Pituicytomas

Introduction

Pituicytomas are rare low-grade tumors (World Health Organization grade I) that are derived from pituicytes that are specialized glial cells of the neurohypophysis and infundibulum. Pituicytes are glial cells that function to support the hypothalamic-axons that secrete vasopressin and oxytocin and are comprised of oncocyctic, ependymal, and granular cell types. Their description is primarily limited to case reports, with approximately 80 reported in the literature. However, they closely resemble meningiomas and pituitary adenomas both clinically and radiologically, and therefore their surgical management is similar to these lesions. Surgical treatment, however, is challenging because of the hypervascularity of these lesions. In this chapter, we present a case of a patient with a suprasellar third ventricular pituicytoma.

Example case

Chief complaint: seizures

History of present illness

A 49-year-old, right-handed woman with a history of hypertension, anxiety, and depression presented after a seizure. She was working when she had an acute loss of consciousness with generalized tonic-clonic activity. She was taken to the emergency room where imaging was obtained ( Fig. 63.1 ). On further questioning, she complained of progressive confusion and diminished peripheral vision over several months.

Medications : Lithium, hydrochlorothiazide.
Allergies : No known drug allergies.
Past medical and surgical history : Tonsillectomy, hysterectomy.
Family history : No history of intracranial malignancies.
Social history: Accountant, 30 pack per year smoking history, occasional alcohol.
Physical examination : Awake, alert, oriented to person, place, time; Cranial nerves II to XII intact, except mild bitemporal hemianopsia; Moves all extremities with good strength.
Pituitary labs : Prolactin, insulin-like growth factor-1, cortisol, thyroid stimulating hormone/T4 all within normal limits.

	Luigi Maria Cavallo, MD, PhD, University of Naples Federico II, Naples, Italy	William T. Curry, MD, Massachusetts General Hospital, Boston, MA, United States	James J. Evans, MD, Tomas Garzon-Muvdi, MD, Thomas Jefferson University, Philadelphia, PA, United States	Tetsuro Sameshima, MD, PhD, Hamamatsu University, Hamamatsu, Shizuoka, Japan
Preoperative
Additional tests requested	MRI FIESTA and DTI Neuropsychological assessmentNeuroophthalmology (OCT, visual field)	CT/CT angiography Endocrine evaluation	CT/CT angiography EVD Endocrine evaluation	MRI FIESTA ASL MRI Pituitary hormonal evaluation Neuroophthalmology evaluation
Surgical approach selected	Right frontal endoscopic transventricular	Right frontal orbital craniotomy with left EVD	Endoscopic endonasal transtubercular, transplanum	Bifrontal basal interhemispheric
Other teams involved during surgery	None	None	ENT	None
Anatomic corridor	Right frontal transventricular	Translamina terminalis	Endonasal transtubercular, transplanum	Interhemispheric trans-lamina terminalis
Goal of surgery	Maximal resection	Maximal resection, resolution of hydrocephalus	Diagnosis, decompression, maximal resection	Total resection
Perioperative
Positioning	Supine neutral	Right supine with left 15-degree rotation	Supine without pins	Supine neutral
Surgical equipment	Surgical navigation EndoscopesNeuroport	Surgical navigation Surgical microscope	Surgical navigation Endoscope Ultrasonic aspirator	Surgical navigation Surgical microscope Ultrasonic aspirator
Medications	Steroids	Antiepileptics	Steroids	Steroids
Anatomic considerations	Foramen of Monro, aqueduct, third ventricular floor, infundibular recess, anterior commissure	Optic chiasm, ACA and branches, hypothalamus, pituitary stalk, mammillary bodies, walls of the third ventricle	Pituitary stalk, optic nerves, ICA, ACA, superior hypophyseal arteries	Optic nerves, hypothalamus, infundibulum
Complications feared with approach chosen	Pituitary dysfunction, hypothalamic disorder fornix injury, CSF leak	Injury to hypothalamus, optic apparatus	Brain retraction	Visual decline, diabetes insipidus, panhypopituitarism
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Linear	Frontotemporal linear	Fascia lata	Bicoronal
Bone opening	Right frontal mini-craniotomy	Left frontal burr hole, right frontotemporal/orbital roof	Sphenoid bone, sella, tuberculum sellae, planum sphenoidale	Bifrontal
Brain exposure	Right frontal lobe	Right frontotemporal	Anterior skull base	Bifrontal eccentric to the right
Method of resection	Right frontal mini-craniotomy based on navigation, small corticectomy, placement of neuroport in right lateral ventricle, bimanual debulking of tumor through foramen of Monro, dissection of tumor from third ventricular walls, third ventriculostomy	Left frontal burr hole, right frontotemporal craniotomy, removal of superior and lateral orbital rims and orbital roof, open dura, subfrontal dissection with identification of olfactory nerve and optic nerves, sharply open cisterns and proximal Sylvian fissure, identify chiasm/ACA/ACOM, dynamic retraction, debulk tumor and follow into third ventricle and dissect from lateral walls, aim for maximal resection	ENT to assist, nasoseptal flap harvest and placed in choanae, lateralization of bilateral middle turbinates, wide right sphenoidotomy, anterior skull base osteotomy of sella/tuberculum/planum using drills and punches, decompress optic nerves proximally, dura opened along midline, sharp dissection to expose anterior tumor, preserve blood vessels supplying optic chiasm and infundibulum, tumor cauterized and opened sharply and debulked followed by extracapsular microdissection, resect as much as possible, fascia lata harvested and button repair of dura is done and reinforced with nasoseptal flap and dural sealant	Bifrontal craniotomy, open dura, sagittal sinus ligation, interhemispheric opening, expose tumor identify key anatomic landmarks (optic nerve, pituitary stalk, hypothalamus), removal of tumor
Complication avoidance	Use port, avoid forniceal injury, avoid vascular injury inside the ventricle, mindful of floor of third ventricle, third ventriculostomy	EVD, cistern opening, dynamic retraction, follow tumor into third ventricle	Nasoseptal flap and fascia lata, large anterior skull base opening, internal debulking before extracapsular dissection, EVD placement	Bifrontal interhemispheric approach, identify and protect key anatomic landmarks
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Hypothalamic dysfunction, diabetes insipidus, hypopituitarism, visual decline	Cognitive decline, endocrine dysfunction, visual decline	CSF leak, hypopituitarism	Visual decline, hormonal dysfunction
Follow-up testing	Head CT immediately after surgery MRI within 48 hours after surgery Pituitary hormone analysis Visual field assessment	MRI 6 weeks after surgery if GTR, or MRI prior to discharge if STR	MRI 3 months after surgery Pituitary panel after surgery Sodium/SG if UOP >250 cc/hr for 2 hours	Hormonal evaluation CT immediately after and 1 day after surgery MRI 7 days after surgery
Follow-up visits	1 month after surgery with neuropsychology, endocrinology, and visual field testing	6 weeks after surgery with neurosurgery 1 month after surgery with endocrinology	1 week after surgery with ENT and neurosurgery	3 months after surgery
Adjuvant therapies recommended	Observation, repeat surgery or radiation therapy with recurrence	Observation, repeat surgery or radiation therapy with recurrence	Observation and possible radiotherapy with growth	Observation and repeat surgery with recurrence