Among isolated primary splenic disorders, approximately 50 cases of benign vascular lesion referred to as sclerosing angiomatoid nodular transformation
(SANT) have been described. Formerly reported under different names as cord capillary haemangioma, splenic hamartoma, multinodular haemangioma
or as a variant of splenic haemangioendothelioma, the lesion was finally designated in 2004 by Martel et al
The most common presentations were incidental finding of an asymptomatic splenic mass, abdominal pain or discomfort, and splenomegaly. To the best of our knowledge, a clear association with other symptoms or complaints has not been described so far. In the original report of Martel describing the largest series so far, one out of 25 patients presented with leukocytosis, polyclonal gammopathy, and raised erythrocyte sedimentation rate (ESR), one with fever, one with mild anaemia, and another one with pancytopenia with elevated ESR. More clinical data are given in the Diebold study [6
]. Three out of 16 patients in his study had some inflammatory condition and other 3 had anaemia.
The unique feature of our case was a generalized inflammatory reaction manifested by fever, muscular and joint pain, elevation of ESR, CRP and fibrinogen, and iron-deficiency anaemia. This clinical picture necessitated a diagnostic workup in the search for a possible explanation, and as a final result the tumour of the spleen was found. This history is somewhat distinct from previous reports. The radiographic, gross, histological, and immunophenotypical features were similar to the cases previously described in the literature.
The main differential diagnoses of SANT include littoral cell angioma, splenic haemangioendothelioma, inflammatory myofibroblastic tumour, splenic hamartomas and nodular transformation of splenic red pulp in response to metastatic carcinoma [7
]. Others are congestive splenomegaly, infarction and Kaposi's sarcoma [14
The clinical features present in our case support the assumption that there might be some inflammatory component in the aetiology of this disease. According to different authors, some lesions may represent some form of inflammatory pseudotumours, hamartomatous lesions, red pulp transformation in response to exaggerated stromal proliferation or organized haematomas [15
]. The theory about inflammatory components in the aetiology could be supported by complete disappearance of the biochemical indicators of inflammation after surgical removal of the tumour.
In practice, highly vascularised lesions in the splenic parenchyma are very difficult to differentiate preoperatively [18
]. The most common pathological finding is haemangioma, but other tumours such as splenic hamartoma, haemangioendothelioma, littoral cell angioma, benign vascular tumours with myoid and angioendotheliomatous features, inflammatory myofibroblastic tumour (inflammatory pseudotumour) or hamartomas are occasionally found [6
]. Usually the only method to establish an unequivocal diagnosis is pathological examination of the spleen, and splenectomy is considered both diagnostic and curative. The main reason for surgical management is uncertainty about the nature of the tumour of the spleen. This approach is particularly supported by the fact that many patients with SANT have a history of previous malignancy, and splenic tumour is frequently found during routine follow-up in the search for metastases. Moreover, clinical and radiological features of the SANT may mimic nodular transformation of the splenic red pulp in response to metastatic carcinoma, and important risk of this pathology is the strongest indication for splenectomy.
In all reports, splenectomy is considered curative with regard to the risk of recurrence. However, this treatment is associated with all the long-term risks related to asplenia. Most important seems the overwhelming post-splenectomy infection (OPSI) with the high mortality rate related to this disease entity. Benign nature of the tumour in various imaging techniques including CT, MRI or positron emission tomography (PET) scans allows for a different surgical approach. Whenever technically possible, partial splenectomy with adequate margins of uninvolved tissue seems appropriate. With high experience in advanced minimally invasive procedures the laparoscopic approach is considered beneficial [22
Owing to the extensive experience in laparoscopic operation of the spleen, we may conclude that even though indications for spleen preserving procedures are scarce, they are highly beneficial for the patient. If the vascular anatomy and localization of the lesion allow for the selective devascularization of the affected part of the spleen, the SANT tumour could be considered for laparoscopic hemisplenectomy. Generally, the best indications for this advanced procedure are splenic cysts and tumours with benign radiological phenotype localized in the upper or lower part of the spleen. Central localization of the lesion usually does not allow for partial splenectomy.
Relatively high prevalence of malignancy among patients with SANT was described. However, further studies are needed to conclude whether it could be classified as paraneoplastic syndrome or it is just the result of frequent use of the variety of imaging studies in oncological patients that lead to the detection of various asymptomatic lesions. So far – as long as the data about the relationship between SANT and malignancy is not clear – regular follow-up should be recommended in all patients with confirmed SANT.