Brain magnetic resonance imaging (MRI) scans reveal incidental pars intermedia/Rathke cleft pituitary cysts or cyst-like structures so frequently that the American College of Radiology (ACR) has developed management guidelines for adult patients. Now, radiologists at the University of Missouri Hospital/Women’s and Children’s Hospital in Columbia have conducted a study to determine the prevalence of these incidental findings in children, and to assess for endrocrinopathy and related follow-up.
The authors, who published their study results in the July 27, 2019, online edition of Pediatric Radiology, identified 232 brain MRI scans performed during a 90-day period that had been reported as either normal, unremarkable, or unremarkable with incidental isolated pituitary cystic lesions. The exams were ordered for pediatric patients presenting with headache (36%), seizure (31%), developmental delay or autism (4%). Fewer patients also presented with facial palsy, hearing loss, or altered mental status.
Studies were performed on both 1.5T (42%) and 3.0T (58%) MRI scanners. The authors reviewed three-dimensional (3D) volumetric T1-spoiled gradient echo and axial T2-weighted sequences, evaluating pituitary glands for the presence, size, and signal characteristics of cysts. They measured the volumes of the 134 cyst or cyst-like structures identified in axial, coronal, and sagittal planes.
Led by Eman S. Mahdi, MD, the researchers reported that 90% of the cysts were hypointense on T1-weighted images and that 79% were isointense on T2-weighted images relative to the adenohypophysis. They ranged in linear measurement from 0.4 to 12.3 mm, with a mean of 3.6 mm.
There was no significant difference in cyst prevalence based on magnetic field strength. There was no association between the presence of cyst and cyst-like lesions and a diagnosis of endocrinopathy.
The authors had also stratified the patients into five age categories. Each age group had a similar percentage of incidentally detected cysts, from 50% in infants to 60% in middle childhood.
“Small, cuboid lesions that are largest in transverse/craniocaudal and smallest in anteroposterior dimensions are especially common and should be considered a normal variant,” they wrote. “Awareness of the frequency and appearance of these incidental benign pituitary cysts and cyst-like structures is important to decrease expensive and unnecessary evaluations.”
The authors state that follow-up typically is not required in the absence of associated symptoms or excessive size.
Incidentally detected pituitary cysts in children common on MRI. Appl Radiol.