Histopathological and Immunohistochemical Diagnosis of Spleen Lymphoma with Atypical Clinic Presentation: Case Report

Abstract

Introduction: Both the splenic angiosarcoma and the B-cell non-Hodgkin’s lymphoma (NHL) are not only rare but are challenging to diagnose. Case report: Male patient, 45 years old, obese, night sweats for one year, and cyclic abdominal pain for two years, with an initial angiosarcoma clinic, however after immunohistochemistry test, it was revealed a B-cell NHL with atypical presentation. The total abdomen ultrasound (US) performed at the onset of the night sweating symptom showed no alterations. After one year, the US showed a splenic mass. Magnetic resonance imaging of the abdominal region revealed a heterogeneous expansive splenic lesion in the anterior aspect with suspected splenic angiosarcoma. After full splenectomy, caudal pancreatectomy, and retroperitoneal lymphadenectomy, histological analysis showed an area of poorly differentiated necrotic malignancy infiltrated in the splenic parenchyma. Immunohistochemical analysis was positive for CD20 reagents in several foci, BCL2, and for KI67 (in ninety percent of the neoplastic cell nucleus). Histopathology and immunohistochemistry are consistent with high-grade, diffuse, NHL of immunophenotype B in the spleen, with no sign of metastasis to adjacent tissues. After total splenectomy and four rounds of chemotherapy, the patient had remission of the tumor and was asymptomatic. Conclusion: It is extremely important to recognize the relevance of the correct diagnosis of rare neoplasms such as the one reported. Both clinical and imaging tests, although important, can be inaccurate, reiterating the importance of complementary histologic and immunohistochemical tests.