Cushing pituitary adenoma

Introduction

Cushing syndrome is caused by excess cortisol, in which the most common cause of endogenous Cushing syndrome is Cushing disease. ^, Cushing syndrome can be diagnosed with late night salivary cortisol, 24-hour urine free cortisol, and/or low-dose dexamethasone suppression in which two of three are confirmatory. ^, Cushing disease is caused by a pituitary adenoma that secretes adrenocorticotropic hormone (ACTH), which stimulates secretion of cortisol by the adrenal glands and leads to hypertension, diabetes, obesity, osteoporosis, and peripheral vascular disease, among others. ^, Cushing disease has a prevalence of 39.1 per million people, with an annual incidence of 1.2 to 2.4 per 1 million people per year. ^, Untreated Cushing disease is associated with two- to fivefold increased mortality. ^, The majority (90%) of Cushing disease are diagnosed when they are microadenomas (< 1 cm), in which the median diameter is 6 mm at discovery. ^, In this chapter, we present a case of a patient with a Cushing pituitary macroadenoma.

Example case

Chief complaint: headaches, weight gain

History of present illness

A 32-year-old, right-handed woman with no significant past medical history who presented with headaches and weight gain. For the past 2 years, she had gained 30 to 40 pounds, despite healthy diet and frequent exercise. She had noted that her face was fuller, as well as facial hair growth and acne. She saw her endocrinologist and had elevated urinary and salivary cortisol and failed a low-dose dexamethasone suppression test. A brain MRI was done and showed a pituitary lesion ( Fig. 59.1 ).

Medications: None.
Allergies: No known drug allergies.
Past medical and surgical history: None.
Family history: No history of intracranial malignancies.
Social history: Nurse, no smoking or alcohol.
Physical examination: Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact, visual fields full to confrontation; No drift, moves all extremities with full strength.
Pituitary labs: Elevated salivary and urinary cortisol and failed low-dose dexamethasone suppression test; prolactin, thyroid stimulating hormone/T4, insulin-like growth factor-1 all within normal limits.

	Nelson M. Oyesiku, MD, PhD, Joseph Quillin, MD, Emory University, Atlanta, GA, United States	Henry W. S. Schroeder, MD, PhD, University of Greifswald, Greifswald, M-V, Germany	Tony Van Havenbergh, MD, PhD, GasthuisZusters Antwerpen, Antwerpen, Belgium	Gabriel Zada, MD, University of Southern California, Los Angeles, CA, United States
Preoperative
Additional tests requested	Neuroophthalmology evaluation (visual fields, OCT) Endocrinology evaluation ENT evaluation Pregnancy test High-resolution T2 MRI	Neuroophthalmology evaluation (visual fields) CT maxillofacial Anesthesiology evaluation	Neuroophthalmology evaluation (visual fields) Endocrinology evaluation	Neuroophthalmology evaluation (visual fields) Endocrinology evaluation with full pituitary panel High-resolution MRI
Surgical approach selected	Endoscopic transnasal transsphenoidal and transtubercular with lumbar drain	Endoscopic endonasal transsphenoidal and transtubercular	Endoscopic endonasal	Endoscopic endonasal transsphenoidal
Other teams involved during surgery	ENT	ENT	ENT	None
Anatomic corridor	Transnasal transsphenoidal and transtubercular	Transnasal transsphenoidal and transtubercular	Transnasal transsphenoidal	Transnasal transsphenoidal
Goal of surgery	Gross total resection, biochemical cure	Gross total resection, biochemical cure	Gross total resection, biochemical cure	Maximal safe tumor removal
Perioperative
Positioning	Supine with pins, 10-degree right rotation	Supine with pins, right rotation and slight extension	Supine with slight right turn with pins	Supine no pins
Surgical equipment	Lumbar drain Surgical navigation 0- and 30-degree endoscopes Cranial Doppler Ultrasonic aspirator	Endoscopes	Surgical navigation Endoscopes Tissue shaver	Surgical navigation Endoscopes Microdoppler
Medications	None	Steroids	Steroids	None
Anatomic considerations	Cavernous carotid arteries, optic nerves, infundibulum, ACOM	Pituitary stalk, cavernous carotid arteries	ICA, pituitary stalk, optic structures, cavernous carotid artery	Carotid arteries, pituitary gland, optic apparatus
Complications feared with approach chosen	ICA/ACA injury, hypothalamic injury, diabetes insipidus, hypopituitarism, CSF leak	Damage to olfactory mucosa, injury to ICA and pituitary stalk, CSF leak	ICA injury, CSF leak, damage to pituitary gland	Vision loss, cerebral edema, neurologic deficits, seizures
Intraoperative
Anesthesia	General	General	General	General
Skin incision	None	None	None	None
Bone opening	+/– right middle turbinate, wide sphenoid osteotomy, posterior ethmoidectomy, removal of sella from cavernous to cavernous sinus, removal of tuberculum	Sphenoid osteotomy, intersinus septations, sellar floor, tuberculum, adjacent planum	Posterior nasal septum, anterior wall of sphenoid sinus, sella	Wide sphenoid osteotomy
Brain exposure	Sella from cavernous to cavernous sinus and tuberculum removal	Sella, tuberculum, adjacent planum	Sella	Sella from cavernous to cavernous sinus
Method of resection	Lateralize inferior turbinates, +/– resection of right middle turbinate, partial resection of inferior aspect of superior turbinate, posterior septectomy, wide sphenoid sinus opening, resection of sphenoid rostrum/bilateral posterior ethmoid air cells, raise large right Hadad nasoseptal flap, removal of sellar face from cavernous to cavernous sinus, drill out clival recess, thin sphenoid tuberculum past limbus dural fold and reflect bone away, open dura, extracapsular dissection, assessment for residual tumor nests and CSF leak, retrieval of nasoseptal flap, Nasopore	Lateralization of all turbinates, harvest right nasoseptal flap and storage in nasopharynx, reverse flap on left, open sphenoid sinus and drill all septi, removal sellar floor/tuberculum/adjacent planum, incise dura, resect tumor with curettes and forceps, open suprasellar dura to access suprasellar component if no descent, inspect cavity with various angled scopes, pack fat in the sellar area, position nasoseptal flap with fibrin glue, nasal tamponades	Binostril approach, resection of posterior nasal septum, wide opening of anterior wall of sphenoid sinus, open the anterior bony part of the sella, H-shaped dural opening, sharp dissection of tumor from normal pituitary, dissect starting at lower part of the tumor allowing the diaphragm to descend downward, use curettes if necessary, endoscopic inspection of resection cavity for residual tumor, no tampons in nostrils	Lateralization of bilateral middle turbinates, widening of sphenoid ostium, harvesting of rescue nasal mucosal flaps, removal of sphenoid rostrum, removal of sphenoid sinus septations, verification of sellar floor, removal of sellar floor, microdoppler to confirm carotid arteries and navigation for tumor boundaries, dural opening, tumor debulking with curette, angled endoscopes to look into suprasellar cistern, Valsalva to evaluate for CSF leak, repair of CSF leak with autologous gat or fascia lata, alloderm, or nasoseptal flap, medialization of turbinates
Complication avoidance	Harvesting nasal septal flap, wide sellar opening, extracapsular dissection, close attention to right cavernous sinus, inspection with various scopes for residual and CSF leaks	Harvesting nasal septal flap, inverted flap on the contralateral side, wide bony opening of sella/tuberculum/planum, inspection with various scopes	Sharp dissection of tumor from normal pituitary, start at lower part of tumor	Harvesting nasal septal flap, wide sellar opening, inspection with various scopes for residual and CSF leaks
Postoperative
Admission	Floor	Intermediate care	ICU	ICU or floor
Postoperative complications feared	HPA dysfunction (adrenal insufficiency, diabetes insipidus, SIADH), CSF leak	Hyponatremia, CSF leak	CSF leak, diabetes insipidus	CSF leak, vision loss, hypopituitarism, adrenal insufficiency, diabetes insipidus
Follow-up testing	Daily BMP, daily 8 a.m. cortisols until nadir established, LD for 3 days MRI 3 months after surgery	Continue hydrocortisone for 3 months with endocrinology tapering, endocrinology testing 3 months after surgery MRI 24 hours after surgery	Cortisol and endocrine labs 2, 4, and 6 weeks after surgery MRI 2 months after surgery	Cortisol every 6 hours until less than 2 for 2–3 days after surgery MRI 3 months after surgery
Follow-up visits	1 week after surgery for neuroendocrinology 2 weeks after surgery for ENT 6 weeks after surgery for neurosurgery	3 months after surgery for neurosurgery Continual follow-up with ENT 3 months after surgery for endocrinology	2 months after surgery with neurosurgery 2 weeks after surgery with endocrinology	10 days, 6 weeks, 3 months, and annually after surgery
Adjuvant treatment for lack of biochemical cure	Little or no biochemical response: possible resection or partial/total hypophysectomy Partial biochemical response: observation for 3 months, then SRS, and then bilateral adrenalectomy	No cure: repeat surgery if visible tumor seen and accessible; medical or radiation if no visible tumor seen or residual tumor is inaccessible	No cure: repeat surgery if lesion evident on scans or radiation if no lesion apparent	SRS or medical management