Langerhans Cell Histiocytosis of Orbit Etiology: uncontrolled monoclonal proliferation of Langerhans cells Imaging: lateral-inferior quadrant mass Radiology Cases of Langerhans Cell Histiocytosis of Orbit Coronal CT with contrast of the orbits in bone (above left) and soft tissue (above right) windows show bony destruction in the superolateral aspect of the orbit caused by a soft tissue mass. Coronal T1 MRI without (below left) and with contrast (below right) of the orbits better show the soft tissue mass superolateral to the left orbit which enhances avidly. Sagittal T1 MRI without contrast (above left) of the brain shows absence of the posterior pituitary bright spot. Sagittal (above right) and coronal T1 with contrast (below left) show a thick and enhancing pituitary stalk. Axial T1 with contrast (below right) again shows the thick enhancing pituitary stalk and enhancing lesions in both sphenoid wings and in the left orbit.