Co Existence of a Corticotroph Adenoma and a Multifunctional Pituitary Cyst

The co-existence of a corticotroph adenoma and a pituitary cyst is very unusual. We present the case of a 50-year-old female who presented with a Cushingoid phenotype, severe hypokalaemia, hyperglycaemia and hypertension. Urinary free cortisol was markedly elevated at 50 fold. ACTH levels were elevated at 121.4 pg/ml. She failed both the low and high dose dexamethasone suppression tests. The CRF test did not show a satisfactory rise in ACTH levels but the Inferior petrosal sinus sampling revealed a central to peripheral ACTH gradient highly suggestive of Pituitary dependant Cushing’s. MRI pituitary revealed a large cystic lesion with a small solid component. Computed Tomography (CT) of thorax abdomen and pelvis was normal. A trans-sphenoidal hypophysectomy was performed, during which a fine needle aspiration of the intra-cystic fluid was obtained. This showed markedly elevated pituitary hormone levels of ACTH (1399pg/ml), prolactin (353,084mIU/L), TSH (217IU/L) FSH (205mIU/ml) and GH (519 ng/ml) consistent with a multifunctional pituitary cyst. Neuropathology of the solid component confirmed a corticotroph adenoma. Post-operative am cortisol levels were persistently suppressed to less than 50 nmol/l with marked improvement in clinical features. This case highlights the challenges in the work up of Cushing’s syndrome and the limitations of diagnostic tests. The coexistence of a corticotroph adenoma and a multifunctional pituitary cyst is very unusual and to our knowledge has not been reported before.

Congenital pituitary cyst resulting in adipsic central diabetes insipidus and secondary hypernatremia in a cat

Case summary A 9-month-old intact female domestic mediumhair cat presented with a 5-month history of obtundation, lethargy, hypernatremia (181 mmol/l; reference interval [RI] 151–158 mmol/l), hyperchloremia (142 mmol/l; RI 117–126 mmol/l), azotemia (blood urea nitrogen 51 mg/dl; RI 18–33 mg/dl), creatinine 3.0 mg/dl (RI 1.1–2.2 mg/dl), hyperphosphatemia (8.3 mg/dl; RI 3.2–6.3 mg/dl) and total hypercalcemia (11.4 mg/dl; RI 9–10.9 mg/dl), with concurrent polyuria with adipsia. Neurologic evaluation revealed proprioceptive deficits, and this finding paired with a history of focal seizure-like activity despite improving sodium concentrations suggested a cerebrothalamic lesion. For this reason, and historical and biochemical findings consistent with adipsic diabetes insipidus (DI), MRI of the brain was performed, which revealed a lesion of the hypophyseal fossa consistent with a pituitary cyst. Given the patient’s age and the timeline of clinical signs, a congenital pituitary cyst was strongly suspected. The patient was managed initially with intravenous fluids to correct the hypernatremia, then managed for more than 4 years with topical ocular desmopressin acetate administration and free water administered through a feeding tube. This cat’s clinical diagnosis included a congenital pituitary cyst with subsequent central DI and primary adipsia. Relevance and novel information The clinical presentations of primary adipsia or central DI are both rare in cats. This is the first report to describe these conditions occurring in a cat owing to a congenital pituitary cyst and describes successful long-term management of this condition.

A case of central diabetes insipidus associated with a congenital cyst of the sella turcica in a young cat

Case summary A 1-year-old neutered male domestic shorthair cat was presented for polyuria and polydipsia which had progressed since adoption, 7 months previously. On admission, clinical examination did not reveal any remarkable features. Urinalysis showed marked hyposthenuria and calculated plasma osmolality was high, suggesting diabetes insipidus. A positive response to desmopressin administration appeared to confirm pituitary dysfunction. Brain MRI revealed a lesion compatible with a cyst or a neoplasm compressing the pituitary gland. A follow-up MRI performed 9 months later showed that the lesion was stable, which at first argued in favour of a congenital pituitary cyst. Intranasal administration of desmopressin was then used to achieve a long-term clinical response. Relevance and novel information Central diabetes insipidus (CDI) is a rare cause of polyuria and polydipsia in cats, resulting from inadequate or impaired secretion of antidiuretic hormone from the posterior pituitary gland. Recognised causes include head trauma, central nervous system (CNS) neoplasia, idiopathic CDI and congenital pituitary cysts. Apart from one cat with CNS lymphoma, the few previously reported feline cases have described CDI in young cats with a previous history of trauma, but brain imaging has rarely been performed to look for underlying anatomical abnormalities. This report describes the first case of CDI in a cat with a confirmed congenital pituitary cyst and, as in previous cases, demonstrates successful treatment with desmopressin.

SAT-105 The Natural History of Pituitary Cysts in Patients with Growth Hormone Deficiency and Idiopathic Short Stature

Background: The sequential follow-up of simple fluid-filled pituitary cysts (PC) has not been fully elucidated. In this study, we further report our follow up of PCs in a cohort of pediatric patients (PTs). Objective: To further analyze the sequential cyst volume (CV) change in short children. Patients and Methods: A pediatric endocrinology and neuroradiology center was queried for the presence of PCs. PTs who underwent multiple high resolution post-contrast MRIs (1mm slices) were subjects of this study. PTs with additional MRI abnormalities were excluded. Pituitary volumes (PV) and CVs were measured using the ellipsoid formula (LxWxH/2). The percentage of the gland occupied by the cyst (POGO) was measured and calculated. A cyst with a POGO ≤15% was defined as a small pituitary cyst (SPC), and a POGO >15% was defined as a large pituitary cyst (LPC). 34 PTs met inclusion criteria, all of whom were diagnosed with short stature (23 growth hormone deficient (GHD) PTs and 11 idiopathic short stature (ISS) PTs). All PTs were receiving GH during data collection. Results: The mean (MN) and median (MD) ages for these subjects were 10.7 yrs ±3.5 and 11.1 yrs, respectively (RSP). Of the 34 PTs, 24 PTs’ (71%) initial MRI demonstrated a SPC and 10 PTs’ (29%) initial MRI demonstrated a LPC. The MN and MD times between first and second MRIs were 1.23 yrs and 0.83 yrs RSP, with a range (RG) of 0.14 to 4.08 yrs. The MN and MD ΔCV for all PTs was 23.33% ±179.17% and -25.94% RSP, with a RG of -100.00% to 763.94%. The MN and MD ΔPOGO by the cyst for all PTs was 48.59% ±313.26% and -36.84% RSP, with a RG of -100.00% to 1734.79%. The MN and MD ΔCV for PTs with a SPC was 10.68% ±2.65% and 11.09% RSP, with a RG of -100.00% to 763.94%. The MN and MD ΔPOGO by the cyst for PTs with a SPC was 78.33% ±369.96% and -31.34% RSP, with a RG of -100.00% to 1734.79%. The MN and MD ΔCV for PTs with a LPC was -24.60% ±51.89% and -26.57% RSP, with a RG of -88.57% to 91.38%. The MN and MD ΔPOGO by the cyst for PTs with a LPC was -22.79% ±44.90% and -40.46% RSP, with a RG of -80.95% to 47.11%. Statistical analysis showed no significant %ΔCV or %ΔPOGO when comparing male vs. female, SPC vs. LPC, GHD vs. ISS, or pre-pubertal vs. pubertal PTs. Analysis of ΔPOGO of the 24 SPC PTs demonstrated that 4 (17%) of them developed into LPCs. Analysis of the 10 LPC PTs showed that 6 (60%) of them shrunk into SPCs, one of which re-enlarged into a LPC, and another of which fluctuated between LPC and SPC over a period of 7.34 yrs and 9 sequential MRIs. None of the PTs experienced significant sequelae related to their PCs. Conclusion: CV can change greatly over time, however few sequelae should be expected. LPCs tend to demonstrate major changes in size and should be tracked for CV change. A minority of SPCs will develop into LPCs. Prediction of change in CV over time requires more sequential data. Change in CV did not appear to be influenced by GH therapy.

Pituitary cyst presenting with hyponatremia and increased secretion of brain natriuretic peptide

✓ In most cases of pituitary cyst there are no clinical symptoms and the lesions are found incidentally. The authors report the case of a 60-year-old man with a pituitary cyst causing visual disturbance and hyponatremia. The patient presented with appetite loss and general fatigue. On admission, blood workup showed severe hyponatremia (112 mEq/L), and bitemporal hemianopsia was observed on neurological examination. Magnetic resonance imaging revealed an intra- and suprasellar region cystic mass extending to the frontal base and hypothalamic area. The serum level of brain natriuretic peptide (BNP) was elevated (92 pg/ml) with polyuria and excessive Na excretion. Transsphenoidal surgery was performed to drain the cyst. The cyst wall was partially excised and the cystic fluid was aspirated. The secretion of BNP normalized postoperatively, and the hyponatremia and visual symptoms resolved. Histological examination, including an electron microscopy study, confirmed the diagnosis of a simple cyst. This appears to be the first reported case of a pituitary simple cyst associated with hyponatremia and an elevated BNP level.