessels in hemangioma are (CD31+, CD34+, CD8-), while in littoral cell angioma they are (CD31+, CD34-, CD8-, CD21+, CD68+). There are no specific clinical or radiologic findings for SANT. It is important to recognize these characteristic features and to differentiate them from other benign and malignant lesions, such as angiosarcoma. A thorough histopathologic examination and IHC are helpful in making the correct diagnosis.

Sclerosing angiomatoid nodular transformation of the spleen: multimodality imaging features and literature review

OBJECTIVE

The purpose of this study was to evaluate the CT and MRI findings, clinicopathologic features, and differential diagnosis of Sclerosing angiomatoid nodular transformation (SANT).

METHODS AND MATERIALS

Seven men and seven women with pathological diagnoses of SANT were included in this retrospect study. Patients underwent at least one radiological examination before surgery. The number, shape, margin, size, attenuation, signal intensity, homogeneity, and enhancing pattern of the lesion were evaluated by two abdominal radiologists independently. Immunohistochemistry reports were available for 11 patients. The immunoreactivity to the vascular markers CD8, CD31, and CD34 was assessed.

RESULTS

The 14 SANT patients (7 men, 7 women; mean age, 43.5 years; age range, 24-56 years) presented with a single lesion and showed no specific clinical symptoms. Among 14 patients, 12 patients underwent MR scan, 5 patients underwent CT scan and 3 patients underwent PET-CT. On CT, all 5 lesions showed hypodensity on non-contrast images and spoke-wheel enhancing pattern after contrast administration, and calcification was observed. On T2WI, 10 cases(83.3%)showed hypointensity and 2 cases (16.7%) showed hyperintensity with central hypointensity. On T1WI, 10 cases (83.3%) were isointense and 2 cases (16.7%) were slightly hypointense. 10 cases (83.3%) showed hypointensity on DWI and 2 cases (16.7%) showed slightly hyperintensity on DWI. After contrast administration, all 12 lesions showed progressive enhancement. 18 F-fluorodeoxyglucose (FDG) uptake in the tumor was seen in all three cases that underwent PET-CT. The maximum standardized uptake value (SUVmax) was 4.5, 5.1, and 3.8 respectively.

RESULTS

Apart from the progressive spoke-wheel enhancing pattern, DWI and ADC findings will add value to the diagnosis of SANT.

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.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: A Diagnostic Conundrum

A splenic lesion often represents a diagnostic challenge due to relative scarcity and the broad differential diagnosis. Sclerosing Angiomatoid Nodular Transformation (SANT) of the spleen is usually encountered only incidentally. Although benign, patients with SANT often receive splenectomy, due to its rarity, diagnostic uncertainty and sometimes intimidating imaging morphology and size. Imaging features on computed tomography, magnetic resonance and positron emission tomography have a high diagnostic value for SANT and help differentiate this entity from other splenic lesions. When the imaging parameters are matched with core needle biopsy tissue analysis, further watchful waiting can be recommended in order to avoid splenectomy.

Recent Advances in Gene Therapy for Cancer Theranostics

There is great interest in developing gene therapies for many disease indications, including cancer. However, successful delivery of nucleic acids to tumor cells is a major challenge, and in vivo efficacy is difficult to predict. Cancer theranostics is an approach combining anti-tumor therapy with imaging or diagnostic capabilities, with the goal of monitoring successful delivery and efficacy of a therapeutic agent in a tumor. Successful theranostics must maintain a high degree of anticancer targeting and efficacy while incorporating high-contrast imaging agents that are nontoxic and compatible with clinical imaging modalities. This review highlights recent advancements in theranostic strategies, including imaging technologies and genetic engineering approaches. Graphical Abstract.

Rapidly growing sclerosing angiomatoid nodular transformation of the spleen

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare benign vascular lesion with unknown pathogenesis and no definitive pathognomonic radiological features. The majority of patients with SANT are asymptomatic, and the lesion is an incidental finding on cross-sectional imaging performed for unrelated reasons or during intra-abdominal surgery. However, in the symptomatic minority, abdominal pain is the most commonly reported symptom. SANT generally remains stable or has very slow growth, making it amenable to surveillance using serial cross-sectional imaging. Herein, we report the unusual case of SANT in a 30-year-old female with rapid growth from 6.0 × 5.6 × 4.4 cm to 8.0 × 6.6 × 7.2 cm over 21 months. Given the rapid growth, it was imperative to rule out malignancy. Thus, the patient underwent a laparoscopic total splenectomy. For SANT, splenectomy serves the dual purpose of diagnosis and definitive therapy.

Imaging findings of benign and malignant pediatric splenic lesions

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

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

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

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

BACKGROUND

Sclerosing angiomatoid nodular transformation (SANT) is a rare disease of the spleen. It has unique pathological features and mimics splenic tumor on radiological imaging.

CASE SUMMARY

A 47-year-old woman was incidentally found to have a splenic mass on abdominal ultrasound. She had a 10-cm postoperative scar in the lower abdomen due to previous cesarean sections. The patient had a past history of anemia of unknown etiology for 20 years. The patient underwent laparoscopic splenectomy. The postoperative course was uneventful, with a hospital stay of 7 d. The histopathological examination of the spleen revealed SANT. At the 6-mo follow-up, the patient remained disease-free.

CONCLUSION

SANT is a rare benign disease mimicking a malignant tumor. A definitive diagnosis can be made only on histopathology.

Sclerosing angiomatoid nodular transformation presenting with thrombocytopenia after laparoscopic splenectomy - Case report and systematic review of 230 patients

Background

Sclerosing angiomatoid vascular transformation (SANT) is a rare vascular disease of the spleen, which is difficult to diagnose due to its pre-intervention appearance of malignancy. Case Report: An 85-year-old male was transferred to our clinic for thrombocytopenia and splenic mass. A contrast enhanced abdominal CT and MRI showed nodular lesions, the largest 50mm in diameter, and several areas of heterogeneous contrast field involvement in the spleen parenchyma. Laparoscopic splenectomy was performed with normal range of platelet level. The patient's postoperative course was uneventful and he was discharged on the 6th postoperative day. Histopathology revealed SANT. The patient is now in the 18 th month of remission with platelet levels within normal range and with no recurrence.

Results

Between 2004 and April 2020, a total of 230 SANT patients who underwent laparoscopic or open splenectomy or biopsy were reported in the literature. Most patients were female (52.1%), and the median age was 46 years (9 weeks-85 years). Most patients were asymptomatic (56%). Open splenectomy was performed on 166 patients (72.1%),laparoscopic splenectomy on 35 patients (15.2%) and laparoscopic partial splenectomy on 15 patients (6.5%). The median operation time and spleen weight were 143 minutes (88-213) and 260gr (68-2,720), respectively. Median follow-up time was 12 months (0-166). No recurrence was seen in patients undergoing total splenectomy.

Conclusion

SANT is an unusual disease of the spleen. In the light of this systematic review, a minimally invasive method for total or partial splenectomy,specifically laparoscopy, can be preferred as the treatment of choice.

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SANT is a rare, benign vascular disease of the spleen.

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The correct diagnosis of SANT pre-intervention or preoperatively is a significant for treatment.

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Laparoscopic splenectomy is curative treatment for SANT.

Laparoscopic Splenectomy in a Patient with Sclerosing Angiomatoid Nodular Transformation

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a specific, tumor-forming, non-neoplastic, vascular lesion with few reported cases worldwide. Herein, we describe the case of a patient who underwent laparoscopic splenectomy for SANT. A 47-year-old woman underwent upper gastrointestinal endoscopy for suspected gastric submucosal tumor. Contrast-enhanced abdominal computed tomography revealed the presence of a gradually enhancing lesion in the splenic hilum. Although we suspected splenic fibrotic hamartoma, malignancy could not be ruled out. Therefore, the patient underwent laparoscopic splenectomy, resulting in the histopathological diagnosis of SANT. Although SANT is a benign tumor, it may be difficult to obtain definitive diagnosis using preoperative imaging alone. Because the long-term natural history of SANT is unknown, we believe that splenectomy could be an appropriate technique for the diagnosis and treatment of SANT.

Imaging Features of Sclerosing Angiomatoid Nodular Transformation in Spleen

The purpose of this study was to evaluate the features of sclerosing angiomatoid nodular transformation (SANT) in spleen on the imaging of computed tomography (CT) and magnetic resonance (MR).

Sclerosing angiomatoid nodular transformation presenting with abdominal hemorrhage: First report in infancy

A limited number of sclerosing Angiomatoid Nodular Transformation (SANT) have been reported in pediatric age. We describe the first case of SANT occurring in a nine-week-old female infant that was admitted to our unit for severe abdominal distension and rectal bleeding. Enlarged spleen was detected on physical examination. Laboratory investigations revealed severe anemia and coagulation abnormalities. Abdominal ultrasound and computed tomography revealed ascites and splenomegaly with a large mass at the lower medial splenic pole. A diagnosis of intraabdominal hemorrhage was presumed and an exploratory laparotomy was performed. A complete transformation of the giant splenomegaly to bossellated masses and multiple bleeding capsular ruptures without subcapsular hematoma were found and an urgent splenectomy was performed. At histology, a SANT was diagnosed (CD34, CD31, CD8 positivity). The postoperative follow up was uneventful. SANT may also occur in infancy with a potentially lifethreatening presentation. Splenectomy may represent the only treatment in severe cases.

Sclerosing angiomatoid nodular transformation of the spleen: A case report of thrombocytopenia and a hypervascular splenic mass

Introduction

Sclerosing Angiomatoid Nodular Transformation of the spleen is a benign vascular lesion with no known etiology.

Presentation of Case

We report a new case in a symptomatic twenty-one-year old female with thrombocytopenia and a hypervascular splenic mass discovered on ultrasound. Two MRIs were performed prior to hand-assisted laparoscopic splenectomy. The specimen was sent for histopathologic analysis with confirmation of final diagnosis from an outside facility.

Discussion

Sclerosing Angiomatoid Nodular Transformation of the spleen is most often discovered incidentally as a solitary splenic mass. The presence of a spoke-wheel pattern should alert the radiologist to this as a possibility.

Conclusion

Ultrasound and MR imaging findings can be used to accurately diagnose cases of splenic Sclerosing Angiomatoid Nodular Transformation. Susceptibility artifact within the lesion may be directly related to the amount of iron deposition.

Sclerosing Angiomatoid Nodular Transformation: Laparoscopic Splenectomy as Therapeutic and Diagnostic Approach at the Same Time

Introduction

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare benign vascular lesion with unknown etiopathogenesis and with definite features of imaging, histopathology, and immunohistochemistry. It was first described by Martel et al. in 2004, and to date, only 151 cases have been reported.

Case Description

We report a case of SANT of the spleen detected in a 66-year-old Caucasian, without comorbidities, presented to our department with epigastric pain. We, also, presented a review of the literature.

Conclusions

SANT is a benign incidentally vascular condition in the majority of cases. The wide age and gender distribution in our review is in accordance with that in previous studies in English literature. In our opinion, splenectomy is the choice treatment because it is at the same time diagnostic and therapeutic in a definitive way.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: An uncommon Cause of Abdominal Pain

Sclerosing angiomatoid nodular transformation (SANT) is a rare and benign lesion arising from the red pulp of the spleen, with an unknown etiopathogenesis. These tumors are usually asymptomatic or cause nonspecific abdominal pain. Most SANTs are found incidentally on radiographic examination, or during surgery for an unrelated condition. Therefore, high clinical suspicion is of great importance for the diagnosis. Splenectomy provides complete cure, and no recurrence and/or malignant transformation was reported to date. In this study, a rare case of SANT was reported in a young adult male, and was discussed with the relevant literature.

How to cite this article: Atas H, Bulus H, Akkurt G. Sclerosing Angiomatoid Nodular Transformation of the Spleen: An uncommon Cause of Abdominal Pain. Euroasian J Hepato-Gastroenterol 2017;7(1):89-91.

Laparoscopic splenectomy for sclerosing angiomatoid nodular transformation of the spleen

Sclerosing angiomatoid nodular transformation (SANT) is a rare, benign, proliferative vascular lesion that arises from the splenic red pulp. Most patients with SANT have no clinical symptoms and are discovered incidentally on imaging. There are no definitive radiological signs and a distinction from other splenic diseases, and malignant processes remain difficult. Confirmation of the diagnosis of SANT requires a histological and immunohistochemical evaluation of the resected spleen. Here, we report an unusual case of SANT of the spleen successfully treated with an elective laparoscopic splenectomy (LS). LS is a safe and effective method for diagnosis of SANT.

Multimodality imaging of splenic sclerosing angiomatoid nodular transformation

Sclerosing angiomatoid nodular transformation (SANT) is an exceedingly rare, benign and proliferative vascular lesion that arises from the splenic red pulp. It is often an incidental finding on imaging. The diagnosis of SANT is confirmed via histopathological examination of the resected spleen. Herein, we present a case of SANT and describe its typical imaging characteristics. An asymptomatic 39-year-old man was found to have a 3.1 cm × 2.7 cm × 2.3 cm hypoechoic splenic lesion during abdominal ultrasonography, which was performed to investigate his elevated gamma-glutamyl transpeptidase and alanine transaminase levels. Contrast-enhanced computed tomography suggested a vascular splenic lesion, while magnetic resonance imaging demonstrated features consistent with SANT. In view of the increasing size of the lesion on follow-up imaging, the patient elected for splenectomy. Histopathological examination confirmed SANT, and the lesion was completely resected by laparoscopic splenectomy.

Sclerosing angiomatoid nodular transformation (SANT) of the spleen: a case report with FDG-PET findings and literature review

We report the 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) findings of sclerosing angiomatoid nodular transformation (SANT) of the spleen. The patient was a 37-year-old woman with a splenic mass incidentally found on abdominal ultrasound. FDG-PET/CT showed weak FDG accumulation (maximum standardized uptake value = 3.65). An unenhanced CT scan showed a low density and well-circumscribed splenic tumor that demonstrated weak enhancement from the arterial to delayed phase. Although hemangioma or hamartoma of the spleen was preoperatively diagnosed, histopathological examination revealed SANT. Therefore, when a splenic tumor with weak contrast medium enhancement and low FDG accumulation is observed, SANT should be considered as a differential diagnosis. Although CT and magnetic resonance imaging features of SANT have been reported, there are few reports on FDG-PET/CT findings. We report the radiological features of SANT, including FDG-PET/CT, and review the literature on SANT.

Sclerosing Angiomatoid Nodular Transformation of Spleen in a 3-year-old Child

BACKGROUND

Reports of sclerosing angiomatoid nodular transformation in the pediatric population are rare.

CASE CHARACTERISTICS

The 3-year-old child was injured in a car accident and then diagnosed with sclerosing angiomatoid nodular transformation. The patient underwent exploratory surgery with partial splenectomy including total excision of the tumor mass.

OUTCOME

Neither recurrence nor metastasis occurred over 20 months of follow-up.

MESSAGE

Sclerosing angiomatoid nodular transformation can occur in early childhood.

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.

Sclerosing angiomatoid nodular transformation of the spleen during pregnancy: Diagnostic challenges and clinical management

We report the first case of sclerosing angiomatoid nodular transformation (SANT) of the spleen diagnosed during pregnancy, discussing differential diagnosis, immunohistochemical profile and treatment. A G2P1 37-year-old woman presented during the 19th week of gestation because of pruritus at lower limbs. To exclude cholestasis, an abdominal ultrasound and whole body magnetic resonance were performed and a single solid lesion with intrinsic vascularization was identified. Therefore, at 22 weeks gestation, after normal fetal assessment, the patient was referred for a splenectomy. No further treatment was suggested and the patient gave birth at 42 weeks gestation with a spontaneous delivery. Distinguishing SANT from other vascular neoplasms of the spleen during pregnancy is a difficult task. Surgical excision should be performed to exclude malignancy and to resolve symptoms, if present.

FDG PET/CT Findings in Multiple Splenic Amebomas (Amebic Granulomas)

Splenic ameboma (amebic granuloma) is rare. A 38-year-old man with a severe pneumonia due to inhalation of swimming pool water 18 months ago complained of night sweat, tiredness, and anorexia for 1 month. Abdominal ultrasound showed multiple nodules in the spleen. These nodules showed slight enhancement on enhanced CT and intense FDG uptake on PET/CT. Splenectomy was performed. Multiple splenic amebomas were confirmed by pathology. Free-living amoebae were also detected in samples of pleural effusion and blood. Splenic ameboma, although rare, should be included in the differential diagnosis with isolated focally increased FDG activity in the spleen.

Enhanced CT and FDG PET/CT findings of splenic hamartoma

Splenic hamartomas are very rare benign vascular tumors. A 67-year-old man was referred after an incidental detection of a splenic lesion. Abdominal-enhanced CT showed a splenic lesion with progressive enhancement. This lesion showed intense FDG uptake with an SUVmax of 9.2. The patient underwent splenectomy. Splenic hamartoma was confirmed by pathologic evaluation. In this tumor, the disorganized splenic sinus contained a large amount of lymphocytes and plasma cells, which may contribute to the intense FDG uptake. This case indicates that splenic hamartoma should be included in the differential diagnosis of focal FDG accumulation along with tumor and nontumor conditions.

Two cases of sclerosing angiomatoid nodular transformation of the spleen with gradual growth: usefulness of diffusion-weighted imaging

Sclerosing angiomatoid nodular transformation (SANT) is a recently recognized and rare, nonneoplastic lesion of the spleen. Some papers have reported an increased SANT diameter during the follow-up period. We present two cases of SANT whose size increased during the follow-up period. Diffusion-weighted magnetic resonance imaging (DWI) findings correlated well with the pathological findings of SANT, the multinodular high-intensity area as the angiomatoid nodules and the peripheral low-intensity area as fibrous tissues. Therefore, DWI may be a useful imaging tool.

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

OBJECTIVE

Splenic lesions are commonly encountered and are often incidental in nature. Benign splenic vascular neoplasms include hemangioma, hamartoma, lymphangioma, extra-medullary hematopoiesis (EMH), and sclerosing angiomatoid nodular transformation (SANT). Uncommonly encountered entities of the spleen include focal EMH, focal myeloma, angiomyolipoma, and SANT. Primary splenic angiosarcoma is the most common malignant nonhematolymphoid malignancy of the spleen. Lymphoma, myeloma, and metastases are the other malignant entities involving the spleen. The clinical presentation, key imaging findings, and associations of benign, neoplastic, and malignant diseases that can involve the spleen will be discussed.

CONCLUSION

Radiologists can use multimodality imaging to diagnose entities involving the spleen by recognizing key imaging features and considering patient characteristics. However, biopsy may be warranted for definitive diagnosis when imaging findings are nonspecific.

A case of sclerosing angiomatoid nodular transformation of the spleen: correlations between contrast-enhanced ultrasonography and histopathologic findings

Sclerosing angiomatoid nodular transformation (SANT) is a recently recognized benign vascular lesion of the spleen. Detection of SANT as an incidentaloma has increased due to improvements in imaging techniques. However, a definitive diagnosis of SANT on CT or MRI remains difficult. We report the use of contrast-enhanced ultrasonography with Sonazoid in a case of SANT in a 50-year-old woman, with gross and microscopic pathologic correlations.

Sclerosing angiomatoid nodular transformation of the spleen (SANT): multimodality imaging appearance of five cases with radiology-pathology correlation

OBJECTIVE

Sclerosing angiomatoid nodular transformation (SANT) is an extremely rare splenic lesion first reported in 2004, representing an unusual reaction of splenic red pulp to stromal inflammation or vascular injury. There are very few descriptions of the imaging appearance of SANT in the literature. We present five pathologically proven cases of SANT, with a description of the imaging appearance using multiple different modalities, as well as correlation with the histopathologic features of the lesion.

CONCLUSION

While there are several imaging features of SANT which have been described in the literature, it is not routinely possible to make a prospective diagnosis based on the imaging features alone. Moreover, it may not be possible to exclude malignancy based on the imaging features, and splenectomy may be required in certain cases.

Sclerosing angiomatoid nodular transformation of the spleen: CT and MRI features with pathologic correlation

OBJECTIVE

The objective of this study was to describe the CT and MRI features of sclerosing angiomatoid nodular transformation of the spleen with pathologic correlation.

MATERIALS AND METHODS

Nine patients with surgically resected and pathologically confirmed sclerosing angiomatoid nodular transformation were included in the study. Clinical history was reviewed to determine patient demographics and symptoms at presentation. Gross pathologic, histologic, and immunohistochemical findings were recorded. CT (n = 9) and MRI (n = 4) examinations were evaluated for lesion shape and margins, intrinsic characteristics, and enhancement pattern.

RESULTS

Patients included were six women and three men, with a mean age of 41.2 years. Pathologic features of sclerosing angiomatoid nodular transformation included multiple angiomatous nodules in a radiating pattern with a central stellate fibrous scar and evidence of hemosiderin deposition. On imaging, the lesions were solitary and round, 78% having a lobulated margin. They were heterogeneously hypoenhancing during the arterial and portal venous phases of contrast-enhanced CT or MRI, with peripheral enhancing radiating lines in 88% of lesions. They showed progressive enhancement and were isoenhancing or hyperenhancing in the delayed phase. A hypoenhancing central scar was shown on imaging in 22% of lesions. All lesions were hypointense on T2-weighted images.

CONCLUSION

Sclerosing angiomatoid nodular transformation shows characteristic CT and MRI findings reflecting the underlying pathology. Typical features are a solitary, round, lobulated mass with early peripheral enhancing radiating lines and progressive enhancement of the angiomatous nodules; delayed enhancement of the fibrous tissue; and hypo-intense T2 signal intensity from hemosiderin deposition.

Sclerosing angiomatoid nodular transformation of the spleen related to IgG4-associated disease: report of a case

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare benign vascular mass, with fewer than 100 cases documented. It is generally recognized as a vascular lesion that develops in the red pulp of the spleen; however, its pathogenesis is not clearly defined. We report a case of SANT of the spleen, which presents evidence to support the hypothesis that this disease entity is associated with IgG4-associated disease. Microscopically, the tumor was composed of multiple vascular structures separated by fibrous connective tissue and immunohistochemical examination revealed positive staining for CD31, CD34, factor VIII, and IgG4. Further research based on large number of cases is warranted to clarify the pathogenesis of this tumor.

Sclerosing angiomatoid nodular transformation of the spleen: clinical and radiologic characteristics

BACKGROUND

Sclerosing angiomatoid nodular transformation (SANT) is a rare benign primary vascular lesion of the spleen. Although there have been many reports about the pathology of SANTs of the spleen, there have been no comprehensive descriptions of the imaging findings of SANTs of the spleen.

PURPOSE

To determine the clinical characteristics and imaging findings of SANTs of the spleen.

MATERIAL AND METHODS

We retrospectively evaluated seven patients with pathologically confirmed SANT, who underwent CT (n = 7), MRI (n = 4), ultrasonography (n = 4), and PET/CT (n = 3). Follow-up CT examinations were obtained in five patients. Clinical characteristics such as symptoms and concurrent disease were assessed. CT and MRI findings were evaluated by two radiologists, including the number, border, signal intensity, enhancement pattern, hemorrhage, and cystic change or necrosis. The longest diameter of each tumor was measured on CT. Echogenicity on ultrasonography and standardized uptake value on PET/CT were also evaluated.

RESULTS

No specific symptom was associated with SANT. Two patients had a history of malignancy, one with cervical cancer and the other with early gastric cancer. Tumor growth was observed in four of five patients. On CT, all seven SANTs appeared as single, well-demarcated masses. CT showed a heterogeneous enhancement in seven patients. MRI showed centripetal progressive enhancement and absence of cystic change or necrosis in four patients, with three of these patients showing evidence of old hemorrhage. Ultrasonography showed heterogeneous hypoechoic mass in four patients. PET/CT showed increased standardized uptake value, ranging from 2.0 to 2.8, in three patients.

CONCLUSION

SANT of the spleen is a single, well-demarcated solid mass without cystic change or necrosis. Increased FDG activity and tumor growth on follow-up imaging are common.

Sclerosing Angiomatoid Nodular Transformation (SANT) of the spleen: Case report and review of the literature

INTRODUCTION

Sclerosing Angiomatoid Nodular Transformation of the spleen (SANT) is a rare benign vascular lesion of the spleen with extensive sclerosis and unknown etiology.

PRESENTATION OF CASE

We report a new case of SANT of the spleen found in a 53-year-old female following detection of a splenic mass on a routine computed tomography (CT). The patient underwent an uncomplicated laparoscopic splenectomy and the specimen was sent for histopathologic examination.

DISCUSSION

A review of the 97 reported cases of SANT found in the literature was undertaken. There were 43 males and 54 females with a median age of 46 years (range: 11-82 years). SANT is classically considered to be a female predominant disease, however 44.3% of reported case were male and the gender predilection may soon be neutralized as more cases are reported. 65 of the 97 (67%) patients were in 30-60 year age group. The majority of lesions (n=50) were incidentally found on imaging, and for those patients presenting with symptoms, abdominal pain (n=18) was the predominant symptom.

CONCLUSION

The diagnosis of SANT should be considered in any patient presenting with a splenic lesion that contains an angiomatoid or inflammatory component. As the differential diagnosis for SANT includes malignant pathologies, and currently no reliable diagnostic radiological feature has been identified to differentiate between these conditions, SANT will continue to be diagnosed on the basis of surgical histopathology.

[Laparoscopic splenectomy for sclerosing angiomatoid nodular transformation]

Sclerosing angiomatoid nodular transformation (SANT) is a benign lesion of the spleen which can be cured by splenectomy. In the literature about 45 cases have been reviewed. Although it is defined by the morphological details, data regarding surgical therapy are scarce. To the best of our knowledge, a laparoscopic approach has not been published before. We investigated in one case of SANT the feasibility of a laparoscopic approach. Histological investigations confirmed the diagnosis of a SANT which was resected in toto. This report shows that the laparoscopic splenectomy is a feasible, safe and effective method for treatment of SANT.