Predominance of IgG4+ plasma cells and CD68 positivity in sclerosing angiomatoid nodular transformation (SANT)

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

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

Sclerosing angiomatoid nodular transformation of the spleen: Case reports and literature review

RATIONALE

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is an uncommon benign vascular lesion with an obscure etiology. It predominantly affects middle-aged women and presents with nonspecific clinical signs, making preoperative diagnosis challenging. The definitive diagnosis of SANT relies on pathological examination following splenectomy. This study aims to contribute to the understanding of SANT by presenting a case series and reviewing the literature to highlight the clinical presentation, diagnostic challenges, and treatment outcomes.

PATIENT CONCERNS

In this retrospective study, we analyzed the clinical data of 3 patients with confirmed SANT admitted from November 2013 to October 2023. The cases include a 25-year-old male, a 15-year-old female, and a 39-year-old male, each with a splenic mass.

DIAGNOSES AND INTERVENTIONS

All of the three cases were treated by laparoscopic splenectomy (LS). Pathological examination confirmed SANT in all cases.

OUTCOMES

No recurrence or metastasis was observed during a 10-year follow-up for the first 2 cases, and the third case showed no abnormalities at 2 months postoperatively. Despite its rarity, SANT is a significant condition due to its potential for misdiagnosis and the importance of distinguishing it from malignant lesions. The study underscores the utility of LS as a safe and effective treatment option.

LESSONS

SANT is a rare benign tumor of the spleen, and the preoperative diagnosis of whom is challenging. LS is a safe and effective treatment for SANT, with satisfactory surgical outcomes and favorable long-term prognosis on follow-up. The study contributes to the limited body of research on this rare condition and calls for larger studies to validate these findings and improve clinical management.

A case of multifocal sclerosis angiomatoid nodular transformations of the spleen occurring after partial splenic infarction with transcatheter arterial embolization for splenic artery aneurysm

A 48-year-old woman underwent transcatheter arterial embolization (TAE) for a splenic artery aneurysm, which resulted in a partial splenic infarction in the middle lobe. Five years after TAE, a 20-mm diameter mass in the noninfarcted area of the spleen was detected on imaging, which grew to 25 mm in diameter after 6 months. MRI after gadolinium administration showed a 35 × 34 mm mass within the superior pole and 15 × 12 mm mass within the inferior pole. The patient underwent laparoscopic splenectomy and had an uneventful postoperative recovery. No evidence of recurrence was observed during the 2-year follow-up period after surgery. The mass was pathologically confirmed to be sclerosing angiomatoid nodular transformation (SANT) of the spleen. While some studies hypothesize that SANT is a response to vascular injury or trauma, to the best of our knowledge, there have been no previous reports of SANT occurring after procedures directly affecting splenic blood flow. Additionally, multifocal SANTs are reported to be very rare, accounting for only 4.7% of all reported SANTs of the spleen. We highlight a rare course of SANT of the spleen and discuss the possible relationship between blood flow abnormalities and the appearance of SANT.

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 (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.

Loss of CTNNB1 exon 3 in sclerosing angiomatoid nodular transformation of the spleen

Sclerosing angiomatoid nodular transformation (SANT) is a rare vascular lesion of the spleen. Although several hypotheses have been suggested, the etiopathogenesis of SANT remains unknown. It is also unclear whether SANT is a reactive or a neoplastic lesion. Since CTNNB1 (β-catenin gene) exon 3 mutations were frequently detected in some rare fibrovascular lesions, we aimed to investigate the presence of oncogenic CTNNB1 mutations in SANT cases. For this purpose, 7 cases of SANT with typical histopathological features were retrieved. First, the presence of CTNNB1 exon 3 alterations was examined with a recently described immunohistochemistry-based method. Then, the findings were confirmed with polymerase chain reaction (PCR), reverse transcription PCR (RT-PCR), and Sanger sequencing. In all cases, immunochemistry of β-catenin gave a staining pattern that was suggestive of exon 3 alteration; however, no missense mutations were found in any case at the CTNNB1 exon 3 hotspot region. Subsequently, we screened for large interstitial deletions of CTNNB1 exon 3 which revealed short PCR products in three cases. Sequencing confirmed that these cases had large interstitial deletions, resulting in loss of the entire exon 3 of CTNNB1. In the remaining four cases, loss of exon 3 was documented at the cDNA level, although genomic deletion was not identified. These results demonstrate that loss of CTNNB1 exon 3 and stabilization of β-catenin with activation of Wnt signaling pathway might have a significant role in the pathogenesis of SANT. Through this study, we provided important evidence for the neoplastic nature and pathogenesis of this disorder.

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.

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: Lessons from a Rare Case and Review of the Literature

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

Sclerosing Angiomatoid Nodular Transformation of the Adrenal Gland: A Case Report of a Novel Histopathological Entity

The finding of an indeterminate adrenal mass at radiological investigations is a challenge for physicians. Complex diagnostic work-up, periodic follow-up, or surgical intervention are therefore needed to rule out malignant lesions. Tertiary care hospitals are provided with ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and ¹⁸F-dihydroxyphenylalanine (¹⁸F-DOPA) PET, which aid in the characterization of indeterminate adrenal masses. Nevertheless, the histopathological examination may be required to exclude malignancy or rare etiologies. A 54-year-old woman presented to our clinic 6 months after a cerebral hemorrhage. She was hypertensive and had recently discovered a left adrenal mass of 15 mm during an abdominal ultrasound. Contrast-enhanced CT, following adrenal protocol, revealed a 14-mm adrenal mass without characteristics suggestive of an adrenal adenoma. Tumor markers were negative. Functional tests excluded hormone hypersecretion. An ¹⁸F-DOPA PET was negative. An ¹⁸F-FDG PET showed mild uptake of both the adrenal glands, with a more circumscribed pattern in the left one (maximum standardized uptake value = 4). As the clinical diagnosis was still indeterminate, we performed laparoscopic left adrenalectomy. The histopathological examination described a sclerosing angiomatoid nodular transformation (SANT) of the adrenal gland, a benign lesion already described as a rare occurrence only in the spleen. IgG4 levels were reduced. In conclusion, this is a report of a SANT of the adrenal gland, a novel entity that should be taken into consideration in the differential diagnosis of indeterminate adrenal masses at CT scan.

Sclerosing angiomatoid nodular transformation in the spleen: A case series study and literature review

To assess the clinicopathologic features, differential diagnosis, and pathogenesis of sclerosing angiomatoid nodular transformation (SANT) of the spleen.The clinical characteristics of 7 cases with SANT were retrospectively analyzed. Histochemical and immunohistochemical (EnVision method) examinations were performed. Moreover, quantitative assessment of IgG4 and IgG-positive cells was performed.The 7 SANT patients included 1 female and 6 males, with ages ranging from 7 to 60 years (mean 33.4 years). They showed no specific clinical manifestations. Macroscopically, the surface of the excised masses was gray-white, and vague nodularity was observed. Mass sizes ranged from 3.0 to 7.0 cm (mean 5.5 cm). Microscopically, all cases were characterized based on multiple angiomatoid nodules of various sizes embedded in a fibrosclerotic stroma. The nodules were round and sometimes convoluted. Moreover, the nodules were composed of slit-like, irregularly-shaped, or slightly dilated vascular spaces lined by plump endothelial cells, and interspersed with a population of spindly or ovoid cells. Immunohistochemical examination showed a heterogeneous staining pattern, with the lining cells of small capillaries expressing CD34 and those of sinusoid-like structures expressing CD8. CD31 was stained in the lining and interspersed cells, thus resulting in a complex meshwork. Additionally, the lining cells were focally positive for CD68. Vimentin and smooth muscle antibody were expressed in all 7 cases, whereas no desmin or CD21 was detected. IgG4-positive cells accounted for 2 to 5 per high-power field (mean 3.7). Furthermore, the IgG-positive cells accounted for 2 to 8 per high-power field (mean 4.2).SANT is a rare primary benign tumor-like lesion of the spleen, and has characteristic histopathological features and immunohistochemical profiles. SANT should be distinguished from other angiomatoid tumors and tumor-like lesions. Moreover, SANT could be treated by splenectomy, with favorable prognosis. The relationship between SANT and IgG4-related sclerosing lesions remains to be clarified.

Gastric calcifying fibrous tumor: A clinicopathological study of nine cases

The aim of the present study was to analyze the clinicopathological characteristics presented in 9 cases of gastric calcifying fibrous tumor (CFT), and investigate the expressions and clinical implications of G protein-coupled estrogen receptor (GPER), estrogen receptor (ER) and vimentin in gastric CFTs. The clinical and pathological information of 9 patients with CFTs was investigated retrospectively. Subsequently, the expression of GPER, ER and vimentin were examined using immunohistochemistry, and a literature search for gastric CFT was conducted. The 9 patients were 40–71 years old with a mean age of 52.22 years, including 6 female and 3 male patients. Pathological features included dense hyalinized collagen fibers with a psammomatous body or dystrophic calcification, and the infiltration of scattered lymphocytes and plasma cells. Immunohistochemically, all cases expressed vimentin and GPER, whereas ER expression was negative. Using a database research, 25 studies regarding gastric CFT were identified, including 48 cases with a sex ratio (female:male) of 1.4:1. In addition, the number of female patients was twice the number of male patients in patients <50 years old, whereas the number was almost equal between women and men ≥50 years of age. Gastric CFT is a benign lesion with a good prognosis and a predilection for female patients, particularly premenopausal women. Estrogen may serve a role in this female predominance, and this may be mediated by GPER rather than ER.

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.

Polyclonality in Sclerosing Angiomatoid Nodular Transformation of the Spleen

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a morphologically distinctive lesion. Although the clinical course of SANT is benign, its reactive or neoplastic nature remains to be clarified. Furthermore, some investigators have suggested that SANT is related to IgG4 sclerosing lesion or inflammatory pseudotumor with stromal cells positive for Epstein-Barr virus (EBV). In this study, we assessed 22 cases of SANT derived from adult women. Clinical data and follow-up information were obtained by chart review. Immunohistochemical studies for IgG4, IgG, and CD21 stains and in situ hybridization to detect EBV-encoded small RNAs were performed. We also assessed genomic DNA extracted from paraffin-embedded tissue for human androgen-receptor α gene analysis using conventional and methylation-specific polymerase chain reaction methods. The median patient age was 41.5 years (range, 25 to 82 y). Most (77%) patients presented with a single mass that was detected incidentally (59%). The mean size of the lesions was 3.8 cm (range, 1.0 to 9.0 cm). Clinical symptoms correlated with multiple lesions (P=0.043) but not lesional size (P=0.637) or location in the spleen (hilum vs. periphery, P=0.696). None of the cases had evidence of IgG4-related disease or recurred after splenectomy. The mean number of IgG4 cells was 27.7 (range, 4 to 125), and the mean IgG4/IgG ratio was 16.4% (range, 1.6% to 55.7%) with only 2 cases being >40%. Cases with higher IgG4 cells did not correlate with inflammatory pseudotumor-like morphology. No lesions were positive for EBV-encoded small RNAs, and almost all cases with informative results (n=19) showed a polyclonal pattern. We conclude that SANT is a polyclonal, reactive lesion rather than a neoplasm.

Sclerosing angiomatoid nodular transformation of the spleen presenting rapid growth after adrenalectomy: Report of a case

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SANT displayed a rapid growth in size from 20 mm to 70 mm during 3 years after adrenalectomy.

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Splenectomy was performed by hand assisted laparoscopic surgery (HALS).

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Corticosteroids might be useful for treating SANT.

Introduction

Sclerosing angiomatoid nodular transformation (SANT) is a rare benign lesion with an unknown natural history and pathogenesis. So far fewer than 100 cases were documented, but detailed incidence and prevalence are unknown.

Presentation of case

We report a case of SANT of the spleen in a 37-year-old man that showed rapid growth after adrenalectomy for primary aldosteronism. Computed tomography showed a nodule in the spleen that increased in size from 2.0 cm to 7.0 cm during 3 years of observation.

Discussion

This case is reported because data regarding growth rates and natural history of these lesions are limited and few cases have been reported to show the rapid growth progression seen in this case.

Conclusion

Decreases in glucocorticoid concentrations following adrenalectomy may have contributed to the rapid growth of SANT of the spleen, because SANT is considered to be related to immunoglobulin G4-associated disease.

Sclerosing Angiomatoid Nodular Transformation of the spleen, focal nodular hyperplasia and hemangioma of the liver: A tale of three lesions

Sclerosing Angiomatoid Nodular Transformation (SANT) of the spleen is a benign vascular lesion with peculiar histological features. The pathogenesis of SANT is still largely unknown and variable etiologies have been proposed, including autoimmune, inflammatory, and/or vascular disorders. The present report describes a unique case of splenic SANT, associated with focal nodular hyperplasia and a sclerosing hemangioma of the liver. The clinic-pathological features of such an unusual case are thoroughly illustrated. Its possible pathogenic mechanisms are also briefly addressed.

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.

Laparoscopic and Percutaneous Core Needle Biopsy Plays a Central Role for the Diagnosis of Autoimmune Pancreatitis in a Single-Center Study From Denmark

OBJECTIVES

The aims of this study were to describe the diagnosis of autoimmune pancreatitis (AIP) in Denmark and to test the usefulness of the International Consensus Diagnostic Criteria (ICDC) on a geographically well-defined cohort.

METHODS

All patients diagnosed with AIP at Odense University Hospital from 2007 to 2013 were included (n = 30; mean follow-up, 26.2 months). Data from laparoscopic or percutaneous ultrasound-guided core needle biopsy (CNB), resection specimens, endoscopic ultrasound (EUS), EUS-guided CNB, computed tomography, serum immunoglobulin G4 (IgG4), and pancreatography were retrospectively analyzed according to ICDC.

RESULTS

Twenty patients were diagnosed with type 1, 8 with type 2, and 2 with not otherwise specified AIP. Twenty-eight patients (93%) could correctly be classified when ICDC were retrospectively applied. Serum IgG4 was elevated in 44% of type 1 and 0% of type 2. Other organ involvement was observed in 40% of type 1 and 13% of type 2, but inflammatory bowel disease only in type 2 (P = 0.001). One patient had IgG4-related chronic perisplenitis as a hitherto undescribed manifestation of IgG4-related disease. Nineteen (91%) of 21 biopsied patients had diagnostic CNB features of AIP. Computed tomography, EUS, and pancreatography showed features highly suggestive or supportive of AIP in 68%, 72%, and 71%, respectively.

CONCLUSIONS

Laparoscopic or percutaneous ultrasound-guided CNB had the highest sensitivity for AIP. The ICDC could retrospectively correctly diagnose 93% of the patients.

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.

A case of cord capillary hemangioma of the spleen: a recently proven true neoplasm

Cord capillary hemangioma (CCH) of the spleen is an extremely rare lesion. Once classified under splenic hamartoma, CCH is now differentiated from hamartoma, as its clonality has recently been proven. Herein, we present the case of an incidentally found CCH, measuring 6 × 5.5 × 5 cm, in a 45-year-old man. He underwent splenectomy and has been recurrence-free for 8 years. Macroscopically, the cut surface of the mass showed a central stellate scar with peripheral interspersed reddish areas of variable sizes and intervening fibrous bands. Microscopically, the mass was well demarcated from the splenic tissue. The macroscopic reddish areas were found to correspond to nodules of various sizes, which were predominantly composed of CD34-expressing capillaries without the presence of CD8-expressing sinuses. The relative proportion of these two types of vessels distinguishes CCH from sclerosing angiomatoid nodular transformation (SANT), as SANT shows the apparent presence of CD8-expressing sinuses. In longstanding cases of SANT, sinuses might become ambiguous and the differences between CCH and SANT might become subtle. Nonetheless, immunohistochemistry should be performed when these conditions are suspected, since accurate distinction is usually achieved as a result.

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 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 (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.

The latest on IgG4-RD: a rapidly emerging disease

PURPOSE OF REVIEW

Provide an update of the developments in IgG4 related disease within the last year in terms of nomenclature, diagnostic criteria and clinical features.

RECENT FINDINGS

The number of diseases associated with IgG4 related disease continues to grow. The entities of idiopathic orbital inflammation, idiopathic cervical fibrosis, eosinophilic angiocentric fibrosis, reactive nodular fibrous pseudotumor, sclerosing mesenteritis, and membranous glomerulonephritis should all be added to the list of diseases associated with the IgG4 related disease spectrum. The issues of nomenclature and diagnostic criteria for IgG4 related disease have important recent developments as well.

SUMMARY

The diagnosis of IgG4 related disease continues to be challenging. Increasing recognition of IgG4 related disease has led to a large body of literature on organ sites of involvement. Understanding how the disease manifests itself is critical to diagnosis and ultimately treatment.

IgG4-related sclerosing disease, an emerging entity: a review of a multi-system disease

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently defined emerging entity characterized by a diffuse or mass forming inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosclerosis and obliterative phlebitis. IgG4-RSD usually affects middle aged and elderly patients, with a male predominance. It is associated with an elevated serum titer of IgG4, which acts as a marker for this recently characterized entity. The prototype is IgG4-related sclerosing pancreatitis or autoimmune pancreatitis (AIP). Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, however practically any organ can be involved, including upper aerodigestive tract, lung, aorta, mediastinum, retroperitoneum, soft tissue, skin, central nervous system, breast, kidney, and prostate. Fever or constitutional symptoms usually do not comprise part of the clinical picture. Laboratory findings detected include raised serum globulin, IgG and IgG4. An association with autoantibody detection (such as antinuclear antibodies and rheumatoid factor) is seen in some cases. Steroid therapy comprises the mainstay of treatment. Disease progression with involvement of multiple organ-sites may be encountered in a subset of cases and may follow a relapsing-remitting course. The principal histopathologic findings in several extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, along with atrophy and destruction of tissues. Immunohistochemical staining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). IgG4-RSD may potentially be rarely associated with the development of lymphoma and carcinoma. However, the nature and pathogenesis of IgG4-RSD are yet to be fully elucidated and provide immense scope for further studies.

Clonal X-chromosome inactivation suggests that splenic cord capillary hemangioma is a true neoplasm and not a subtype of splenic hamartoma

Splenic hamartoma is a rare tumor-like lesion composed of structurally disorganized red pulp elements. It has been hypothesized that two other splenic lesions, cord capillary hemangioma and myoid angioendothelioma, may fall within the spectrum of splenic hamartoma, simply representing morphological variants. In this study, we compared the vascular and stromal composition of cord capillary hemangioma and myoid angioendothelioma with those of classical hamartoma. In addition, we assessed the clonal vs polyclonal nature of the lesions in nine female cases by performing clonality analysis for X-chromosome inactivation at the human androgen receptor locus (HUMARA) on laser-assisted microdissected samples. In 15 of 17 cases, increased reticulin and/or collagen content was observed. The classical hamartoma cases showed a vasculature predominantly composed of CD8+ CD31+ CD34- splenic sinuses, whereas cases of cord capillary hemangioma and myoid angioendothelioma contained many CD8- CD31+ CD34+ cord capillaries, but very little CD8+ vasculature. All cases lacked expression of D2-40 and Epstein Barr virus-encoded RNA. All cases showed a proliferation index of ≤5% by Ki-67. Cases of classical hamartoma lacked significant perisinusoidal expression of collagen IV and low-affinity nerve growth factor receptor. Both markers were variably expressed in the other lesions. Increased CD163-positive histiocytes were found in four cases (three cord capillary hemangiomas and one myoid angioendothelioma). HUMARA analysis was informative in all nine tested cases, of which three cases showed a non-random X-chromosome inactivation pattern, indicating clonality. All three clonal cases were cord capillary hemangiomas. Our study has shown that in spite of considerable morphologic heterogeneity and overlapping features, classical hamartoma and cord capillary hemangioma and myoid angioendothelioma are different in terms of their vascular and stromal composition. Clonality analysis supports a true neoplastic origin for the cord capillary hemangioma. A larger study using additional immunohistochemical and molecular studies is necessary to further evaluate the biological significance of the current findings.

IgG4-related sclerosing disease: a critical appraisal of an evolving clinicopathologic entity

An elevated serum titer of immunoglobulin G4 (IgG4), the least common (3% to 6%) of the 4 subclasses of IgG, is a surrogate marker for the recently characterized IgG4-related sclerosing disease. The syndrome affects predominantly middle-aged and elderly patients, with male predominance. The patients present with symptoms referable to the involvement of 1 or more sites, usually in the form of mass lesions. The prototype is IgG4-related sclerosing pancreatitis (also known as autoimmune pancreatitis), most commonly presenting as painless obstructive jaundice with or without a pancreatic mass. Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, but practically any organ-site can be affected, such as retroperitoneum, aorta, mediastinum, soft tissue, skin, central nervous system, breast, kidney, prostate, upper aerodigestive tract, and lung. The patients usually have a good general condition, with no fever or constitutional symptoms. Common laboratory findings include raised serum globulin, IgG, IgG4, and IgE, whereas lactate dehydrogenase is usually not raised. Some patients have low titers of autoantibodies (such as antinuclear antibodies and rheumatoid factor). The disease often shows excellent response to steroid therapy. The natural history is characterized by the development of multiple sites of involvement with time, sometimes after many years. However, the disease can remain localized to 1 site in occasional patients. The main pathologic findings in various extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, accompanied by atrophy and loss of the specialized structures of the involved tissue (such as secretory acini in pancreas, salivary gland, or lacrimal gland). The relative predominance of the lymphoplasmacytic and sclerotic components results in 3 histologic patterns: pseudolymphomatous, mixed, and sclerosing. Immunostaining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). The lymph nodes show multicentric Castleman disease-like features, reactive follicular hyperplasia, interfollicular expansion, or progressive transformation of germinal centers, with the unifying feature being an increase in IgG4+ plasma cells on immunostaining. The nature and pathogenesis of IgG4-related sclerosing disease are still elusive. Occasionally, the disease can be complicated by the development of malignant lymphoma and possibly carcinoma.

Sclerosing angiomatoid nodular transformation of the spleen in an adolescent with chronic abdominal pain

Sclerosing angiomatoid nodular transformation (SANT) is a relatively new, benign neoplasm arising within the red pulp of the spleen. The lesion is often identified incidentally on imaging, and the diagnosis is confirmed on pathologic assessment of the resected spleen. Although there have been several reports of SANT in the adult population, data on this lesion in the pediatric population are exceedingly rare. We present a case of SANT in an adolescent male with chronic abdominal pain and discuss the management issues that arise in treating this condition in the pediatric population.

Sclerosing angiomatoid nodular transformation of the spleen (SANT): clinicopathological study of 10 cases with or without abdominal disseminated calcifying fibrous tumors, and the presence of a significant number of IgG4+ plasma cells

Sclerosing angiomatoid nodular transformation (SANT) is a peculiar splenic vascular lesion that is characterized by marked stromal sclerosis and the presence of plasma cells, which shares histopathological features associated with IgG4-related sclerosing disease. The cinicopathological features of 10 cases of SANT were reviewed and immunohistochemistry with IgG4 and IgG antibodies was performed. Nine other various splenic lesions served as controls. Five cases of SANT were found incidentally. Three cases of SANT had multiple tumors and five had associated abdominal disseminated calcifying fibrous tumors (CFT). IgG4+ plasma cells were found in all of the cases of SANT and in calcifying fibrous tumors. The densities of IgG4+ and IgG+ cells and the IgG4/IgG ratios were significantly higher in SANT than in control spleens (P= 0.001, 0.006, and 0.028, respectively). Serum IgG4 concentration was elevated in one case. In conclusion, SANT can occur either as a solitary or as multiple tumors. Frequent association with abdominal disseminated CFT simulating carcinomatosis was observed. A statistically significant number of IgG4+ plasma cells was found in all of the cases of SANT and the associated CFT. Whether they are related to the IgG4-related sclerosing disease or not is debatable and warrants further investigation.

Calcifying fibrous tumor of the stomach: clinicopathologic and molecular study of seven cases with literature review and reappraisal of histogenesis

Calcifying fibrous tumor (CFT) is a rare benign mesenchymal tumor composed of hyalinized fibrous tissue with interspersed bland fibroblastic spindled cells, scattered psammomatous, and/or dystrophic calcifications and variably prominent mononuclear inflammatory infiltrate. CFTs show a predilection for the abdominal cavity and soft tissue. To date, 6 gastric and 3 intestinal CFTs have been reported. We analyzed 7 gastric CFTs including 6 new cases. Patients were 4 men and 3 women with a mean age of 53 years (range, 40 to 77). Mean tumor size was 2.2 cm. Most tumors originated in the gastric body (6/7). Six were incidental findings at autopsy or during surgery for other diseases. One ulcerated tumor caused iron deficiency anemia and ulcer symptoms. Six tumors involved the muscularis propria with variable submucosal and subserosal extension and 1 arose within thickened muscularis mucosae adjacent to a mucosal invagination. Histology was typical with uniformly hypocellular vaguely storiform collagen, lymphoplasmacytic infiltrates, lymphoid aggregates and psammomatous, and dystrophic calcifications. Peritumoral lymphoid aggregates were seen in 3 cases. Adjacent muscle coat contained lymphoid aggregates with fiber degeneration (2), minute CFT-like foci (1), and calcifications (1). In none of the cases were there remnants of burnt-out GIST, inflammatory fibroid polyp, inflammatory myofibroblastic tumor, leiomyoma, schwannoma, or other specific lesion. All tumors were negative for CD117, S100, smooth muscle actin, desmin, ALK1, h-caldesmon, and PDGFRA. Two stained focally with CD34. Scattered IgG4-positive plasma cells were seen in 4 of 6 cases stained with this marker. All 5 tumors with available tissue for molecular analysis were wild-type for KIT and PDGFRA. Three patients had follow-up (range, 12 to 24 mo); none developed recurrence. Gastric CFTs are distinct from sclerosing GIST and other mesenchymal gut lesions and may represent a localized inflammatory fibrosclerosis in response to immune-mediated or other-type tissue injury affecting the muscularis propria. They differ from soft tissue CFTs by smaller size, older age at presentation and lack of recurrence, and from peritoneal CFTs by equal gender distribution, older age, and absent multifocal occurrence.

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.