Sclerosing Angiomatoid Nodular Transformation (SANT) in Spleen - A Case Report -

Sclerosing angiomatoid nodular transformation of the spleen presenting rapid growth after adrenalectomy: Report of a case

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SANT displayed a rapid growth in size from 20 mm to 70 mm during 3 years after adrenalectomy.

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Splenectomy was performed by hand assisted laparoscopic surgery (HALS).

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Corticosteroids might be useful for treating SANT.

Introduction

Sclerosing angiomatoid nodular transformation (SANT) is a rare benign lesion with an unknown natural history and pathogenesis. So far fewer than 100 cases were documented, but detailed incidence and prevalence are unknown.

Presentation of case

We report a case of SANT of the spleen in a 37-year-old man that showed rapid growth after adrenalectomy for primary aldosteronism. Computed tomography showed a nodule in the spleen that increased in size from 2.0 cm to 7.0 cm during 3 years of observation.

Discussion

This case is reported because data regarding growth rates and natural history of these lesions are limited and few cases have been reported to show the rapid growth progression seen in this case.

Conclusion

Decreases in glucocorticoid concentrations following adrenalectomy may have contributed to the rapid growth of SANT of the spleen, because SANT is considered to be related to immunoglobulin G4-associated disease.

Differentiation of an unclear splenic lesion in a patient with cholangiocarcinoma

Here we report on a 51-year-old man with the primary diagnosis of cholangiocarcinoma. Workup with CT and contrast-enhanced ultrasound revealed an additional lesion in the spleen, raising the concern for metastasis. Combined FDG PET/CT revealed a different metabolic pattern, making a metastasis unlikely. Histopathology of the splenic lesion confirmed sclerosing angiomatoid nodular transformation, a rare benign lesion of the spleen.

Sclerosing angiomatoid nodular transformation of the spleen: CT and MRI features with pathologic correlation

OBJECTIVE

The objective of this study was to describe the CT and MRI features of sclerosing angiomatoid nodular transformation of the spleen with pathologic correlation.

MATERIALS AND METHODS

Nine patients with surgically resected and pathologically confirmed sclerosing angiomatoid nodular transformation were included in the study. Clinical history was reviewed to determine patient demographics and symptoms at presentation. Gross pathologic, histologic, and immunohistochemical findings were recorded. CT (n = 9) and MRI (n = 4) examinations were evaluated for lesion shape and margins, intrinsic characteristics, and enhancement pattern.

RESULTS

Patients included were six women and three men, with a mean age of 41.2 years. Pathologic features of sclerosing angiomatoid nodular transformation included multiple angiomatous nodules in a radiating pattern with a central stellate fibrous scar and evidence of hemosiderin deposition. On imaging, the lesions were solitary and round, 78% having a lobulated margin. They were heterogeneously hypoenhancing during the arterial and portal venous phases of contrast-enhanced CT or MRI, with peripheral enhancing radiating lines in 88% of lesions. They showed progressive enhancement and were isoenhancing or hyperenhancing in the delayed phase. A hypoenhancing central scar was shown on imaging in 22% of lesions. All lesions were hypointense on T2-weighted images.

CONCLUSION

Sclerosing angiomatoid nodular transformation shows characteristic CT and MRI findings reflecting the underlying pathology. Typical features are a solitary, round, lobulated mass with early peripheral enhancing radiating lines and progressive enhancement of the angiomatous nodules; delayed enhancement of the fibrous tissue; and hypo-intense T2 signal intensity from hemosiderin deposition.