Littoral cell angioma associated with extramedullary hematopoiesis and renal cell carcinoma: case report and review

Littoral cell angioma (LCA) is a rare primary vascular neoplasm of the spleen that originates from the endothelial littoral cell lining of the red pulp sinuses. LCA has mostly benign behavior with a few reported cases of malignancy. LCA is associated with comorbid visceral organ cancers and immunosuppressive states. We report a case of LCA with synchronous renal cell carcinoma and features of extramedullary hematopoiesis. Histologically, multiple splenic lesions were found with anastomosing vascular channels lined by plump round cells. Within channels there were atypical hyperchromatic cells, later identified as hematopoietic elements, including erythroid precursors and megakaryocytes. Diagnosis was confirmed by the endothelial/histiocytic phenotype of tumor and of the megakaryocytes. To the best of our knowledge, this case is the fourth description of LCA associated with extramedullary hematopoiesis or renal cell carcinoma. Additionally, recognition of megakaryocytes in these tumors is vital to avoid false positive malignant diagnoses. Further clinical and molecular studies of LCA are needed to understand the pathogenesis and association to visceral organ cancers to provide appropriate surveillance recommendations.