The prevalence and volumetry of pituitary cysts in children with growth hormone deficiency and idiopathic short stature

The evolution of pituitary cysts in growth hormone-treated children

OBJECTIVES

We have previously shown that pituitary cysts may affect growth hormone secretion. This study sought to determine cyst evolution during growth hormone treatment in children.

METHODS

Forty-nine patients with short stature, a pituitary cyst, and at least two brain MRI scans were included. The percent of the pituitary gland occupied by the cyst (POGO) was calculated, and a cyst with a POGO of ≤15% was considered small, while a POGO >15% was considered large.

RESULTS

Thirty-five cysts were small, and 14 were large. Five of the 35 small cysts grew into large cysts, while 6 of the 14 large cysts shrunk into small cysts. Of 4 cysts that fluctuated between large and small, 3 presented as large and 1 as small. Small cysts experienced greater change in cyst volume (CV) (mean=61.5%) than large cysts (mean=-0.4%). However, large cysts had a greater net change in CV (mean=44.2 mm³) than small cysts (mean=21.0 mm³). Older patients had significantly larger mean pituitary volume than younger patients (435.4 mm³ vs. 317.9 mm³) and significantly larger mean CV than younger patients (77.4 mm³ vs. 45.2 mm³), but there was no significant difference in POGO between groups.

CONCLUSIONS

Pituitary cyst size can vary greatly over time. Determination of POGO over time is a useful marker for determining the possibility of a pathologic effect on pituitary function since it factors both cyst and gland volume. Large cysts should be monitored closely, given their extreme, erratic behavior.

Growth hormone replacement therapy: is it safe to use in children with asymptomatic pituitary lesions?

OBJECTIVES

Small pituitary cysts are commonly discovered on pediatric brain magnetic resonance imagings (MRIs), particularly in patients with growth hormone deficiency (GHD). We examined the need for operative management in children with these masses as well as the effect of growth hormone replacement (GHR) on these lesions.

METHODS

This was a retrospective review of pituitary protocol MRIs conducted in children 0-19 at a single center between April 2010-November 2020. Sex, indication for initial MRI, volume, and whether surgery was performed was determined. Records were reviewed to determine whether GHD was present and treatment with GHR documented. For patients with subsequent MRIs, volume on most recent scan was calculated.

RESULTS

Of the 101 children with cysts, 25 had laboratory-confirmed GHD and 76 did not. GHD patients had a higher mean age compared to no growth hormone deficiency (NGHD) cohort (11.2 and 8.4 years, respectively; p=0.02) and a larger proportion of males (p<0.001). The mean cyst volume on initial MRI was not significantly smaller in patients with GHD (0.063 ± 0.012 cm³) vs. those without GHD (0.171 ± 0.039 cm³, p=0.11). Of the 21 GHD patients who received GHR and had follow-up MRIs, 10 had no change in pituitary cyst size, two had cysts that shrank, and seven disappeared. The remaining two cysts enlarged an average of 0.061 ± 0.033 cm³. Zero GHR recipients required surgical intervention.

CONCLUSIONS

Small sellar cysts discovered incidentally on imaging in children are unlikely to require surgical intervention. GHR does not appear to significantly enlarge these pediatric pituitary lesions and is safe for use.

A novel diagnostic tool for the evaluation of hypothalamic-pituitary region and diagnosis of growth hormone deficiency: pons ratio

Backgrounds Limitations in the evaluation of the pituitary size and changes according to pubertal status make its validity questionable. Recently, in a small-scale study, pons ratio (PR) has been suggested as a more sensitive tool for diagnosis and etiological evaluation of growth hormone deficiency (GHD). The aim of the study is to evaluate the diagnostic value of PR in the diagnosis of GHD. Methods We retrospectively evaluated the pituitary magnetic resonance imaging (MRI) of 133 patients with a diagnosis of GHD. Primary axis (PA) was assigned as a line crossing the mid-sagittal dorsum sella and fourth ventricle. PR was defined as the pons height above the PA divided by total pons height. The PR of patients with GHD was compared to subjects without GHD. Results Study included 133 patients with GHD and 47 controls. In total, 121 (91%) patients had isolated GHD and 12 (9%) patients had multiple pituitary hormone deficiency. The PR of the patient group (mean: 0.32 ± 0.89; range: 0.14-0.63) was significantly higher than controls (mean: 0.26 ± 0.067; range 0.19-0.44) (p: 0.000). The optimal cut-off value of PR for GHD diagnosis was 0.27 (sensitivity 71% specificity 56%). There was a negative correlation between anterior pituitary height (APH)-SDS and PR (p: 0.002; r: -0.27). APH was increased, but PR remained unchanged in pubertal patients (p: 0.089). Conclusions PR measurement is a noninvasive, practical method with a cost-benefit clinical value. As it is not affected by pubertal status, PR is potentially a more sensitive tool for evaluation of pituitary gland in GHD patients compared to APH.