Sclerosing angiomatoid nodular transformation of the spleen

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

INTRODUCTION AND IMPORTANCE

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

CASE PRESENTATION

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

CLINICAL DISCUSSION

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

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

SANT is a rare, non-lymphoid, benign entity, originating from the red pulp of the spleen. It is characterized by the presence of vascular nodules surrounded by a stroma of collagen fibers. It was introduced as a distinct disease entity by Martel et al in 2004, after the histopathological examination of 25 cases. Symptoms are unspecific, and in most cases, it is incidentally diagnosed, mostly in patients who undergo imaging for other underlying conditions. Moreover, radiological findings are usually inconclusive, and a definite diagnosis is established through histopathological examination. We herein report the case of a 76-year-old female diagnosed with stage I rectal cancer who was subsequently diagnosed with a splenic lesion after a Computed Tomography (CT) scan that was performed for follow-up purposes. Different imaging modalities were employed for further assessment; however, findings were inconclusive and the possibility of metastatic disease could not be excluded. The patient was referred for splenectomy and the diagnosis of SANT was established through histopathological examination.

Sclerosing angiomatoid nodular transformation of spleen: A rare case report

ABSTRACT

Sclerosing angiomatoid nodular transformation (SANT) is a reactive non-neoplastic, rare vascular lesion of the spleen. The histology shows multiple angiomatoid nodules surrounded by proliferative stroma. A 31-year-old lady presented with an abdominal mass for 6 months. Contrast-enhanced computed tomography (CECT) abdomen was suggestive of hemangiopericytoma/hemangioendothelioma. An open splenectomy was performed, and the resected specimen was sent for histopathology examination. The gross examination showed a bosselated mass present at the lower pole of the spleen measuring 8 × 8 cm with peripherally located coalescing red-brown nodules embedded in a dense fibrous stroma on the cut surface. On microscopy, multiple circumscribed angiomatoid nodules comprising irregular slit-like vascular channels lined by plump endothelial cells were seen embedded in dense sclerotic stroma. Because of the lack of specific diagnostic features, it is difficult to diagnose SANT clinically and radiologically. However, the typical histopathological findings are a clue in clinching the diagnosis.

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 (SANT) of the spleen: review of the literature

We present a sclerosing angiomatoid nodular transformation (SANT) case report in a 60 year-old-woman. SANT is an extremely rare benign disease of the spleen that it is radiologically similar to malignant tumors, and clinically difficult to differentiate from other splenic diseases. Splenectomy is both diagnostic and therapeutic in symptomatic cases. The analysis of the resected spleen is necessary to achieve the final diagnosis of SANT.

The Spectrum of Solitary Benign Splenic Lesions-Imaging Clues for a Noninvasive Diagnosis

Cross-sectional imaging of the upper abdomen, especially if intravenous contrast has been administered, will most likely reveal any acute or chronic disease harbored in the spleen. Unless imaging is performed with the specific purpose of evaluating the spleen or characterizing a known splenic lesion, incidentally discovered splenic lesions pose a small challenge. Solitary benign splenic lesions include cysts, hemangiomas, sclerosing angiomatous nodular transformation (SANT), hamartomas, and abscesses, among others. Sarcoidosis and tuberculosis, although predominantly diffuse micronodular disease processes, may also present as a solitary splenic mass lesion. In addition, infarction and rupture, both traumatic and spontaneous, may take place in the spleen. This review aims to describe the imaging features of the most common benign focal splenic lesions, with emphasis on the imaging findings as these are encountered on routine cross-sectional imaging from a multicenter pool of cases that, coupled with clinical information, can allow a definite diagnosis.

Controversies in the Spleen: Histiocytic, Dendritic, and Stromal Cell Lesions

Histiocytic, dendritic, and stromal cell lesions that occur in the spleen are challenging diagnostically, not well studied due to their rarity, and therefore somewhat controversial. New techniques for obtaining tissue samples also create challenges as splenectomy is no longer common and needle biopsy does not afford the same opportunity for examination of tissue. Characteristic primary splenic histiocytic, dendritic, and stromal cell lesions are presented in this paper with new molecular genetic findings in some entities that help differentiate these lesions from those occurring in non-splenic sites, such as soft tissue, and identify possible molecular markers for diagnosis.

Clinicopathological features of sclerosing angiomatoid nodular transformation of the spleen

PURPOSE

To explore the clinicopathological features of sclerosing angiomatoid nodular transformation (SANT) of the spleen.

METHODS

The clinicopathological data of 26 SANT patients were analyzed.

RESULT

There were 15 men and 11 women, aged 23-62 years (mean: 43.9 years; median: 43 years). Twenty patients were found during health check-ups. Magnetic resonance imaging had significantly higher specificity than other imaging modes in the diagnosis of SANT. Macroscopically, the lesions were gray-red and gray-white, along with well-demarcated nodules. Microscopy showed multiple angiomatoid nodules embedded in hyperplastic fibrous tissues and dense collagen fiber; the angiomatoid structures inside the nodules had varied morphology. Patchy and nodular fresh and old hemorrhages were observed in each lesion. Proliferative fibroblasts were seen in the stroma, along with infiltration of a few mixed inflammatory cells. Serum tumor markers were negative. Fourteen patients (53.8 %) had benign or malignant lesions in other parts of the body, including the liver, kidneys, and adrenal and pituitary glands which were similar to von Hippel-Lindau (VHL) syndrome. The reasons for occurrence of SANT may be as follows: hemangioma/lymphangioma or splenic congestion with extensive hemorrhage and secondary changes.

CONCLUSIONS

SANT is a rare benign vascular lesion with some clinical manifestations similar to VHL syndrome. Patients have good prognosis after tumor removal.

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: Analysis of Clinical and Pathological Features in Five Cases

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

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

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

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

Calcifying fibrous tumor of the gastrointestinal tract: A clinicopathologic review and update

Calcifying fibrous tumor (CFT) is a rare mesenchymal lesion that has been documented throughout the gastrointestinal tract. Gastrointestinal CFTs may occur at virtually any age, with a predilection for adults and for females. They occur most commonly in the stomach and the small and large intestines. CFTs are most often found incidentally, cured by local resection, and have a low risk of recurrence. Histology shows three characteristic features: Spindle cell proliferations within a densely hyalinized stroma, scattered calcifications, and lymphoplasmacytic inflammation. CFTs are immunoreactive for CD34, vimentin and factor XIIIa, helping to distinguish them from other benign mesenchymal neoplasms. The differential diagnosis of CFTs includes sclerosing gastrointestinal stromal tumor, leiomyoma, schwannoma, solitary fibrous tumor, inflammatory myofibroblastic tumor, plexiform fibromyxoma, fibromatosis, sclerosing mesenteritis, and reactive nodular fibrous pseudotumor. The pathogenesis of CFTs remains unclear, but some have hypothesized that they may be linked to IgG4-related disease, inflammatory myofibroblastic lesions, hyaline vascular type Castleman disease, sclerosing angiomatoid nodular transformation of the spleen, or trauma.

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

The authors described a case of sclerosing angiomatoid nodular transformation of the spleen (SANT) in a 50-year-old woman presented with persistent neutrophilia and unintentional weight loss. An incidental splenic mass was initially found on abdominal ultrasound. It was found to be progressive in size and with high likelihood of central necrosis on further CT of abdomen and pelvis. The patient subsequently underwent an uneventful laparoscopic splenectomy. The splenic specimens were sent for laboratory analysis and the histopathological findings were highly suggestive of SANT. The patient then had routine surgical follow-ups and was eventually discharged with no further clinical concern.

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 (SANT) in a patient with clear cell carcinoma of the uterus: a case report

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.

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: A case report and literature review

Sclerosing angiomatoid nodular transformation (SANT) is a rare benign splenic vascular lesion. Since it was first defined in 2004, a total of 132 cases of SANT have been reported in ~50 studies in the English literature. However, it remains difficult to form a definitive pre-operative differential diagnosis of SANT compared with other splenic tumors or malignant lesions. The present study reports a pathologically proven case of SANT in a 29-year-old man who initially presented with left upper quadrant and back discomfort. The study also provides a review of the current knowledge on the condition, including the clinical profile, imaging features, cytological features, differential diagnosis and treatment of SANT. The most important distinguishing features of SANT are its typical vascular character and lack of other features that are typical of a granuloma. A splenectomy is required and the diagnosis is based on pathological analysis.

Up-regulated expression of PTEN after splenetomy may prevent the progression of liver fibrosis in rats

BACKGROUND/PURPOSE

To investigate the mechanisms of delaying progression of liver fibrosis by splenectomy.

METHODS

Liver fibrosis was induced by common bile duct ligation. Rats were divided into 3 groups randomly: group A with common bile duct ligation and splenectomy (n = 45), group B with common bile duct ligation and spleen sham operation (n = 45), group C with sham common bile duct ligation and spleen sham operation (n = 45). Liver samples were collected at the 1st, 3rd and 5th week. H&E staining and Sirius staining were used to evaluate the degree of liver fibrosis, immunohistochemical staining was used to measure the expression of α-SMA and PTEN. PTEN mRNA and protein expression was measured by real-time PCR and Western-blot.

RESULTS

Over time, liver fibrosis developed gradually in group A and B. The expression of PTEN mRNA and protein in group A was higher than that in group B (P < 0.05), while the expression of α-SMA was higher in group B (P < 0.05). The expression of PTEN was negatively correlated with α-SMA (r = -0.86, P < 0.05).

CONCLUSIONS

In this study, splenectomy can up-regulate the expression of PTEN and reduce the secretion of α-SMA, thereby deterring the progression of liver fibrosis.