Background: Pituicytoma is a very low-grade glioma that originate in the neurohypophisis and infundibulum.
Objective and hypotheses: Describe diagnosis and treatment of associated pituicytoma and ACTH-secreting adenoma in a 6-year-old girl.
Method: Case report and literature review.
Results: We report the case of a 6-year-old presented with growth failure and associated weight gain, premature pubarche, and hyperthichosis. Cushings syndrome was biochemically diagnosed on the basis of loss of serum cortisol circadian rhythm, i.e. an elevated sleeping midnight cortisol level of >50 mmol/l and failure of serum cortisol suppression to <50 mmol/l during an overnight 1 mg dexamethasone and successive high-dose suppression test. MRI scanning displayed a focal area of altered signal (bright on T2-sequence) in the middle and superior portion of pituitary gland, suggestive for an ACTH-secreting adenoma. Bilateral simultaneous inferior petrosal sinus sampling was performed. A central to peripheral ACTH ratio was not indicative of central ACTH secretion and an inter-petrosal sinus gradient <1.4 was suggestive of a midline lesion. The patient underwent excision of a small, soft mass by endoscopic transsphenoidal approach. Unexpectedly, the definite postoperative histopathological diagnosis of the removed tumor was pituicytoma and not pituitary adenoma. Hence, the microadenoma responsible for Cushings disease was not yet removed. For persistent hypercortisolism, the patient underwent a second MRI that confirmed the presence of an intraglandular small area of altered signal in the same region. A second transsphenoidal operation was performed; histological examination of the removed lesion revealed a pituitary adenoma ACTH-secreting.
Conclusion: Pituicytoma is a very rare tumor: 65 cases are described in literature, with only three children affected. Coincidence of pituicytoma and pituitary-dependent Cushings disease was only reported in an adult man. It is difficult to explain this extremely rare association, that represented a diagnostic and therapeutic challenge.
18 Sep 2014 - 20 Sep 2014