A nonspecific tumor-like inflammatory lesion in the ORBIT of the eye. It is usually composed of mature LYMPHOCYTES; PLASMA CELLS; MACROPHAGES; LEUKOCYTES with varying degrees of FIBROSIS. Orbital pseudotumors are often associated with inflammation of the extraocular muscles (ORBITAL MYOSITIS) or inflammation of the lacrimal glands (DACRYOADENITIS). The disease is orbital plasma cell granuloma (Experimental Factor Ontology id EFO_1001077). Also known as: Idiopathic orbital inflammation, Inflammatory pseudotumor of orbit (disorder), Orbital Pseudotumor, Pseudotumor of orbit.