Sclerosing angiomatoid nodular transformation of the spleen masquerading as a sarcoma metastasis

Abstract

We report a case of sclerosing angiomatoid nodular transformation (SANT) of the spleen presenting as an incidental splenic mass in a patient with a history of retroperitoneal spindle cell sarcoma. Imaging studies and preoperative fine needle biopsy failed to differentiate this lesion from other vascular splenic lesions or a metastatic focus of a prior sarcoma. The patient was treated with splenectomy, which has proved both diagnostic and therapeutic in this and other cases of SANT. Although histology can lead to the diagnosis of vascular tumor, immunohistochemistry is the only way to confirm the diagnosis of SANT. The etiology of SANT is unknown. SANT of the spleen is a benign lesion that does not recur after splenectomy.

Rare tumor of the spleen - case report

“…Most patients are asymptomatic as published on a series by Diebold et al Nevertheless, some patients presented abdominal pain and discomfort or splenomegaly. [5] When symptomatic, the most common symptom is abdominal pain. Cytopenias, pelvic pain, flank pain, palpable left upper quadrant mass, and long standing fever are alternative presentations.…”

“…A: CD8 immunostain highlights sinusoid-like spaces; B: CD34 immunostain highlights the capillaries; C and D show immunoreactivity for CD31 SANT presents itself on CT scans and magnetic resonance imaging has a hypodense mass. The differential diagnosis includes neoplasms like lymphoma, metastatic lesions and benign lesions such as hamartoma, [5] which emphasizes the importance of the diagnostic confirmation. Spleen biopsy can be performed and makes the diagnosis.…”

“…Individual nodules are composed of slit-like, globular or irregularshaped vascular spaces interspersed by a population of thin or ovoid cells and lined up by pudgy endothelial cells conferring them an angiomatoid appearance. [5] Usually they have clear margins with normal parenchyma. SANT is reliably distinguished from other tumors by immunohistochemical staining.…”

“…Angiomatoid nodules display three distinct types of vessels: CD34 -/CD8 -/CD31 + small veins, CD34 -/CD8 + /CD31 + sinu-soids and CD34 + /CD8 -/CD31 + capillaries. [5] Other splenic vascular lesions don't meet these criteria. In this case, the authors decided to perform an ultrasound-guided spleen biopsy as it meant a shorter length of stay in the hospital and an earlier return to normal activity.…”

“…[3,4] Other than hematopoietic neoplasms like lymphoma, the most common primary nonhematopoietic tumors of the spleen contemplate hemangioma, littoral cell angioma, lymphangioma, hemangioendothelioma, hamartoma and SANT. [5] The histological appearance and the immunohistochemical staining makes the diagnosis. [6]…”