Persisting embryonal infundibular recess

Abstract

Persisting embryonal infundibular recess (PEIR) is a rare anomaly of the third ventricular floor that has an unclear pathogenesis. In all 7 previously described cases, PEIR was present in adult patients and was invariably associated with hydrocephalus and, in 4 reported cases, with an empty sella. These associated findings led to speculations about the role of increased intraventricular pressure in the development of PEIR. In the present case, PEIR was found in a 24-year-old man without the presence of hydrocephalus or empty sella. Disorders of pituitary function had been present since childhood. Magnetic resonance imaging revealed a cystic expansion in an enlarged sella turcica. A communication between the third ventricle and the sellar cyst was suspected but not apparent. During transcranial surgery, the connection was confirmed. Later, higher-quality MR imaging investigations clearly showed a communication between the third ventricle and the sellar cyst through a channel in the tubular pituitary stalk. This observation and knowledge about the embryology of this region suggests that PEIR may be a developmental anomaly caused by failure of obliteration of the distal part of primary embryonal diencephalic evagination. Thus, PEIR is an extension of the third ventricular cavity into the sella. Although PEIR is a rare anomaly, it is important to identify when planning a procedure on cystic lesions of the sella. Because attempts at removal using the transsphenoidal approach would lead to a communication between the third ventricle and the nasal cavity, a watertight reconstruction of the sellar floor is necessary.

A Case of Presumably Rathke’s Cleft Cyst Associated with Postoperative Cerebrospinal Fluid Leakage through Persisting Embryonal Infundibular Recess

“…The distal part of the infundibulum is obliterated and is referred to as the infundibular stem. 10) By the time the fetus reaches 45 mm in length, the distal part of the infundibular sac is obliterated by cellular proliferation 1,2) and ultimately differentiates to form the obliterated part of the infundibulum and the posterior pituitary lobe. 11) In some mammals, such as the cat or the bear, the entire embryonal infundibular recess persist extending through the tubular pituitary stalk to the posterior lobe of the pituitary.…”

“…The authors of previous publications proposed that the increased intraventricular pressure developed PEIR, because of the presence of hydrocephalus in the majority of reported patients with PEIR. 1,2,4–8) On the other hand, Steno et al experienced a case of PEIR without hydrocephalus and proposed the etiology of PEIR is a developmental anomaly caused by lack of obliteration of the distal part of the primary diencephalic evagination. 1) In the present case, PEIR was not accompanied by hydrocephalus, which supports the latter hypothesis.…”

“…1,2,4–8) On the other hand, Steno et al experienced a case of PEIR without hydrocephalus and proposed the etiology of PEIR is a developmental anomaly caused by lack of obliteration of the distal part of the primary diencephalic evagination. 1) In the present case, PEIR was not accompanied by hydrocephalus, which supports the latter hypothesis. The relationship between PEIR and Rathke's cleft cyst remains unclear and there is no reported case of PEIR associated with Rathke's cleft cyst.…”

“…Eight cases have been reported, 1–8) of which 7 cases were accompanied with hydrocephalus, therefore, increased intraventricular pressure is thought to play an important role. In the four reports, 2,5,7,8) PEIR was verified by ventriculography, and in the other three reports 1,4,6) by magnetic resonance (MR) imaging. We present a case of presumably Rathke's cleft cyst associated with postoperative cerebrospinal fluid leakage through PEIR not accompanied with hydrocephalus after endoscopic endonasal transsphenoidal surgery.…”

Persisting embryonal infundibular recess masquerading as a nasal mass

“…This is a rare condition with only eight cases reported in world literature. [ 1 ] In previously reported cases, the defect was demonstrated in the third ventricular floor, with the sac descending inferiorly only up to the sella. However, this is the first case of PEIR, with the sac descending into the nasal cavity as pulsatile nasal mass.…”