RGD uses the Human Disease Ontology (DO, https://disease-ontology.org/) for disease curation across species. RGD automatically downloads each new release of the ontology on a monthly basis. Some additional terms which are required for RGD's curation purposes but are not currently covered in the official version of DO have been added. As corresponding terms are added to DO, these custom terms are retired and the DO terms substituted in existing annotations and subsequently used for curation.
An orbit rhabdomyosarcoma that is characterized by ill-defined aggregates of poorly differentiated malignant cells that are loosely arranged and separated into irregular ovoid spaces by thin fibrovascular septa in an alveolar pattern which is absent in the solid form. (DO)