Seen on X Ray image of skull. Used for diagnostics of pitutary gland.
The J-shaped sella, seen on the lateral view of the skull, is caused by flattening of the tuberculum sellae, forming the stem of the J. The normal dorsum sellae forms the loop of the J. The extension of the anterior aspect of the sella is distinguished from the true pituitary fossa by the tuberculum sellae.
Causes (Diffrential Diagnosis) of J-shaped Sella (mnemonic: CONMAN)
- Chronic hydrocephalus
- Optic glioma, Osteogenesis imperfecta
- Normal variant (In 5% of normal children. Normalizes later in life.)
Other rare cause: Hajdu-Cheney syndrome: Rare disorder of bone metabolism. The diagnosis is made by finding acroosteolysis with any three of the following: Wormian bones, open skull sutures, platybasia, micrognathia, mid-facial flattening, premature loss of teeth, coarse hair, and short stature.
Image demonstrating Normal vs J shaped sella – diagrammatic representation.