Sclerosing angiomatoid nodular transformation (SANT) of the spleen: addition of a case with focal CD68 staining and distinctive CT features

A rare case of sclerosing angiomatoid nodular transformation of spleen: A case report

INTRODUCTION AND IMPORTANCE

Sclerosing angiomatoid nodular transformation of the spleen is a rare benign vascular lesion arising from red pulp of spleen with unknown etiopathogenesis. It is a non-neoplastic condition that affects the spleen only; not described in other sites except one case reported in adrenal gland. Epidemiologically it has slight female predilection. It is a very rare ailment where the present finding is very crucial in the management of similar cases so far.

CASE PRESENTATION

A 31 years old female patient presented with left flank pain and constipation of 01 year duration. An abdominopelvic CT scan showed a hypodense mass in the left upper quadrant of abdomen just anterior to inferior pole of spleen with the conclusion of mesenteric mass likely gastrointestinal stromal tumor. Finally, it was decided and exploratory laparotomy was done and the surgeon identified the mass in the inferior pole of spleen and total splenectomy was done, and the specimen is sent for pathologic evaluation. The final histopathologic diagnosis became sclerosing angiomatoid nodular transformation of spleen with the classic microscopic findings of multiple confluent angiomatoid nodules surrounded by variable concentric fibrosclerotic stroma.

CLINICAL DISCUSSION

Sclerosing angiomatoid nodular transformation of spleen is a benign incidentally identified vascular condition of red pulp in the majority of cases. Preoperative diagnosis is not easy since it is difficult to obtain the tissue from the spleen for pathological study. Recently, splenectomy has become the more standard procedure for the spleen for both diagnosis and treatment with no recurrence reported after splenectomy.

Diagnostic approach to splenic lesions

BACKGROUND

Splenic lesions are rare and mostly incidental findings on cross-sectional imaging. Most lesions are of benign nature and can be correctly identified based on imaging characteristics. Further, invasive evaluation is only necessary in cases of splenic lesions with uncertain or potentially malignant etiology.

METHOD

While in most cases a correct diagnosis can be made from computed tomography (CT), (additional) magnetic resonance imaging (MRI) can aid in the identification of lesions. As these lesions are rare, only a few of the differential diagnoses are regularly diagnosed in the clinical routine.

RESULT AND CONCLUSION

This review presents the differential diagnoses of splenic lesions, including imaging characteristics and a flowchart to determine the right diagnosis. In conjunction with laboratory results and clinical symptoms, histological workup is necessary only in a few cases, especially in incidental findings. In these cases, image-guided biopsies should be preferred over splenectomy, if possible.

KEY POINTS

· Splenic lesions are rare and are usually incidental findings on abdominal imaging. · CT imaging and MRI imaging are the diagnostic tools of choice for the further workup of splenic lesions. · Based on their image morphological characteristics, a large number of splenic lesions can be assigned to one entity and do not need histological analysis.

CITATION FORMAT

· Krähling H, Seidensticker M, Heindel WL et al. Diagnostic approach to splenic lesions. Fortschr Röntgenstr 2024; 196: 573 - 581.

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 (SANT): A Rare Splenic Tumor and Unusual Cause of Anemia

Patient: Male, 57-year-old

Final Diagnosis: Sclerosing angiomatoid nodular transformation (SANT) of spleen

Symptoms: Anemia

Medication:—

Clinical Procedure: Splenectomy

Specialty: Surgery

A Splenic IgG4+ Sclerosing Angiomatoid Nodular Transformation (SANT) Treated by Hemisplenectomy: A Radiologic, Histochemical, and Immunohistochemical Study

INTRODUCTION

Sclerosing angiomatoid nodular transformation (SANT) is a rare benign lesion of unknown origin for which total splenectomy is the standard treatment.

CASE PRESENTATION

A 54-year-old man with a history of recurrent pancreatitis, bicuspid aortic valve, and aortic dissection underwent abdominal ultrasound, Computed tomography and magnetic resonance imaging, which revealed a 6-cm hypoechoic splenic mass diagnosed as cavernous hemangioma. Owing to his relevant past history, he was considered eligible for emisplenectomy and not for total excision, which is associated with long-term risks, especially infections.

RESULTS

Histologic examination revealed several nodules of varying size separated by sclerotic stroma with scattered inflammatory cells rich in IgG4+ in a background of splenic red pulp. Immunohistochemical stains showed a characteristic panel for CD34, CD31, and CD8.

CONCLUSIONS

The diagnosis of SANT should be considered in any patient presenting with a splenic lesion containing an angiomatoid or inflammatory component. The only method able to establish a correct diagnosis is histologic and immunohistochemical evaluation. Complete splenectomy is generally considered the best approach. However, if the patient is at high risk of infection and localization of the lesion allows for selective devascularization of the affected part of the spleen, the lesion could be removed by hemisplenectomy. In some patients SANT is related to high blood levels of IgG4. Thus, corticosteroids might be useful for treating IgG4+ SANT and for preventing other IgG4-related diseases.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: Analysis of Clinical and Pathological Features in Five Cases

Objective: We aimed to summarize the clinical and pathological features of sclerosing angiomatoid nodular transformation (SANT) in spleen among five cases.

Methods: Five cases (male: 3; female: 2; mean age: 47.6 years) with SANT confirmed by pathological analysis between July 2010 and November 2019 in our hospital were included in this study. The clinical, imaging, and pathological data were analyzed retrospectively.

Results: Three patients presented with mild abdominal pain or discomfort, while the other two were symptom free. Two patients received ultrasonography (US), and all patients underwent a computerized tomography (CT) scan in our hospital. The typical “spoke wheel” pattern was seen in two cases, and central calcification was detected in one case on the CT scans. All patients indicated peripheral enhancement around the SANT lesion during the arterial phase. Open or laparoscopic splenectomy was performed for treatment. No patient showed recurrence in the follow-up. The pathological characteristics of our cases were in line with those of previous literatures.

Conclusions: Peripheral enhancement around the SANT lesion during the arterial phase should be taken into consideration for the diagnosis of SANT as an imaging sign on CT scans. Special attention should be paid to the splenic integrality during the laparoscopic approach, due to the probability of malignancy and the fragility of the spleen.

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 (SANT) of spleen mimicking a splenic abscess: Case report and review of the literature

INTRODUCTION

SANT of the spleen is a benign lesion that does not recur after splenectomy with unknown etiology.

PRESENTATION OF THE CASE

We report a case of sclerosing angiomatoid nodular transformation (SANT) of the spleen mimicking a splenic abscess in a patient with imaging studies that failed to differentiate this lesion from other splenic lesions.

DISCUSSION

SANT of the spleen is a rare condition, with only less than 100 cases reported in the literature. Clinically, SANT is only a kind of described pathological diagnostic conception. As in our case, these splenic lesions are often incidental findings on imaging studies performed for other reasons.

CONCLUSION

The patient was treated with splenectomy, which has proved to be both diagnostic and therapeutic. Although histology can lead to the diagnosis of vascular tumor, immunohistochemistry is the only way to confirm the diagnosis.

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 of the spleen mimicking metastasis of melanoma: a case report and review of the literature

BACKGROUND

Sclerosing angiomatoid nodular transformation is a benign disorder of splenic tissue and is often mistaken as a potentially malignant entity in the diagnostic process. To the best of our knowledge, this is the first report of sclerosing angiomatoid nodular transformation mimicking metastasis of melanoma in the literature.

CASE PRESENTATION

A 43-year-old white man presented with a newly found splenic mass 4 years ago to our Department of Gastroenterology. He was diagnosed as having a superficial spreading malignant melanoma localized at his left instep 7 years ago and was successfully treated with radical local resection. Several diagnostic procedures were conducted. Ultrasound showed a hypoechoic lesion in the inferior pole of his spleen with a diameter of 2 cm, blurred boundaries, and inhomogeneous interior pattern. Contrast-enhanced ultrasound was inconclusive and showed only discrete contrast enhancement of the lesion with accentuated nodule-like enrichment of the boundaries in the arterial phase. Computed tomography and magnetic resonance imaging scans showed two splenic lesions which were highly suspicious of metastasis. Magnetic resonance imaging of his head was inconspicuous. Bone scintigraphy showed no abnormal results. Fine-needle aspiration indicated metastasis of the above-mentioned malignant melanoma. We conducted a laparoscopic splenectomy. His intraoperative and postoperative course were uneventful. In contrast to the result of the fine-needle aspiration, the presence of metastasis of melanoma could not be confirmed. Histological analysis revealed nodule-like arrangement of fibroblasts with low cell density and a predominance of dilated capillaries, indicating sclerosing angiomatoid nodular transformation of the spleen.

CONCLUSIONS

There are no preoperative diagnostic imaging procedures which can definitely differentiate sclerosing angiomatoid nodular transformation from malignancies in cases of morphological and immunophenotypic variations of the specimen. Morphological and immunophenotypic variations of the specimen represent a diagnostic challenge and can mimic malignoma. As reported in our case, the specimen obtained by ultrasound-guided fine-needle aspiration led to the diagnosis of metastasis of melanoma. Splenectomy is often conducted due to a splenic mass suspicious of malignoma as described in our case or with unknown valency in different diagnostic imaging procedures.

A case of sclerosing angiomatoid nodular transformation of the spleen with increased accumulation of fluorodeoxyglucose after 5-year follow-up

•

Although sclerosing angiomatoid nodular transformation (SANT) of the spleen is a new entity defined as a benign pathologic lesion, it is very difficult for ruling out the malignancy in preoperative imaging studies.

•

Even when accumulation of fluorodeoxyglucose increased slightly during the follow-up period and suggested the possibility of malignant diseases, it is necessary to make a diagnosis of splenic SANT comprehensively.

Introduction

Sclerosing angiomatoid nodular transformation (SANT) of spleen is a new entity defined as a benign pathologic lesion. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) shows weak accumulation, thereby ruling out the malignancy in preoperative diagnosis is difficult. Herein, we reported a case of shrinking SANT with increased FDG accumulation during a 5-year follow-up period, which was treated by laparoscopic splenectomy.

Presentation of case

A 64-year-old female had been referred to our hospital for the evaluation of a splenic tumor. Initial contrast-enhanced computed tomography (CT) showed a well-defined, and ovoid hypoattenuating lesion, measuring 52 mm in diameter in the spleen. Initial PET/CT revealed accumulation of FDG in the tumor (maximum standardized uptake value [SUVmax]: 2.8). The mass was diagnosed as SANT, and the patient was followed-up every 6–12 months for 5 years. Follow-up PET/CT revealed increased accumulation of FDG (SUVmax: 3.5). As it was suspicious considering the differential diagnosis, including malignant lymphoma and inflammatory pseudotumor, she underwent laparoscopic splenectomy. The pathological results showed three types of vessels including capillaries, ectatic small veins, and sinusoids-like vessels, consistent with the features of SANT.

Discussion

A SANT may have features that resemble those of malignancy, including the growing mass and the increase of FDG accumulation.

Conclusion

Although the preoperative diagnosis of SANT is difficult, it is necessary to make a diagnosis of SANT comprehensively, even when accumulation of FDG increased slightly during the follow-up period and suggested the possibility of malignant diseases.

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.

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 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.

Multifocal sclerosing angiomatoid nodular transformation of the spleen: a case report and review of literature

Sclerosing angiomatoid nodular transformation (SANT) is a relatively new entity in the spleen, which usually presents in the form of single nodule. Only 5 multifocal SANT cases have been reported in English literature. The present case is the first report of a 38-years-old male patient with SANT in the form of multiple nodules, who has been cured via laparoscope. In comparison to solitary SANT, multifocal SANT occurs more likely in males than females and association with malignant neoplasm has not been described yet. Multifocal SANT as well as solitary SANT show some relationships with IgG4-related sclerosing disease.

Sclerosing angiomatoid nodular transformation of the spleen

Sclerosing Angiomatoid Nodular Transformation (SANT) of the spleen is a rare benign lesion of the spleen with unknown etiology. SANT is classically considered to be a female-predominant disease, with most of the patients in the 30- to 60-year age group. Most lesions are found incidentally on imaging. Although SANT has specific imaging findings, the differential diagnosis from other splenic tumors or malignant lesions is very difficult. Histopathologically, these tumors reveal multiple confluent angiomatoid nodules; these nodules are surrounded by concentric collagen fibers exhibiting an inflammatory and myofibroblastic response and are accompanied by numerous erythrocytes and siderophages. The nodules are populated by endothelial cells, phenotypically recapitulating normal splenic vasculature, such as sinusoids, capillaries, and small veins. Nuclear atypia is minimal, mitotic figures are extremely rare, and necrosis is consistently absent. This lesion has a unique immunohistochemical profile characterized by CD34(-)CD31(+)CD8(+) sinusoids, CD34(+)CD31(+)CD8(-) capillaries, and CD34(-)CD31(+)CD8(-) small veins. CD68 is positive in macrophages. Splenectomy is a useful and effective technique for the management of SANT. SANT patients have a good prognosis, with no recurrence after splenectomy. In this review, we discuss the current knowledge of SANT of the spleen and its clinical relevance.

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: 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.

Sclerosing angiomatoid nodular transformation of the spleen treated by laparoscopic partial splenectomy

The authors describe a case of sclerosing angiomatoid nodular transformation (SANT) of the spleen treated at the 2^nd Department of Surgery, Jagiellonian University, Medical College. The patient was a 23-year-old woman. Clinically she presented with 2-year history of recurrent mild fever, diffuse joint pain, abdominal discomfort and iron deficiency anaemia of chronic disease. The laboratory tests revealed a non-characteristic chronic inflammatory response. A splenic solid lesion 9 cm in diameter was found on abdominal computed tomography. The patient underwent uneventful laparoscopic resection of the upper half of the splenic parenchyma. The resected tumour showed characteristic histological and immunophenotypical findings of SANT as previously described in the literature. In long-term follow-up, improvement of preoperative symptoms and abnormalities in the blood tests was documented.

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

Sclerosing angiomatoid nodular transformation (SANT) is a benign, proliferative vascular lesion affecting the spleen. Few reports detailing the cross sectional and PET appearance of this lesion are available, and the lesion’s behavior with ^99mTc-sulfur colloid scintigraphy is previously unreported. Sclerosing nodular transformation of the spleen shows increased tracer accumulation on positron emission tomography, and a central scar-like appearance with an enhancing capsule and radiating septae on CT and MR studies that reflects the gross and histopathological features of the lesion may be visible. An understanding of this pathological finding may allow prospective recognition of the sclerosing nodular transformation of the spleen on cross sectional imaging studies.

Sclerosing angiomatoid nodular transformation of the spleen masquerading as a sarcoma metastasis

We report a case of sclerosing angiomatoid nodular transformation (SANT) of the spleen presenting as an incidental splenic mass in a patient with a history of retroperitoneal spindle cell sarcoma. Imaging studies and preoperative fine needle biopsy failed to differentiate this lesion from other vascular splenic lesions or a metastatic focus of a prior sarcoma. The patient was treated with splenectomy, which has proved both diagnostic and therapeutic in this and other cases of SANT. Although histology can lead to the diagnosis of vascular tumor, immunohistochemistry is the only way to confirm the diagnosis of SANT. The etiology of SANT is unknown. SANT of the spleen is a benign lesion that does not recur after splenectomy.

Sclerosing angiomatoid nodular transformation of the spleen masquerading as a sarcoma metastasis

We report a case of sclerosing angiomatoid nodular transformation (SANT) of the spleen presenting as an incidental splenic mass in a patient with a history of retroperitoneal spindle cell sarcoma. Imaging studies and preoperative fine needle biopsy failed to differentiate this lesion from other vascular splenic lesions or a metastatic focus of a prior sarcoma. The patient was treated with splenectomy, which has proved both diagnostic and therapeutic in this and other cases of SANT. Although histology can lead to the diagnosis of vascular tumor, immunohistochemistry is the only way to confirm the diagnosis of SANT. The etiology of SANT is unknown. SANT of the spleen is a benign lesion that does not recur after splenectomy.

Case report and magnetic resonance images of sclerosing angiomatoid nodular transformation (SANT) of the spleen

A 40-year-old woman presented with a 2 year history of intermittent left upper quadrant pain. The clinical examination and blood tests were normal, but the pain persisted. An ultrasound scan of the abdomen revealed a hypoechoic mass in the spleen which was further investigated by computed tomography and magnetic resonance imaging (MRI). The differential diagnosis included solitary lymphoma, splenic haematoma, sarcoma, solitary metastasis or partially thrombosed splenic artery aneurysm. The patient underwent elective splenectomy and histology showed the appearance of a rare tumour. We present MRI images of this very rare splenic tumour.

Splenic angiomatoid nodular transformation in a child with increased erythrocyte sedimentation rate

An 11-year-old girl was referred to the authors' hospital with a complaint of growth retardation. Physical examination revealed splenomegaly. Laboratory examination revealed increased sedimentation rate. Her imaging studies showed a splenic mass. Splenectomy was performed and histopathological examination revealed sclerosing angiomatoid nodular transformation (SANT) of the spleen. The disease rarely affects children but it could cause growth retardation and increased sedimentation rate, mimicking the chronic inflammatory diseases.

Sclerosing angiomatoid nodular transformation of the spleen presenting as a rapidly growing tumour in a patient with rectal cancer

A patient with rectal cancer developed a rapidly growing splenic mass 2 years after cancer treatment. Since a metastatic process could not be ruled out, splenectomy was performed, and the tumour emerged as a sclerosing angiomatoid nodular transformation (SANT) of the spleen. SANT is a rare, recently recognised, non-neoplastic vascular lesion of the spleen that radiologically may be difficult to distinguish from vascular splenic lesions such as splenic hamartoma, haemangioma or littoral cell angioma. However, morphologically and immunohistochemically it is separated from those tumours by its unique nodular angiomatoid proliferation pattern. SANT is considered to be a benign lesion. This case is reported because of its important clinical impact for the differential diagnosis of splenic masses. Data regarding growth rates of these lesions are scarce and a growth progression as in this case, that finally led to the indication for splenectomy due to lingering suspicion of malignancy, is novel.

Sclerosing Angiomatoid Nodular Transformation (SANT) of the Spleen: A Report of 3 Cases

The authors describe 3 cases of sclerosing angiomatoid nodular transformation (SANT) of the spleen diagnosed at Memorial Sloan-Kettering Cancer Center within a 1-year period (July 2008 to June 2009). All patients were female, older than 50, with lesions ranging in size from 2 to 4 cm. All were alive and well after splenectomy. All the cases showed characteristic histological and immunophenotypical findings as previously described in the literature, including scattered IgG4positive plasma cells in the fibrosclerotic stroma. Of the 3 patients, 2 had a history of carcinoma, and metastasis was of concern, but a PET scan in one of these patients showed minimal to absent FDG activity suggesting that this process was of a benign indolent nature. However, in 1 patient, a PET scan revealed positive FDG activity, heightening clinical concern for malignancy.

Sclerosing angiomatoid nodular transformation (SANT) of the spleen: sonographic finding

Sclerosing angiomatoid nodular transformation (SANT) is a recently recognized benign vascular lesion of the spleen. There is limited information regarding its imaging findings of this condition. Until now, the diagnosis was based on histopathologic examination of splenectomy specimens. We report the sonographic findings in a case of SANT of the spleen confirmed by ultrasound-guided core needle biopsy.

CT and MRI findings of sclerosing angiomatoid nodular transformation of the spleen: spoke wheel pattern

Sclerosing angiomatoid nodular transformation of the spleen is a recently described benign pathologic entity that is characterized by round shaped vascular spaces that are lined by endothelial cells, and the spaces are circumscribed by granulomatoid structures. Microscopically, all the reported cases had multiple angiomatoid nodules in a fibrosclerotic stroma. Each angiomatoid nodule was made up of slit-like, round or irregular shaped vascular spaces that were lined by endothelial cells and interspersed ovoid cells. We present here the CT and dynamic gadolinium-enhanced MR findings of a patient with sclerosing angiomatoid nodular transformation. The spoke-wheel pattern that was observed on MRI in this case may be an important imaging clue for making the correct diagnosis of this benign lesion.

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

We report a case of sclerosing angiomatoid nodular transformation of the spleen incidently discovered in a 41-year-old man. The macroscopic examination showed the presence of a reddish brown, well delineated but not encapsulated, multinodular lesion being histologically characterized by nodules made up of complex vascular structures lined by monomorphous but non atypical endothelial cells, surrounded by fibrin and a collagen stroma rich in spumous macrophages and hemosiderophages. The immunohistochemical markers carried out showed the presence of capillaries, veins and sinusoids normally found within the splenic parenchyma, but adopting an unusual configuration. This distinct entity, recently described and completely benign, must be included in the differential diagnosis of the vascular lesions of the spleen, which includes, among others, the hemangioma, the littoral cell angioma, the hemangioendothelioma and the inflammatory myofibroblastic tumor.

Sclerosing Angiomatoid Nodular Transformation of the Spleen

Sclerosing angiomatoid nodular transformation (SANT) is a recently recognized nonneoplastic vascular lesion of the spleen with fewer than 30 cases described. Microscopically, SANT consists of multiple well-circumscribed vascular/ angiomatoid nodules showing plump endothelial cell and extravasated erythrocytes. The nodules are surrounded by a variable lymphoplasmacytic infiltrate, spindle cells, and collagenous stroma. The vascular nodules display a complex mixture of endothelial phenotypes resembling splenic sinusoids (CD34−/CD31+/CD8+), capillaries (CD34+/ CD31+/CD8−), and small veins (CD34−/CD31+/CD8−). Focal expression of CD68 can also be seen. The differential diagnosis of SANT includes splenic hamartoma, inflammatory myofibroblastic tumor, littoral cell angioma, and hemangioendothelioma. It has been postulated that SANT represents a peculiar hamartomatous transformation of splenic red pulp in response to an exaggerated nonneoplastic stromal proliferation. SANT has a benign clinical course with splenectomy being curative.

Coexisting sclerosing angiomatoid nodular transformation of the spleen with multiple calcifying fibrous pseudotumors in a patient

Primary tumor or tumor-like lesions of the spleen are rare. Among them, vascular lesions are the most common. Vascular tumor of the spleen is different from the usual hemangioma of soft tissue because the vascular structure of the spleen is unique. Sclerosing angiomatoid nodular transformation (SANT) is a recently described vascular lesion of the spleen. Grossly, it is a multinodular, well-circumscribed tumor containing a hypervascular core. Microscopically, it comprises three types of vessels, and each type recapitulates the immunohistochemical characteristics of the normal vascular elements of the splenic red pulp, i.e. capillaries, sinusoids, and small veins, respectively. Because of the rarity of this entity, its actual pathogenesis is still unknown. In this study, we report a case of SANT occurring in a 43-year-old woman, in whom there were also multiple calcifying fibrous pseudotumors (CFPTs) in the abdominal cavity. Both SANT and CFPT are thought to be variants of inflammatory pseudotumor. Coexistence of these two rare entities in a patient has never been reported, and this fact suggests that there might be a common mechanism contributing to the formation of these two types of lesions.

CD30 and Epstein-Barr virus RNA expression in sclerosing angiomatoid nodular transformation of spleen

Sclerosing angiomatoid nodular transformation (SANT) is a splenic lesion composed of angiomatoid/vascular nodules surrounded by hyalinized/sclerotic stroma, fibroblasts, myofibroblasts, and inflammatory cells. The endothelium within the nodules has a phenotype resembling splenic sinusoids, capillaries, and small veins. Martel et al. (Am J Surg Pathol 28:1268-1279, 2004) suggested that SANT may represent the final pathway of a variety of splenic lesions including inflammatory pseudotumors (IPTs). Epstein-Barr virus (EBV) has a role in the genesis of some splenic IPTs, but its presence in SANT has not been investigated. Six cases of SANT are reported. All were stained for CD31, CD34, CD8, CD68, smooth muscle actin, muscle-specific actin, and CD30 and were tested for EBV by in situ hybridization (EBER). All cases showed angiomatoid nodules with complex expression of CD31, CD34, and CD8, with focal CD68. Expression of CD30 by endothelial cells was also seen. One case had small diffuse areas lacking nodules resembling an IPT and was positive for EBV. The inflammatory cells and the normal spleen were negative for CD30 and EBER. In conclusion, SANT shows upregulation of CD30 with respect to normal spleen. The presence of EBV in the stromal cells of a case supports the notion that a subset of SANT may be related to IPT.