Sequence of right laterality with spleen: widening the spectrum of heterotaxy.

This is a report of two postmortem cases with sequence of right laterality and spleen. The presence of visceral right laterality and spleen is discordant with that indicated for the asplenia syndrome. The unusual presence of spleen, as in these two cases and previously reported cases, does not faithfully indicate the laterality sequence. Its recommended laterality should be defined as either right or left or considered heterotaxia instead of naming the anomaly based on asplenia or polysplenia syndrome.