Diagnosis & Discussion
Diagnosis
Sclerosing Angiomatoid Nodular Transformation of the Spleen (SANT).
Discussion
Sclerosing angiomatoid nodular transformation of the spleen (SANT) is a rare benign splenic red pulp lesion with substantial fibrosclerotic stroma. This entity was previously called splenic hamartoma, cord capillary hemangioma, and multinodular hemangioma by other authors. These lesions are common in young adults and are usually an incidental finding during radiographic imaging.
SANT commonly appears as multiple angiomatoid nodules in varying shapes and sizes surrounded by fibrosclerotic or myxoid stroma. The nodules can sometimes be surrounded by normal splenic parenchyma or concentric layers of collagen. The center of the nodules has slit-like or sinus-like vascular spaces which are lined by plump endothelial cells and contain red blood cells within the vessels or may have red blood cell extravasation. Immunohistochemical staining shows three types of vessels within the nodules essentially recapitulating the normal splenic red pulp: capillaries (CD31+, CD8-, CD34+), sinusoids (CD31+, CD8+, and CD34-), and small veins (CD31+, CD8-, CD34-). Splenectomy is both diagnostic and therapeutic in symptomatic patients.
References
1. Martel M, Cheuk W, Lombardi L, Lifschitz-Mercer B, Chan JKC, Rosai J. Sclerosing Angiomatoid Nodular Transformation (SANT): Report of 25 Cases of a Distinctive Benign Splenic Lesion. The American Journal of Surgical Pathology. 2004;28(10):1268-79.
2. Rodriguez F. Rosai and Ackerman’s Surgical Pathology, 9th ed. The American Journal of Surgical Pathology. 2004;28(10):1399-400.
3. Shankar V. Sclerosing angiomatoid nodular transformation. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/spleensclerosingangiomatoid.html. Accessed February 26th, 2021.
4. Roberto N. Miranda, L. Jeffrey Medeiros. Sclerosing angiomatoid nodular transformation. https://app.expertpath.com/document/sclerosing-angiomatoid-nodular-tra-/202ca900-ec11-4427-ae76-442c3e30c7be. Accessed February 26th, 2021.
5. Mills, S. E.; Carter, D.; Greenson, J. K.; Reuter, V. E.; Stoler, M. H. (Eds.) Sternberg's Diagnostic Surgical Pathology. 5th ed (2010)