Imaging of Rathke's Cleft Cysts: Criteria for a Differential Diagnosis

Abstract

Rathke's cleft cysts are a congenital disorder of the pituitary gland and derive from abnormalities of the development of the adenohypophisis. The variability of the MRI signal of Rathke's cleft cyst hampers the differential diagnosis with the other cystic lesions of the pituitary gland. Nevertheless a comparison between the various findings reported from by author we reviewed indicates that a description of useful criteria for a differential diagnosis is possible. We suggest that the mean age at onset, the symptoms, the magnetic signal intensity, the location within the gland, the relations with the surrounding structures and the behaviour after contrast injection should always be considered in the diagnostic work-up of Rathke 's cleft cysts. There is no consensus in the literature on the correct therapeutic protocol. We suggest following up a small asymptomatic Rathke's cleft cyst (except mucoid cysts) because they do not generally enlarge. Surgery is instead the gold standard for symptomatic Rathke's cleft cysts, large Rathke's cleft cysts and mucoid Rathke's cleft cysts. Mucoid Rathke's cleft cysts, even when small, may cause an intense pituitary inflammation which could lead to irreversible endocrine dysfunction.

Rathke Cleft Cyst with a Coexisting Gonadotropin Producing Pituitary Adenoma

“…Rathke cleft cysts are benign, epithelial-lined cystic remnants of Rathke pouch and remain asymptomatic in the majority of people [7]. In cases of symptomatic Rathke cleft cyst, the common symptoms are headache, visual disorder, endocrine dysfunction probably caused by the mass effect on the adjacent structures [1] Rathke cleft cysts have been found incidentally in 11% -33% of post-mortem examinations, and were associated with 1.7% -2.1% of the pituitary adenoma cases [1]- [3] [8]. The relationship between Rathke cleft cyst and pituitary adenoma is still controversial [1] [3].…”

“…Rathke cleft cyst (RCC), first described by Luschka in 1860 [1] [2], is thought to arise from incomplete obliteration of the lumen of Rathke pouch. This embryonic structure develops as a rostral outpouching of the stomodeum or primitive oral cavity during the third or fourth week of gestation.…”

“…It has an anterior and posterior wall, as well as a central embryonic cleft. The anterior wall of the pouch proliferates to form the anterior lobe of the pituitary gland and the pars tuberalis; the posterior wall becomes the pars intermedia [1]- [5]. The residual lumen of the pouch is reduced to the narrow Rathke cleft, which usually regresses completely.…”

“…The residual lumen of the pouch is reduced to the narrow Rathke cleft, which usually regresses completely. The cells of the anterior pituitary lobe, from which pituitary adenomas develop, are also derived from the cells of Rathke pouch [1]- [3]. Although RCC and pituitary adenoma have a shared ancestry, they rarely occur coincidentally [2] [3] [5] [6].…”