BACKGROUND: Isolated congenital asplenia is a poorly understood and rare form of primary immunodeficiency, often associated with life-threatening infections.

CASE REPORT: We encountered a unique case of a 22-year-old asplenic male who presented with severe iron-deficiency anemia secondary to occult gastrointestinal bleeding since age 15. Our extensive work-up confirmed jejunal arteriovenous malformations as the source of the bleed. Six months after the treatment, the patient has reported no further episodes of gastrointestinal bleeding and his hemoglobin has remained stable.

CONCLUSIONS: A comprehensive literature review confirmed that this is the first reported case of adult congenital asplenia associated with arteriovenous malformation in the United States. The relationship of isolated congenital asplenia and arteriovenous malformation-associated bleeding remains unknown at this time; we postulate that this may be a congenital syndrome on its own. Obscure bleeding in the presence of rare anomalies such as asplenia should be investigated as one of the important causes of unexplained intestinal arteriovenous malformations.

Keywords: Arteriovenous Malformations, Congenital Abnormalities, heterotaxy syndrome, Spleen