Muhammad Husain, Robert L. Archer, and Fred Faas Departments of Ophthalmology (M.S.V.), Neurology (M.S.V., R.L.A.), Neurosurgery (A.K.), Pathology (M.H.), and Endocrinology (F.F.) University of Arkansas for Medical Sciences Little Rock, Arkansas 72205-7199
We enjoyed the manuscript by Pluta et al. (1) entitled "Extrapituitary Parasellar Microadenoma in Cushings Disease." We were impressed by the rarity of ACTH ectopic pituitary adenomas occupying the cavernous sinus. Pluta et al. (1) have reported the first three cases of this type in the literature. We have a similar patient with an ectopic pituitary adenoma of the cavernous sinus, however, our patient also had pituitary apoplexy. She is a 43-yr-old woman who experienced the worst headache of her life, diplopia, ptosis, and proptosis of her right eye. She has a history of Cushings syndrome, diagnosed in 1991. She had multiple 24-h urine free cortisol levels that were substantially elevated, ranging from 185374 µg/24 h (20100 µg/24 h). There was no evidence of suppression with dexamethasone, and plasma adrenocorticotropic hormone levels were high normal at 77 and 73 pg/mL (<80 pg/mL). Urinary 17-hydroxycorticoid levels were, likewise, elevated ranging between 23 and 59 mg/24 h (210 mg/24 h) as were plasma cortisol levels of 43 and 35 µg/dL (316 µg/dL). A magnetic resonance imaging scan of the brain revealed a small mass in the region of the superior aspect of the right cavernous sinus and posterior aspect of the sella. A transsphenoidal subtotal hypophysectomy was performed on March 25, 1992. There was no pathologic evidence of pituitary adenoma, only normal pituitary tissue. After surgery, she had persistent evidence of Cushings syndrome and she subsequently developed hypothyroidism. She was treated medically with aminoglutethimide.
The neuro-ophthalmologic examination revealed an alert, oriented woman who appeared acutely ill. She was supine in bed and would not sit up because it worsened her headache. Her visual acuity at near with correction was J5 OD (right eye), no help with additional spheres and J1 OS (left eye). Color vision was 6.5 of 14 OD, 8 of 14 OS using Ishihara pseudo-isochromatic plates, and confrontational visual fields were full OU (both eyes). Pupils were 8 mm in diameter OD and fixed, 4 mm OS with normal reactivity, and there was a small relative afferent pupillary defect OS (felt to be due to the inter-eye luminance disparity from the dilated fixed pupil OD). There was a complete ophthalmoplegia OD, ductions were full OS. The palpebral fissures measured 3 mm OD, 8 mm OS. Exophthalmometry readings of 30 mm OD and 27 mm OS were noted with a base of 113 mm. Testing of the trigeminal nerve (including corneal reflexes) and facial nerves were intact bilaterally. Slit lamp examination was normal, and intraocular pressures of 23 mm Hg OD and 25 mm Hg OS were noted. Ophthalmoscopy revealed a normal-appearing optic nerve and fundus OU.
Investigation of the patient included an enhanced magnetic resonance imaging of the brain, which showed a 1.4 x 2-cm nonenhancing lesion in the right cavernous sinus, and laboratory testing showed that serum cortisol was 58 µg/dL (316 µg/dL).
Dexamethasone was instituted, and an extradural cranial surgical approach to the right cavernous sinus was performed. The pathologic specimen revealed hemorrhagic and necrotic tissue with spared islands and rims of cellular clumps and columns of monomorphous tumor cells. The immunohistochemical stains showed positive staining for adrenocorticotropic hormone and, to a lesser extent, GH. The other immunohistochemical hormonal stains were negative. Postoperative serum and urine cortisol levels were low or undetectable, indicating biochemical cure of her Cushings disease. The patient was maintained on hydrocortisone, and in September 1998 her neuro-ophthalmological examination had normalized.
Pituitary adenomas constitute 1012% of all brain neoplasms, and they rarely occur in ectopic sites. Reported locations of ectopic pituitary adenomas include the sphenoid sinus (most common) (2), clivus (3), sphenoid wing (4), petrous temporal bone, temporal lobe and superior orbital fissure (5), pituitary stalk (6), hypothalamic region (7), third ventricle (8), diaphragma sellae (9), interpeduncular cistern (10), suprasellar areas (5), and cavernous sinus (1). Apoplexy is a rare event in nonectopic pituitary tumors, occurring in approximately 10% of patients (11). In our patient, her Cushings disease was probably related to the tumor that was not detectable on earlier neuroimaging studies.
During neurosurgery, the tumor was very well compartmentalized within the cavernous sinus. Whether this compartmentalization prevented it from further growth and enhanced the occurrence of the apoplectic event is a matter of speculation.
There is only one case of an ectopic pituitary adenoma that underwent apoplexy reported in the literature (12). To our knowledge, our patient is the only reported case of an ectopic pituitary adenoma arising in the cavernous sinus that underwent apoplexy (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12).
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