Distinctive PET/CT features of splenic SANT. Feng Yu-Min,Huang Ying Chieh,Tu Chi-Wen,Kao Wen-Shih,Tu Dom-Gene Clinical nuclear medicine A 44-year-old woman suffered from epigastralgia for 1 month. An abdominal sonography revealed a space-occupying lesion, about 6 cm, in the spleen. Contrast-enhanced CT revealed enhanced splenic lesions. The PET/CT showed FDG-avid multiple splenic nodules with a "prunes on bread" appearance in the maximum-intensity-projection image (MIP image). In sectional PET/CT images, a central cold area with peripheral increased FDG uptake in the splenic nodule is visible. Because splenic malignancy was suspected, laparoscopic splenectomy was performed. Histology revealed multiple nodules with angiomatoid appearance, CD31(+), CD34(+) and HHV-8(-) in the vascular space, typical for the rare sclerosing angiomatoid nodular transformation (SANT). 10.1097/RLU.0b013e3182867581
    Sclerosing angiomatoid nodular transformation of the spleen. A case report. Martínez Martínez Pedro Jesús,Solbes Vila Ramón,Bosquet Úbeda Carlos Javier,Roig Álvaro José María Revista espanola de enfermedades digestivas : organo oficial de la Sociedad Espanola de Patologia Digestiva A 57 year old woman presenting with heartburn and a one month history of epigastric abdominal pain and left hypochondrium pain. After conducting an ultrasound scan and a CT scan, a low attenuation lesion in the spleen was found, and the definitive diagnosis was sclerosing angiomatoid nodular transformation of the spleen (STANT) which was based on a splenectomy and a pathologic study. SANT is a benign rare vascular disease consisting of proliferation of angiomatoid/vascular nodules which predominantly affects women aged 27 to 68. It is usually detected as a coincidental finding in asymptomatic patients. The presumptive diagnosis is established by imaging tests, especially CT and MR; and the final diagnosis is as well established on the basis of pathology after a splenectomy.
    Sclerosing Angiomatoid Nodular Transformation of the Spleen: Lessons from a Rare Case and Review of the Literature. Nomura Ryohei,Tokumura Hiromi,Katayose Yu,Nakayama Fumie,Iwama Noriyuki,Furihata Makoto Internal medicine (Tokyo, Japan) 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. 10.2169/internalmedicine.1948-18
    18F-FDG avid Sclerosing Angiomatoid Nodular Transformation (SANT) of spleen on PET-CT - a rare mimicker of metastasis. Sharma Punit Nuclear medicine review. Central & Eastern Europe Sclerosing Angiomatoid Nodular Transformation (SANT) is a rare benign vascular tumor of spleen. It consists of multiple angiomatoid nodules surrounded by dense fibrous tissue that often coalesces centrally to form a scar, which is considered to be a characteristic feature. These are usually asymptomatic and incidentally detected on imaging for other underlying pathology. SANTs can be 18F-Fluorodeoxyglucose (18F-FDG) avid on positron emission tomography-computed tomography (PET-CT) and thus can lead to false positive finding in oncological patients. 10.5603/NMR.2018.0014
    An unusual case of sclerosing angiomatoid nodular transformation: radiological and histopathological analyses. Metin Melike Ruşen,Evrimler Sehnaz,Çay Nurdan,Çetin Hüseyin Turkish journal of medical sciences Sclerosing angiomatoid nodular transformation (SANT) is a rare benign primary vascular lesion of the spleen. Its etiology is still debated. Radiological characteristics are less known, although there are some reports regarding histopathological features ofSANT. A 21-year-old male patient was admitted to our hospital with fatigue, weight loss, and abdominal pain for 4 months. Physical examination, complete blood count, andbiochemical parameters were unremarkable. Dynamic contrast-enhanced computed tomography (CT) of the abdomen was performed. A heterogeneous well-defined hyperdense nodular lesion 3 cm in diameter was detected during the arterial phase. The detected lesion was seen as isodense with the spleen parenchyma during the portal venous and late venous phases. Magnetic resonance imaging (MRI) showed an isointense-hypointense nodular lesion on T1- and T2-weighted images. Intraabdominal LAM or splenomegaly was not detected. Microscopically, it was composed of angiomatoid nodules separated by central stellate fibrous stroma and fibrous septa. The contrast enhancement pattern was described as centrally hypovascular, radially progressive centripetal vascular contrast enhancement, called a spoke-wheel pattern in previously reported cases. We present CT and MRI findings and their correlation with histopathological findings of a case of unusual symptomatic SANT.
    Multifocal sclerosing angiomatoid nodular transformation of the spleen in a patient with simultaneous metachronous liver metastasis after colon cancer surgery: a first case report. Mueller A K,Haane C,Lindner K,Barth P J,Senninger N,Hummel R Pathologica Sclerosing angiomatoid nodular transformation of the spleen (SANT) is a benign, extremely rare vascular lesion of the spleen with unknown pathogenesis. SANT is often discovered incidentally, and can sometimes be found in patients with a history of cancer. Based on absent definitive radiological signs and varying growth patterns, distinction from malignant processes such as metastasis can be very difficult. Therefore, surgical resection of the spleen is indicated in most cases of patients with history of cancer. We report a case of a bifocal manifestation of SANT in the spleen in a patient with history of colon cancer and newly-diagnosed metachronous liver metastases.
    A case of cord capillary hemangioma of the spleen: a recently proven true neoplasm. Tajima Shogo,Koda Kenji Pathology international 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. 10.1111/pin.12277
    Sclerosing angiomatoid nodular transformation of the spleen during pregnancy: Diagnostic challenges and clinical management. Corrado Giacomo,Tabanelli Valentina,Biffi Roberto,Petralia Giuseppe,Tinelli Andrea,Peccatori Fedro A The journal of obstetrics and gynaecology research 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. 10.1111/jog.13008
    Sclerosing angiomatoid nodular transformation of the accessory spleen: A case report and review of literature. Niu Miao,Liu Ailian,Wu Jingjun,Zhang Qinhe,Liu Jinghong Medicine RATIONALE:Sclerosing angiomatoid nodular transformation (SANT) is a rare case which usually occurs in spleen, but our case occurs in accessory spleen. PATIENT CONCERNS:We reported a case of a 27 year old man who was identified with an isodense mass in the left abdominal cavity by ultrasonicphysical examination without symptoms. Blood routine and tumor markers (alpha fetal protein, carcinoembryonic antigen, CA19-9, CA125) were normal. DIAGNOSES:The tumor was firstly diagnosed as left abdominal mass and its origin was considered as small intestinal by the radiologist. The pathological diagnosis was the sclerosing angiomatoid nodular transformation (SANT) of the accessory spleen. INTERVENTIONS:Laparoscopic splenectomy is a more reliable method for the treatment of SANT. OUTCOMES:Non-enhanced CT showed iso-intensity lesion of the accessory spleen, and enhanced CT showed progressive enhancement. According to the above characteristics, we should consider the diagnosis of spleen SANT. We reviewed some literatures to summarize the characteristics of SANT. 10.1097/MD.0000000000011099
    Imaging Features of Sclerosing Angiomatoid Nodular Transformation in Spleen. Ma Jianbing,Zhang Weiqiang,Wang Lizhang,Zhu Zefeng,Wang Jia,Zhang Jingfeng,Yang Xiaofeng Journal of computer assisted tomography PURPOSE: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). MATERIALS AND METHODS:From July 2006 to April 2017, 12 patients with SANT confirmed by pathology were evaluated in a retrospective study. Eight patients were with CT imaging only, 2 patients were with MR imaging only, and 2 patients were with both CT and MR. Three professional senior radiologists analyzed the imaging features on CT and MR. The main characteristic analysis included size, margin, density, signal intensity, and enhancement pattern. The significant enhancement was defined as the degree of enhancement of lesion that is higher than the surrounding spleen parenchyma, and the mild enhancement was defined as the degree of enhancement of lesion that is lower than the surrounding spleen parenchyma. RESULTS:All the 12 patients (5 men, 7 women; mean age, 45.8 years; age range, 21-62 years) presented as single lesion without special clinical symptoms. The range of lesions on diameter was from 25 to 80 mm. On CT images, 9 (90%) of 10 presented as hypodense in comparison with the parenchyma of spleen, 1 (10%) of 10 presented as isodense, and calcification was observed in 4 (40%) of 10 cases. On MR images, 4 (100%) of 4 manifested heterogeneous hypointensity on in-phase sequence and 3 (75%) of 4 performed as isointensity on out-of-phase sequence of T1-weighted. On the sequences of T2-weighted and diffusion-weighted image, 4 (100%) of 4 showed hypointensity. On CT and MR enhancement images, the number of significant enhancement and mild enhancement was 2 and 10, respectively. Seven (58%) of 12 showed progressive enhancement with the pattern of "spoke-wheel." CONCLUSIONS:Imaging features on CT and MR have a high diagnostic value for SANT, especially when CT combined with MR examination. 10.1097/RCT.0000000000000910
    Sclerosing angiomatoid nodular transformation of the spleen related to IgG4-associated disease: report of a case. Kim Ho-Hyun,Hur Young-Hoe,Koh Yang-Seok,Kim Jung-Chul,Kim Hyun-Jong,Kim Jin-Woong,Kim Young,Lee Jae-Hyuk,Cho Chol-Kyoon Surgery today 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. 10.1007/s00595-013-0499-3
    Sclerosing angiomatoid nodular transformation of the spleen (SANT) in a patient with clear cell carcinoma of the uterus: a case report. Efared Boubacar,Sidibé Ibrahim S,Erregad Fatimazahra,Hammas Nawal,Chbani Laila,El Fatemi Hinde Journal of medical case reports BACKGROUND:Sclerosing angiomatoid nodular transformation of the spleen is a very rare benign vascular lesion recently described. Usually, sclerosing angiomatoid nodular transformation of the spleen is an incidental finding; the association with malignant tumors is extremely rare. To the best of our knowledge, we report the first case of sclerosing angiomatoid nodular transformation of the spleen associated with uterine clear cell carcinoma. CASE PRESENTATION:A 49-year-old Arabic woman presented to our institute with abdominal pain and distention. An abdominal computed tomographic scan was obtained, which showed a 14-cm uterine malignant tumor and a 4-cm isolated splenic nodule suggesting a metastatic lesion. The tumor was limited to the uterus but did not extend beyond. The patient underwent surgical treatment, and the histopathological examination of the resected uterine and splenic specimens disclosed invasive uterine clear cell carcinoma and sclerosing angiomatoid nodular transformation of the spleen, respectively. The patient had no signs of the disease 17 months after surgical treatment. CONCLUSIONS:Sclerosing angiomatoid nodular transformation of the spleen is a very rare benign disease with a misleading presentation when associated with a malignant tumor. Pathological assessment of the resected spleen is the only way to achieve the correct diagnosis. 10.1186/s13256-018-1907-5
    Sclerosing angiomatoid nodular transformation of the spleen mimicking metastasis of melanoma: a case report and review of the literature. Demirci Ilhan,Kinkel Horst,Antoine Dirk,Szynaka Marc,Klosterhalfen Bernd,Herold Susanne,Janßen Hermann Journal of medical case reports 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. 10.1186/s13256-017-1400-6
    Hand-assisted laparoscopic splenectomy for sclerosing angiomatoid nodular transformation of the spleen complicated by chronic disseminated intravascular coagulation: a case report. Kakisaka Tatsuhiko,Kamiyama Toshiya,Yokoo Hideki,Orimo Tatsuya,Wakayama Kenji,Tsuruga Yosuke,Kamachi Hirofumi,Harada Taisuke,Kato Fumi,Yamada Yosuke,Mitsuhashi Tomoko,Taketomi Akinobu Asian journal of endoscopic surgery A 36-year-old man who presented with a nosebleed and anemia was referred to our hospital. Laboratory test results showed platelet depletion, decreased levels of fibrinogen, and increased fibrinogen degeneration products. CT showed a 13-cm splenic tumor. T2 -weighted MRI revealed a high-intensity mass. We preoperatively diagnosed splenic hemangioma with chronic disseminated intravascular coagulation and scheduled an operation to relieve the disseminated intravascular coagulation. We also performed hand-assisted laparoscopic splenectomy to ensure easy handling of the splenomegaly. The resected specimen microscopically consisted of hemorrhages and hemangiomatous lesions, and multiple angiomatoid nodules were scattered and separated by fibrocollagenous stroma with inflammatory cells. Three types of vessels (capillaries, sinusoids and small veins) were contained in the angiomatoid nodules, and the pathological diagnosis was sclerosing angiomatoid nodular transformation. The results of this case suggest that we should consider sclerosing angiomatoid nodular transformation in the differential diagnosis of patients with splenic tumors, as sclerosing angiomatoid nodular transformation with hemangiomatous features may cause coagulation disorders for which splenectomy should be performed. 10.1111/ases.12116
    Sclerosing Angiomatoid Nodular Transformation of the spleen, focal nodular hyperplasia and hemangioma of the liver: A tale of three lesions. Cafferata Barbara,Pizzi Marco,D'Amico Francesco,Mescoli Claudia,Alaggio Rita Pathology, research and practice 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. 10.1016/j.prp.2016.07.003
    Sclerosing angiomatoid nodular transformation of the spleen in a patient with Maffucci syndrome: a case report and review of literature. Huang Xiao-Dan,Jiao Hao-Sen,Yang Zheng,Chen Chuang-Qi,He Yu-Long,Zhang Xin-Hua Diagnostic pathology BACKGROUND:Maffucci syndrome is a congenital, non-hereditary mesodermal dysplasia characterized by multiple enchondromas and hemangiomas. The presence of visceral vascular lesions in this syndrome is exceedingly rare. CASE PRESENTATION:We report a 26-year-old female who was diagnosed with Maffucci syndrome along with sclerosing angiomatoid nodular transformation (SANT) of the spleen. The patient underwent a laparoscopic splenectomy. Immunostaining of the excised specimen revealed 3 distinct types of vessels in the angiomatoid nodules: CD34-/CD8-/CD31+ small veins, CD34-/CD8+/CD31+ sinusoids, and CD34+/CD8-/CD31+ capillaries, leading to the diagnosis of SANT of the spleen. CONCLUSIONS:This case reports the first patient in the literature exhibiting the features of Maffucci syndrome along with SANT of the spleen. The spleen is probably a predilection site of visceral vascular lesions in this syndrome with a proportion of 4 out of 14. An abdominal Computed Tomography (CT) scan is recommended for any cases of abdominal discomfort. Surgical excision is usually sufficient because of the relatively benign behavior of SANT, however, a more aggressive follow-up is proposed due to the high risk of malignant transformation of enchondromas and development of other neoplasms associated with this syndrome. Further studies are required to reveal its genetic basis for comprehensive prognosis evaluation and therapeutic guidance. 10.1186/s13000-017-0670-z
    Sclerosing angiomatoid nodular transformation (SANT): report of 25 cases of a distinctive benign splenic lesion. Martel Maritza,Cheuk Wah,Lombardi Luciano,Lifschitz-Mercer Beatriz,Chan John K C,Rosai Juan The American journal of surgical pathology Twenty-five cases of a morphologically distinctive vascular lesion of the spleen are described. The patients were 17 women and 8 men, ranging in age from 22 to 74 years (mean, 48.4 years; median, 56 years). The most common presentations were incidental finding of an asymptomatic splenic mass (13 patients), abdominal pain or discomfort (6 patients), and splenomegaly (4 patients). None of the patients had evidence of recurrent disease after splenectomy. The splenic lesion was solitary, measuring 3 to 17 cm, and sharply demarcated from the surrounding parenchyma. The cut surface revealed a mass of coalescing red-brown nodules embedded in a dense fibrous stroma. All cases showed a remarkably consistent multinodular appearance at low-power examination. The individual nodules had an angiomatoid appearance, in the sense that they were composed of slit-like, round or irregular-shaped vascular spaces lined by plump endothelial cells and interspersed by a population of spindly or ovoid cells. Some of the nodules (particularly the smaller ones) were surrounded by concentric rings of collagen fibers. Numerous red blood cells were present, as well as scattered inflammatory cells. Nuclear atypia was minimal, mitotic figures were extremely rare, and necrosis was consistently absent. The internodular stroma consisted of variably myxoid to dense fibrous tissue with scattered plump myofibroblasts, plasma cells, lymphocytes, and siderophages. Immunostaining revealed 3 distinct types of vessels in the angiomatoid nodules: CD34+/CD8-/CD31+ capillaries, CD34-/CD8+/CD31+ sinusoids, and CD34-/CD8-/CD31+ small veins, recapitulating the composition of the normal splenic red pulp. These features are therefore different from those of littoral cell angioma, conventional hemangioma, and hemangioendothelioma of the spleen. We interpret these angiomatoid nodules as altered red pulp tissue that had been entrapped by a nonneoplastic stromal proliferative process. The characteristic morphologic appearance, immunophenotype, and benign clinical course suggest that this is a distinctive nonneoplastic vascular lesion of the spleen that we propose to designate as sclerosing angiomatoid nodular transformation (SANT).
    Sclerosing angiomatoid nodular transformation of the spleen. Teng Xiaodong,Yu Xinru,Wang Guihua,Xu Linjie,Lai Maode Analytical and quantitative cytology and histology OBJECTIVE:To study clinical and pathologic features of sclerosing angiomatoid nodular transformation (SANT) and differential diagnosis, we reviewed splenectomy specimens from the Department of Pathology, First Affiliated Hospital, School of Medicine, Zhejiang University (January 1990 to December 2006) and another case from consultation at Second Jiaxing Municipal Hospital, Zhejiang Province, finding 7 cases of this lesion. STUDY DESIGN:Clinicopathologic characteristics and immunophenotype of 7 cases of SANT were studied. RESULTS:Five cases were incidentally found during routine examination. One had concurrent hepatic angioma. Microscopically, all cases were characterized by multiple angiomatoid nodules of various sizes embedded in fibrosclerotic stroma. Each nodule was composed of slit-like, round or irregularly shaped vascular spaces lined by plump endothelial cells and interspersed by a population of spindle or ovoid cells. In one case, an angiomatoid nodular lesion and a hamartoma-like lesion appeared together. Heterogeneous immunohistochemical features of the lining cells were revealed. CD34 was expressed in the narrow, well-formed capillaries and CD8 in some sinusoid-like structures, but without CD34 expression. CD31 staining highlighted numerous lining cells and interspersed cells. Some lining cells were focally CD68 positive. CONCLUSION:SANT is a rare lesion. Based on morphologic and immunohistochemical features, it may be a variant of splenic hamartoma.
    CT and MRI findings of sclerosing angiomatoid nodular transformation of the spleen: spoke wheel pattern. Karaosmanoglu Devrim A,Karcaaltincaba Musturay,Akata Deniz Korean journal of radiology 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. 10.3348/kjr.2008.9.s.s52
    Coexisting sclerosing angiomatoid nodular transformation of the spleen with multiple calcifying fibrous pseudotumors in a patient. Lee Jen-Chieh,Lien Huang-Chun,Hsiao Cheng-Hsiang Journal of the Formosan Medical Association = Taiwan yi zhi 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. 10.1016/S0929-6646(09)60245-X
    [Sclerosing angiomatoid nodular transformation of spleen]. Teng Xiao-Dong,Yu Xin-Ru,Wang Gui-Hua,Xu Lin-Jie,Lai Mao-de Zhonghua bing li xue za zhi = Chinese journal of pathology OBJECTIVE:To study the clinicopathologic features of sclerosing angiomatoid nodular transformation of spleen and its differential diagnosis. METHODS:The clinicopathologic characteristics and immunophenotype of 4 cases of sclerosing angiomatoid nodular transformation of spleen were studied. RESULTS:Histologically, all cases were characterized by multiple angiomatoid nodules of various sizes in a fibrosclerotic stroma. The nodules were round and sometimes convoluted. They were composed of slit-like, irregular-shaped or slightly dilated vascular spaces lined by plump endothelial cells and interspersed with a population of spindly or ovoid cells. Immunohistochemical study showed a heterogeneous staining pattern, with the lining cells of the small capillaries expressing CD34 and those of the sinusoid-like structures expressing CD8. CD31 highlighted both the lining cells and interspersed cells, resulting in a complex meshwork. The lining cells were also focally positive for CD68. Smooth muscle actin revealed conglomerates of spindly shaped cells around and between the vascular channels. These spindly shaped cells in the intervening stroma were focally positive for actin, but negative for desmin, CD21 and CD35. CONCLUSIONS:Sclerosing angiomatoid nodular transformation is a rarely encountered benign lesion of the spleen, which should be distinguished from other angiomatoid tumors and tumor-like lesions.
    Detection of Epstein-Barr virus-encoded small RNA-expressed myofibroblasts and IgG4-producing plasma cells in sclerosing angiomatoid nodular transformation of the spleen. Kashiwagi Satoko,Kumasaka Toshio,Bunsei Nobukawa,Fukumura Yuki,Yamasaki Shigetaka,Abe Keiko,Mitani Keiko,Abe Hiroshi,Matsumoto Toshiharu,Suda Koichi Virchows Archiv : an international journal of pathology Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare inflammatory tumor-like lesion composed of vascular nodules and non-neoplastic stroma including spindle cells and inflammatory cells. The focus of our study was on the stromal proliferating process in SANT. Nine cases of SANT were examined. All cases showed alpha-smooth muscle actin (alpha-SMA) and vimentin on the spindle cells but not CD21, CD31, CD34, CD68, desmin, S100, human herpes virus-8, or anaplastic lymphoma kinase-1. In one case, 20-30% of the myofibroblasts in Epstein-Barr-virus (EBV)-positive spindle cells were detected using double-labeling immunohistochemistry for alpha-SMA and EBV-encoded small RNA in situ hybridization. A quantitative analysis of IgG and IgG4-positive plasma cells (pPCs) in SANT was performed. The median densities of IgG-pPCs and IgG4-pPCs in SANT were approximately four-fold and 13-fold higher than those in the normal spleens, respectively. In addition, there was a statistically significant increase of IgG4/IgG-pPCs ratio in SANT in comparison to the control specimens. In conclusion, the fibrogenesis in a subset of SANT may be associated with EBV-infected myofibroblasts in an overlapping immune reaction indicated by the presence of infiltrating IgG4-pPCs. Further investigation is needed to elucidate the association between SANT and IgG4-related sclerosing disease. 10.1007/s00428-008-0648-z
    Splenic angiomatoid nodular transformation in child with inflammatory pseudotumor-like areas. Vyas Monika,Deshmukh Mahesh,Shet Tanuja,Jambhekar Nirmala Indian journal of pathology & microbiology Reports of sclerosing angiomatoid transformation (SANT) in the pediatric age group are rare. We present a case of SANT in an 11-year-old child with a history of trauma presenting with rapidly growing splenic lesion since 2 months. A partial splenectomy revealed a well-demarcated nodular lesion 5 × 4 × 4 cm with central area of fibrosis. Most part of the lesion showed ill-defined nodules or diffuse areas of plump epithelioid appearing endothelial units that marked with CD31, but the internodular stroma was inflammatory pseudotumor (IPT)-like with a mitotic count of 1-2/10 hpf. The angiomatoid nodules were diffusely positive for CD31, CD163, and CD68; however, they were negative for CD34, CD30, smooth muscle actin, and CD8. Epstein-Barr virus-encoded RNA in situ hybridization (EBER-ISH) was negative. The MIB1 labeling was fairly high in the IPT area but low in the angiomatoid areas. After the diagnosis of SANT, the patient has had an uneventful follow-up for more than 3 years since surgery. The morphologic findings in the case being discussed reaffirm the finding that SANT may have an IPT component and it can be seen even in pediatric age group. 10.4103/0377-4929.91543
    Sclerosing angiomatoid nodular transformation (SANT) of the spleen: A case report on CT and MRI. Vigorito Raffaella,Scaramuzza Davide,Pellegrinelli Alessandro,Marchianò Alfonso BJR case reports Solid tumors of the spleen are rare, with an incidence of 0.007% in all operating and autopsy specimens. In terms of microscopic structure and function, the spleen consists of two parts: the white pulp, which plays an important role in the immune system and the red pulp, which filters the blood.Primary splenic neoplasms can be classified into lymphoid neoplasms arising from the white pulp, and vascular neoplasms which arise from the red pulp.Primary tumors arising from vascular elements include benign lesions such as hemangioma, lymphangioma and hamartoma, intermediate lesions such as hemangioendothelioma, hemangiopericytoma and littoral cell angioma as well as the frankly malignant hemangiosarcoma.It is usually difficult to distinguish a benign from a malignant lesion with preoperative imaging studies and cytological exam by fine-needle aspiration (FNA), that is not easily obtained because of the risk of bleeding.Therefore a splenectomy should be necessary for a definitive diagnosis of splenic tumors.Martel and all for the first time described the sclerosing angiomatoid nodular transformation (SANT), like a vascular lesion of the spleen, with benign clinical course consisting by altered red pulp tissue that has been entrapped by a non-neoplastic stromal proliferative process.We describe a rare case of benign splenic mass documented with FDG/PET-CT (referred as equivocal), CT and MRI. 10.1259/bjrcr.20180036