Ectopic pituitary null cell adenoma arising from the infundibulum in the third ventricle: A successful endonasal transsphenoidal resection after long-term follow-up MR imaging – A technical note

Background: Since the origin and growth pattern of third ventricle ectopic pituitary adenoma (ectPA) remain unclear, its optimal surgical approach is debatable. Clinical presentation: We present a rare case of null cell pituitary adenoma arising from the pituitary infundibulum with long-term preoperative follow-up images. The tumor was resected gross-totally via an extended transsphenoidal approach. Conclusion: To our best knowledge, this is the first case with long-term preoperative follow-up images, which can bridge the knowledge gap in operations of third ventricle ectPA as following: (1) Truly third ventricle ectPA can exist, (2) the third ventricle ectPA extended into the sella turcica along the pituitary stalk, (3) this ectPA can arise from the suprasellar peri-infundibular ectopic pituitary cells or the pars tuberalis of the adenohypophysis, and therefore adhere to the optic chiasm, (4) thus neurosurgeons should take great care in resection of ectPA arising from the infundibulum, and (5) it can be resected through an endoscopic extended transsphenoidal approach. Keywords: Craniopharyngioma, Ectopic pituitary adenoma, Extended endoscopic transsphenoidal approach, Germ cell tumor, Neuroepithelial tumor, Null cell adenoma, Pars tuberalis, Suprasellar peri-infundibular ectopic pituitary cell

Unruptured medial paraclinoid internal carotid artery aneurysm embedded within symptomatic nonfunctioning pituitary giant adenoma: A high-risk comorbid pathology in transsphenoidal surgery and its countermeasures

Background: Injury of the internal carotid artery (ICA) in the cavernous portion is one of the most critical complications of transsphenoidal surgery (TSS), especially in cases of coexistence with a pituitary adenoma (PA) and ICA aneurysm. Case description: We present a rare case of unruptured medial paraclinoid ICA aneurysm (ICA-An) associated with symptomatic nonfunctioning giant PA. After endovascular coil embolization of the unruptured 4-mm saccular medial paraclinoid ICA-An, the patient underwent adenomectomy through an endoscopic endonasal TSS. During the bone resection over the right sellar floor near the right cavernous sinus, a tangle of packed coils in the treated medial paraclinoid ICA-An was observed immediately after a bite of a Kerrison rongeur. The dural layer over the coiled aneurysm had become thin to the point of transparency or complete absence. Careful inspection revealed that the bone hillock was formed by the medial paraclinoid ICA-An. Gross total resection of the adenoma was achieved without vascular injuries related to the coiled aneurysm despite postoperative transient right oculomotor paresis. Conclusions: This case conveys three important lessons about TSS: 1) coil embolization will manage a medial paraclinoid ICA-An as a sufficient preoperative procedure for TSS; 2) a medial paraclinoid ICA-An can appear directly under the sellar floor as an apparent extradural aneurysm; and; 3) surgeons should take great care in procedures near a coil-embolized medial paraclinoid ICA-An because the aneurysmal wall can be thin to the point of transparency. Keywords: Medial paraclinoid internal carotid artery aneurysm, Coil embolization, Extradural unruptured aneurysm, Pituitary giant adenoma, Endoscopic endonasal transsphenoidal surger