Spontaneous Resolution of Pituitary Cystic Lesion

Differentiating between cystic lesions of pituitary gland may be challenging. Usual differentials are cystic pituitary adenoma (cPA) and Rathke’s cleft cyst (RCC). Diagnostic certainty of magnetic resonance imaging (MRI) is limited in the absence of usual suggestive features. Furthermore, RCC can co-exist with approximately 2% of pituitary adenomas. Over time, these cystic lesions may remain static, resolve spontaneously, or result in symptomatology relating to mass effect and/or hormonal disruption. In cases of an asymptomatic lesion being found incidentally, little is known about how it may progress, raising question whether to proceed with surgical management or follow-up. We a present case of a spontaneously resolving pituitary cystic lesion with imaging features more suggestive of cPA than RCC, for which watchful waiting proved a successful treatment strategy. The current case serves as a reminder that small cystic lesions can be followed-up with spontaneous resolution and should be offered active treatment only when clinically required.