Sclerosing angiomatoid nodular transformation of spleen with calcifying fibrous pseudotumor: A rare case with unusual association

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare benign vascular lesion of the spleen that was first described in 2004. SANT is associated with other concurrent diseases, mostly malignancies. Calcifying fibrous pseudotumor (CFPT) is a tumor-like lesion usually arising from soft tissue or peritoneal sub-serosa. Both SANT and CFPT are considered to be variants of the inflammatory myofibroblastic tumor. We report the rare case of a 24-year-old female presenting with a left abdominal mass that was clinically diagnosed as an extraintestinal gastrointestinal stromal tumor (GIST). Histopathological examination revealed SANT of spleen and CFPT. We report this case due to its rarity of occurrence and unusual association of SANT with CFPT.

MRI features and pathologic manifestations of splenic sclerosing angiomatoid nodular transformation / 中华普通外科杂志

Objective To investigate and summarize the MRI characteristics of splenic sclerosing angiomatoid nodular transformation (SANT).Methods A retrospective analysis of 5 SANT cases were analyzed,in terms of their MRI characteristics and pathological findings.Results MRI findings of SANT included:T1WI presents iso-signal or slightly low signal,all displayed lesions were detected as low signal compared with spleen,but higher than muscle signal on T2 WI,and with speck dots or starlike low signal in the central area,without necrosis and cystic change.The signal was significantly differentiated compared with the spleen on DWI.On chemical shift imaging,2 cases were showed slightly higher signal on out phase,the others without signal change.On enhanced scan,4 cases had edge obvious enhancement on arterial phase,inward filling enhancement,and the signal was higher than the spleen,1 case without arterial phase enhancement,but with mild concentric delayed enhancement.All of the speck dots and starlike areas decreased with time delay,with certain degree enhancement on delayed phase.Conclusions There were some MRI features of SANT,preoperative MRI can prompt diagnosis,but final diagnosis depends on pathology.

Sclerosing angiomatoid nodular transformation of spleen masquerading as a splenic abscess.

Here we report an incidental case of sclerosing angiomatoid nodular transformation (SANT) in an open splenectomy specimen from a young man who presented with insidious abdominal pain. The condition was mimicking as a splenic abscess. Histopathological and immunohistochemical analysis confi rmed this to be SANT. SANT presents a diagnostic challenge to clinicians, radiologists, as well as pathologists because of its extreme rarity. Therefore, it must be included as a differential diagnosis in cases with nonspecifi c pain or radiological splenic mass. This case highlights that SANT can present with varied clinical features and at a wide range of ages. A high index of suspicion is required for its diagnosis.

Multimodality imaging of splenic sclerosing angiomatoid nodular transformation

Sclerosing angiomatoid nodular transformation (SANT) is an exceedingly rare, benign and proliferative vascular lesion that arises from the splenic red pulp. It is often an incidental finding on imaging. The diagnosis of SANT is confirmed via histopathological examination of the resected spleen. Herein, we present a case of SANT and describe its typical imaging characteristics. An asymptomatic 39-year-old man was found to have a 3.1 cm × 2.7 cm × 2.3 cm hypoechoic splenic lesion during abdominal ultrasonography, which was performed to investigate his elevated gamma-glutamyl transpeptidase and alanine transaminase levels. Contrast-enhanced computed tomography suggested a vascular splenic lesion, while magnetic resonance imaging demonstrated features consistent with SANT. In view of the increasing size of the lesion on follow-up imaging, the patient elected for splenectomy. Histopathological examination confirmed SANT, and the lesion was completely resected by laparoscopic splenectomy.

Splenic angiomatoid nodular transformation in child with inflammatory pseudotumor-like areas.

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.

Laparoscopic splenectomy for sclerosing angiomatoid nodular transformation of the spleen / 대한외과학회지

Primary splenic tumors are rare and mainly found incidentally on radiologic studies. Among them, sclerosing angiomatoid nodular transformation (SANT) of the spleen is a new entity defined as a benign pathologic lesion. Most SANTs have no clinical symptoms and are occasionally accompanied by other splenic diseases such as malignancies. So, the exact diagnosis of the nature of the splenic tumor is mandatory for further treatment. But, preoperative diagnosis is not easy since it is difficult to obtain the tissue from the spleen for pathological study. Recently, laparoscopic splenectomy has become the more standard procedure for the spleen for diagnosis and treatment. Here, we report a rare case of SANT diagnosed following laparoscopic splenectomy.

Analysis of 4 cases of sclerosing angiomatoid nodular transformation of spleen / 上海第二医科大学学报

Objective To investigate the clinicopathologic features,diagnosis,differential diagnosis and treatment of sclerosing angiomatoid nodular transformation(SANT). Methods The clinical data,pathologic characteristics,immunophenotype and postoperative follow-up of SANT were analysed. Results There were no specific findings in the clinical manifestations of the 4 cases of SANT.Grossly,the cut surface of the masses was gray-white and vague nodularity was observed.Microscopically,it was characterized by the multinodular angiomatoid appearance in a fibrosclerotic stroma.The nodules were composed of slit-like,sinusoid-like vascular spaces and were interspersed with a population of spindly or ovoid cells.It was revealed by immunohistochemistry that the expression of CD34 in some vessels' endothelial cells was positive,and CD8 was negative.While in another vessels' endothelial cells,CD8 was positive and CD34 was negative.The expression of SMA,Actin,Vimentin,Collage IV and CD68 was positive in all of the 4 cases,while that of CD21,Desmin and NSE was negative.No relapse or metastasis was found during the follow-up.Conclusion SANT is a rarely encountered benign lesion of the spleen,which should be distinguished from the malignant tumor of the spleen.The diagnosis counts on the pathologic and immunohistochemical findings.It could be cured by splenectomy with a favourable prognosis.