Horseshoe adrenal gland in association with asplenia: presentation of six new cases and review of the literature

Abstract

Background. Asplenia syndrome is a form of heterotaxy characterized by bilateral right-sidedness. Congenital fusion of the adrenal glands ("horseshoe adrenal gland") is a less common feature of asplenia syndrome, most instances of which have been found at autopsy.

Purpose. To present clinical and imaging features of infants diagnosed with asplenia syndrome and horseshoe adrenal gland.

Materials and methods. Six infants with asplenia syndrome were identified as having a horseshoe adrenal gland. Medical records and imaging studies were reviewed to determine clinical presentation, associated anomalies, and outcome. The literature was reviewed for prior reports of horseshoe adrenal gland.

Results. Horseshoe adrenal gland was identified in five infants by sonography and one by CT, the latter confirmed by autopsy. In all cases, the horseshoe adrenal gland was pre-aortic. Besides features of asplenia syndrome, one infant also had associated vertebral anomalies and bilateral renal agenesis. Including the current cases, of 65 reported cases of horseshoe adrenal gland 34 (52%) were associated with asplenia, 24 (37%) with neural tube defects, 19 (29%) with renal anomalies, and 2 (3%) with Cornelia de Lange syndrome. Horseshoe adrenal gland has not been reported with polysplenia syndrome.

Conclusions. Horseshoe adrenal gland is a less common manifestation of asplenia that may be demonstrated by imaging. Horseshoe adrenal gland may be a differentiating feature between asplenia and polysplenia.