Introduction
Ectopic pituitary adenomas (EPAs) are isolated adenomas located outside
the sella turcica with a normal intrasellar pituitary gland. EPAs are
thought to be extremely rare tumours [1]. The location of EPAs can
vary, with approximately 60% of reported cases found in the sphenoid
sinus and suprasellar region, 30% in the clivus, nasal cavity,
parasellar region, cavernous sinus, and sphenoid wing [2]. The
origin of EPAs can take one of three forms, with the most common being
adenomas derived from residual cells of Rathke’s pouch which persist
along the developmental pathway of the anterior pituitary gland.
Clinical manifestations of EPAs usually depend on hormonal activity and
involvement of adjacent structures. For example, tumours extending into
the cavernous sinus or clivus can compress cranial nerves and cause
visual disturbances and facial paresthesia, while sphenoid sinus EPA can
result in headache, nasal obstruction and CSF leak [2]. The
diagnosis and management of EPAs can be challenging and usually requires
strong clinical suspicion along with magnetic resonance imaging (MRI)
findings, including normal pituitary gland, and is confirmed by
pathological studies. Computerized Tomograph (CT) can also provide
useful information such as invasion of the sphenoid sinus, and therefore
helps plan the endoscopic trans-sphenodial surgery, which is considered
the most appropriate management approach [3, 4]. In this case, we
present a clival ectopic pituitary prolactinoma.