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

Sclerosing Angiomatoid Nodular Transformation of the Spleen in a Patient With Granulomatosis With Polyangiitis

We present an intriguing case involving a rare occurrence of sclerosing angiomatoid nodular transformation (SANT) in a 57-year-old woman with a history of granulomatosis with polyangiitis (GPA). Despite the extensive literature on SANT, its pathogenesis remains elusive. The patient, diagnosed with serum anti-proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA)-positive GPA seven years earlier, exhibited a splenic lesion during imaging, leading to laparoscopic splenectomy due to severe abdominal pain. Microscopic analysis unveiled nodular structures with vascular elements surrounded by fibrosclerotic stroma and chronic inflammatory cells. This case raises questions about the interplay between SANT, GPA activity, and vascular damage. Hypotheses regarding SANT's origin, including its potential association with organized hematoma or alterations in splenic blood flow, are discussed. The uniqueness of this case lies in the coexistence of PR3-ANCA-positive GPA and SANT, suggesting a potential link between GPA activity, vascular damage, and SANT development. While causality remains uncertain, this report marks the first documented case of a patient with PR3-ANCA-positive GPA developing SANT. The findings prompt reflection on a potential common pathophysiological mechanism and underscore the importance of considering SANT in cases of splenic lesions associated with conditions causing alterations in splenic blood flow. This contribution serves as a valuable addition to the existing knowledge, urging further research and consideration of SANT in diagnostic scenarios involving splenic abnormalities.

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

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

Sclerosing Angiomatoid Nodular Transformation of the Spleen: A Diagnostic Conundrum

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

Rapidly growing sclerosing angiomatoid nodular transformation of the spleen

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

Sclerosing angiomatoid nodular transformation (SANT) of the spleen: a rare cause of acute abdomen

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is an extremely rare benign lesion. It originates from the spleen's red pulp; however, its pathogenesis is not clearly defined. These tumors are usually asymptomatic or cause nonspecific abdominal symptoms. Most SANTs are found incidentally on radiographic examination or during surgery for an unrelated condition. The differential diagnosis from other splenic tumors or malignant lesions can be challenging due to the risk for a possible malignancy of the suspicious lesion. As more SANTs are being discovered and treated, they should always be considered in the differential.

We present the case of an otherwise healthy 30-year-old female; she presented with abdominal pain and a mass in her spleen. Surgery was performed, and an SANT was discovered. The patient underwent full recovery, and on follow-up is doing well.

Revisiting the Spleen—An Imaging Review of the Common and Uncommon Splenic Pathology

The spleen is the largest lymphatic organ and is responsible for both hematological and immunological functions. Several common etiologies such as trauma, developmental variants, infectious/inflammatory conditions, and benign and malignant lesions can occur in the spleen. The role of imaging modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) in diagnosing these conditions continues to evolve. The main objective of this review article is to illustrate the role of imaging in identifying the common and uncommon pathology of the spleen.

CT and MRI features of sclerosing angiomatoid nodular transformation of the spleen: A report of 18 patients with pathologic correlation

PURPOSE

The purpose of this study was to describe the computed tomography (CT) and magnetic resonance imaging (MRI) features of sclerosing angiomatoid nodular transformation (SANT) of the spleen and correlate imaging features with those obtained at histopathologic analysis.

MATERIALS AND METHODS

A total of 18 patients (9 men, 9 women; mean age, 42.2±10.7 [standard deviation (SD)] years; range, 23-59 years) with histopathologically confirmed SANT were retrospectively evaluated. The presenting symptoms, gross pathologic changes, and histopathologic and correlative immunohistochemical results were recorded. CT (n=8) and MRI (n=12) features were analyzed by two radiologists and included number, size, shape, boundary, attenuation, signal intensity, and enhancement patterns.

RESULTS

Seventeen patients (17/18; 94%) had a single SANT without specific clinical symptoms and one patient (1/18; 6%) had multiple SANTs with left-upper-quadrant bloating and pain. The largest lesion diameter exceeded 3cm. On plain CT images, SANTs were slightly hypoattenuating in seven patients (7/8; 88%), isoattenuating in one patient (1/8; 13%), and contained calcification in two patients (2/8; 25%). On T2-weighted MR images, SANTs displayed hypointensity in ten patients (10/12; 83.3%), isointensity in one patient (1/12; 8%) and hyperintensity in one patient (1/12; 8%). On T2-weighted images, stellate or scattered fibrous scars were observed in all patients (12/12; 100%). On diffusion-weighted images, SANTs appeared as heterogenous or homogeneous hypointense in 12 patients (12/12; 100%). Compared to out-of-phase images, SANTs displayed decreased local signal intensity on in-phase images in 12 patients (12/12; 100%). On enhanced CT and MRI images, SANTs had clear boundaries (17/18; 94%), oval (7/18; 39%) or lobular (7/18; 39%) shape, displayed progressive centripetal enhancement (18/18; 100%), spoke-wheel pattern (14/18; 78%), nodular enhancement (11/18; 61%), or delayed enhancement of central fibrous scar (9/18; 50%).

CONCLUSIONS

SANT of the spleen predominantly manifests as a solid, single, oval or lobular, and well-defined lesion with a fibrous scar and occasional calcification. Typical enhancement characteristics include progressive and centripetal enhancement, spoke-wheel pattern, nodular enhancement, and delayed enhancement of central fibrous scar. Hypointensity on T2- and diffusion-weighted images are due to hemosiderin deposition and fibrous tissue.

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.

Sclerosing angiomatoid nodular transformation of the spleen: unusual case presentation in an intravenous drug user

An unusual presentation of sclerosing angiomatoid nodular transformation in a 42-year-old man who was admitted with jaundice, deranged liver function tests and subsequently diagnosed with acute hepatitis C infection in the context of recent intravenous drug use. During his admission, he had an ultrasound of the abdomen followed by a CT thorax, abdomen and pelvis which showed splenomegaly and a large splenic lower pole mass that was hypoechoic and concerning for lymphoma. A bone marrow biopsy showed no evidence of lymphoma and an ultrasound-guided biopsy of the splenic mass suggested unusual features with vascular proliferation, either neoplastic or reactive, with no evidence of lymphoma or high-grade sarcoma. Given the concern for malignancy, an open splenectomy was required to determine the nature of the lesion with histologic findings consistent with a non-neoplastic benign vascular lesion favouring sclerosing angiomatoid nodular transformation.

Sclerosing angiomatoid nodular transformation of the spleen: case report of a metastatic carcinoma-simulating disorder

Sclerosing angiomatoid nodular transformation (SANT) is a rare nonneoplastic splenic disorder of unknown etiopathogenesis. This condition is usually found incidentally on imaging studies. Because of its similar features, SANT can wrongly be described as metastatic carcinoma. A 61-year-old Caucasian male was referred to our general surgery outpatient clinic regarding unusual splenic nodular formations in a routine abdominal ultrasound. All diagnostic exams performed confirmed metastatic splenic lesions, but no primary tumor was found. A laparoscopic splenectomy was performed for diagnostic purposes. Histopathology revealed SANT. Benign tumors of the spleen are uncommon entities and can easily be mistaken by malignant secondary lesions. The differential diagnosis of SANT should include other vascular lesions as well as metastatic carcinoma and inflammatory pseudotumor. It is widely recommended that a splenectomy should be performed because only by histopathology and immunohistochemistry staining, the definitive diagnosis of SANT can be made.

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 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.

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

Introduction

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

Presentation of Case

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

Discussion

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

Conclusion

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

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

Introduction

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

Case Description

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

Conclusions

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

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

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

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