Isolated Congenital Asplenia in an Asymptomatic Patient: A Very Rare Diagnosis

Isolated congenital asplenia is a rare condition that mostly manifests in the early years, usually due to fatal systemic infections. In this paper, however, we present a case of a 36-year-old asymptomatic patient who was referred for suspected hyposplenism, with no history of splenectomy. There were no significant changes on physical examination. Blood analysis revealed leukocytosis and thrombocytosis as well as moderate anisopoikilocytosis and red blood cells with Howell–Jolly bodies. No spleen or other malformations were identified on imaging. Individuals with isolated congenital asplenia have an increased susceptibility to invasive infections and sepsis, with rapid clinical decline and a high mortality rate despite treatment. LEARNING POINTS: Isolated congenital asplenia is underdiagnosed in adults and should be excluded in patients with Howell–Jolly bodies in a peripheral blood smear, leukocytosis or/and thrombocytosis. Febrile episodes may present initially in these patients with mild symptoms; however, rapid progress to septic shock can occur. As a result, a delay in initiating broad-spectrum antibiotics may compromise their survival. Prevention with an individual vaccination plan and patient education is paramount.