Sclerosing angiomatoid nodular transformation in the spleen

Abstract

To assess the clinicopathologic features, differential diagnosis, and pathogenesis of sclerosing angiomatoid nodular transformation (SANT) of the spleen.The clinical characteristics of 7 cases with SANT were retrospectively analyzed. Histochemical and immunohistochemical (EnVision method) examinations were performed. Moreover, quantitative assessment of IgG4 and IgG-positive cells was performed.The 7 SANT patients included 1 female and 6 males, with ages ranging from 7 to 60 years (mean 33.4 years). They showed no specific clinical manifestations. Macroscopically, the surface of the excised masses was gray-white, and vague nodularity was observed. Mass sizes ranged from 3.0 to 7.0 cm (mean 5.5 cm). Microscopically, all cases were characterized based on multiple angiomatoid nodules of various sizes embedded in a fibrosclerotic stroma. The nodules were round and sometimes convoluted. Moreover, the nodules were composed of slit-like, irregularly-shaped, or slightly dilated vascular spaces lined by plump endothelial cells, and interspersed with a population of spindly or ovoid cells. Immunohistochemical examination showed a heterogeneous staining pattern, with the lining cells of small capillaries expressing CD34 and those of sinusoid-like structures expressing CD8. CD31 was stained in the lining and interspersed cells, thus resulting in a complex meshwork. Additionally, the lining cells were focally positive for CD68. Vimentin and smooth muscle antibody were expressed in all 7 cases, whereas no desmin or CD21 was detected. IgG4-positive cells accounted for 2 to 5 per high-power field (mean 3.7). Furthermore, the IgG-positive cells accounted for 2 to 8 per high-power field (mean 4.2).SANT is a rare primary benign tumor-like lesion of the spleen, and has characteristic histopathological features and immunohistochemical profiles. SANT should be distinguished from other angiomatoid tumors and tumor-like lesions. Moreover, SANT could be treated by splenectomy, with favorable prognosis. The relationship between SANT and IgG4-related sclerosing lesions remains to be clarified.

Sclerosing angiomatoid nodular transformation (SANT) of the spleen: a rare cause of acute abdomen

“…Tumors of the spleen are rare [ 1 ]. Their classification is varied, but they are usually classified into two main categories: nonlymphoid and lymphoid [ 1 , 2 ]. The most common primary malignancies of the spleen are lymphoma and angiosarcoma [ 1 ].…”

“…The most common primary malignancies of the spleen are lymphoma and angiosarcoma [ 1 ]. Metastasis to the spleen is extremely rare (2.3–7.1%) and usually found during autopsies from cutaneous malignant melanoma and breast cancer [ 1 , 2 ]. The majority of nonlymphoid primary tumors of the spleen are of vascular nature and are usually cavernous hemangiomas [ 2 , 3 ].…”

“…described a rare primary benign tumor-like lesion of the spleen with its own pathological features and immunohistochemical profile [ 1 , 2 ]. The name SANT of the spleen appeared [ 2 ]. Although it was first reported in 1978 by Silverman and LiVolski and defined as a special kind of hamartoma, Martel et al.…”

“…Sclerosing angiomatoid nodular transformation (SANT) is a rare benign disease of the spleen [ 1 , 2 ]. Clinical symptoms are nonspecific, and a suspicious splenic lesion is often suspected, leading to splenectomy [ 2 , 3 ]. Diagnosis is usually made histologically after complete resection.…”

Sclerosing angiomatoid nodular transformation presenting with thrombocytopenia after laparoscopic splenectomy - Case report and systematic review of 230 patients

“…The curative treatment for SANT is splenectomy [ 46 , [48] , [49] , [50] , [51] , [52] , [53] , [55] , [56] , [57] , [58] , [59] , [60] ]. Open splenectomy or minimally invasive splenectomy are both options for surgical treatment [ [62] , [63] , [64] , [65] , [66] , [67] , [68] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [77] ]. In recent years, minimally invasive surgery such as robotic or laparoscopic splenectomy has become more popular due to a shorter hospital stay, less postoperative abdominal pain, and an early return to normal activity [ 18 , [63] , [64] , [65] , 78 ].…”