Littoral cell angioma of the spleen revealed by a Kasabach-Merritt syndrome in a 22-month-old child

Abstract

Introduction: Kasabach-Merrit syndrome (KMS) is characterized by the association of a vascular tumor, thrombocytopenia and potentially life-threatening coagulopathy. Observation: A 22-month-old child was referred to our center for incidental discovery of thrombocytopenia in a context of recurrent throat infections. Clinical examination showed petechial purpura, subicterus, no tumoral syndrome and good overall condition. His biological parameters showed regenerative hemolytic anemia (10.2 g/dL), thrombocytopenia (32 G/L), no schistocytes, moderate fibrinopenia and positive D-dimer test. The results of bone marrow analysis and autoimmune tests were normal. No treatment was undertaken given the absence of diagnosis and complication. The child was regularly followed-up in consultation. Complementary investigations ruled out Wilson's disease, thrombotic thrombocytopenic purpura and constitutional red blood cell disorders. The main hypothesis remained a thrombotic microangiopathy despite absence of schistocytes on repeated blood tests. Two months later, he was rehospitalized for acute clinical and biological worsening with splenomegaly and severe consumption coagulopathy leading to suspect a myeloproliferative syndrome, finally refuted. Steroids were started due to worsening hemorrhagic symptoms, daily transfusion requirements and increasing splenomegaly. Due to worsening health status and risk of threatening rupture, splenectomy was performed and histopathological analysis revealed a vascular lesion infiltrating the whole spleen, compatible with a littoral cell angioma. The child showed rapid clinical improvement and complete hematological normalization within 48 hours post-splenectomy. Conclusion: Littoral cell angioma is a very rare and benign vascular lesion which may be complicated by a lifethreatening KMS. This diagnosis should be suspected in patients presenting with splenomegaly and features of thrombotic microangiopathy.