Ectopic Posterior Lobe or Ectopic AVP Storage?

An ectopic posterior lobe, or more exactly, an ectopic storage of arginine-vasopressin AVP, previously antidiuretic hormone—can be primary or secondary. It results from the impossibility for AVP synthetized at the hypothalamic level to join its storage location at the posterior part of the sella. It signs that the pituitary stalk is unable to transport the hormone. It is present with growth hormone deficit along with a pituitary stalk agenesis or hypoplasia. The ectopic posterior lobe can grow with time and mimic a lesion of the suprasellar area. Acquired ectopic AVP storage may occur in three main situations: with sellar tumors, after transsphenoidal surgery, or more rarely after head trauma.