J-shaped sella is/are seen in:

D i.e. All i.e. Mucopolysaccharidoses, Achondroplasia, Optic chiasm glioma, Neurofibromatosis I, Hydrocephalus Sella turcica is a cup shaped depression in the central basisphenoid bone that contains the pituitary gland and inferior pa of the infundibular stalk. Flattened tuberculum sellae with a prominent sulcus chiasmaticus are the factors responsible for sella looking J shaped on lateral skull x-ray. The normal dorsal sellae forms the loop of J. J shaped sella turcica is seen in : Mn - "COMAND" or "CONMAN Must Die" - Chronic hydrocephalusQ (d/t enlarged anterior aspect of 3rd ventricle) - Osteogenesis imperfecta, Optic (chiasm) gliomaQ (glioma Dorsum -- may be bilateral 1/t W or omega shped sella; if chiasmatic sellae sulcus is very depressed). - MucopolysaccharidosesQ (eg Hurler syndrome >> Hunter syndrome) - AchondroplasiaQ - NeurofibromatosisQ (type 1 is usually a/w slowly growing optic glioma which may extend upto chiasma); Normal variant (5%) - Dysostosis multiplex (defect in carbohydrate metabolism). - Hajdu-Cheney syndrome & congenital hypothyroidism are other rare causes