Endocrine Abstracts

Introduction: Congenital pituitary stalk interruption syndrome (PSIS) is a rare condition, characterized by the triad (not always complete): absence/hypoplasia of the pituitary stalk, hypoplasia/aplasia of the anterior pituitary and absence or ectopy of the posterior pituitary high signal intensity, on magnetic resonance imaging (MRI). PSIS implies a permanent GH deficiency, in 77% associated with other pituitary hormones deficiencies. The aetiology remains uncertain, but some genes have been implied. Rathke’s cleft cysts (RCC) present typically as intrasellar and/or suprasellar benign lesions, the most common incidentally discovered sellar lesions (few mm to 2 cm diameter), with a female:male ratio of 1:3.

Clinical case: A 18-year-old boy was referred from the Pediatric Endocrinology Department, with GH deficiency and central hypothyroidism (CH) diagnosed at the age of 9. Recombinant GH therapy had already been suspended (after 9 years; target height 170 cm achieved) and he was only on levothyroxine. MRI at 8 years of age had revealed a small pituitary gland, absence of the high signal intensity in the posterior pituitary, pituitary stalk atrophy, and a small pineal cyst. Reevaluation showed no other pituitary hormone deficiencies. There were no symptoms of diabetes insipidus. Follow up MRI (23 years old) showed a 7 mm sellar and suprasellar cystic lesion, suggestive of RCC, causing pituitary compression, pituitary stalk hypoplasia, and absence of posterior pituitary bright spot in T1. Until now, 1 year later, his clinical condition remains stable.

Conclusions: In this clinical case, a patient with PSIS had a RCC incidentally diagnosed in a follow up MRI. Paediatric cases have been reported but rarely, as RCCs grow slowly, becoming clinically evident later in life. Symptoms are uncommon and associated with mass effects. As there is compression of the pituitary gland, closed follow-up must be kept. Genetic tests results are pending.