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.
Differential considerations include:
- Normal variant: In 5% of normal children. Normalizes later in life.
- Hypothyroidism:
- Slowly growing parasellar tumor: Optic glioma (e.g., in neurofibromatosis type 1).
- Mucopolysaccharidoses: Classically described in Hurler syndrome, but can be seen in the other mucopolysaccharidoses. The case above is from a patient with Hunter syndrome.
- Mild arrested hydrocephalus:
- 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.
References
- Merle P, Georget AM, Goumy P, Jarlot D. Primary empty sella turcica in children. Report of two familial cases. Pediatr Radiol. 1979 Oct;8(4):209-12.
- Wren MW. Significance of the so-called J-shaped sella in the diagnosis of intracranial aneurysm. Br J Ophthalmol. 1969 May;53(5):307-9.
Thank you so much for that post.
ReplyDeleteawesome concepts!!!! just the thing i was looking for
ReplyDeleteThank you. Can you say wheter it can be caused by the tumor in third ventricle? And what is the link? What is the difference betwen J-shaped dorsum sella and erosion of it?
ReplyDeleteNot sure about the third ventricle tumor. A J-shaped sella suggests a slow process that slowly and smoothly changes the shape of the dorsum sella. Although the terminology can vary, erosion **usually** suggests a more aggressive process. However, "pressure erosion" can also be used to describe a slow process. A picture is worth a million imprecise words :)
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