NCOG-31. GIANT PITUITARY ADENOMA (GPA) SCORE: A NOVEL SCORING SYSTEM TO PREDICT POSTOPERATIVE OUTCOMES OF GIANT PITUITARY ADENOMAS

BACKGROUND Giant pituitary adenomas (GPA) are uncommon and highly variable in morphology and extension. There is no scoring system that considers all the dimensions of adenoma invasion. We developed a new Giant Pituitary Adenoma score and report our surgical experience and evaluate outcomes after resection of these tumors in accordance with the preoperative score. METHODS We developed a novel scoring system for classifying giant pituitary adenomas, and 11-year data of GPA surgery at our center was collected retrospectively, based on this scoring system. GPA Score considered tumor’s parasellar extension, encasement of cavernous internal carotid artery (ICA), suprasellar extension > 2 cm, suprasellar extension > 4cm and retrosellar extension. Maximum possible score was 9. The scoring system was applied to 53 patients of GPA who underwent surgical resection between January 1, 2006, and December 2017. The Lundin-Pederson (ABC/2) method was used to calculate the tumor volume both pre- and post-resection and linear regression was used to assess the relationship between extent of tumor resection and GPA score. RESULTS The median age of the study population was 42.08 ± 16.49 years. The mean maximum diameter of the pituitary adenomas was 5.0 cm (range 4.0 cm-8.5cm) while the mean volume of the adenomas was 27.3 cm3 (range 10 cm3-149 cm3). There were 3 cases of score 2, 5 cases of score 3, 13 cases of score 4, 20 cases of score 5, 9 cases of score 6 and 3 cases of score 7. The range of tumor volumes of tumors for scores from 2-7 was 17.3 cm3 to 65.8 cm3 and GPA score was correlated with the percent residual tumor using linear regression that was statistically significant (p= 0.001). CONCLUSION GPA Score is a reliable scoring system to predict the extent and subsequent difficulty in tumor resection in GPA.

Evaluation of Pure Endoscopic Endonasal Approach in Management of Giant Pituitary Adenoma

Background Giant pituitary adenoma represents one of the challenging tumor for neurosurgeons. Many microsurgical approaches in the past were used for its management. Recently and with evolution of the endoscopic equipment and instruments, extended endoscopic transsphenoidal approach become one of the preferable approaches for its surgical excision. Methods We prospectively document the clinical , surgical and follow up data for all patients presented with giant pituitary adenoma to Ain-Shams university hospital and Weill Cornell Medical College, Presbyterian hospital and were surgically treated with extended transsphenoidal approach from 2015 till 2019. Results Our group study formed of 44 patients with mean age 53.03 (range 14.7-82.4) and a male predominance (59%). The main presentation was visual problems in 75% followed by partial hypopituitarism in 31.81% while headache was in 13.64%. Only 4 patients had functioning adenoma (3 prolactinoma and 1 acromegaly). Average tumor volume was 26.95 ± 17.25 cm3, while the mean maximum tumor diameter was 4.73 cm (range 4.0-8.0 cm). Radiographic invasion was found in 97.73% to suprasellar cistern, 61.36% to the cavernous sinus and in 34% to the sphenoid sinus. GTR was achieved in 45.45% with Knosp score is the only significant predictor factor for resection rate (p = 0.04). Visual improvement achieved in 75.76%. 50% (2 patient) of the patients with functioning adenoma were cured. Complications included CSF leak in 3 patients, permanent DI in 4 patients and postoperative hematoma in 2 patients. Recurrence and progression rates without upfront radiation therapy were 5.00 % and 31.81% respectively after mean follow up period 57.90 months. Conclusions Extended endoscopic approaches for achieving maximum resection with minimal morbidity for giant pituitary adenoma are very effective. Lateral tumor extension with cavernous sinus invasion represents the limiting point in achieving gross total resection. Upfront radiation therapy for patients with residual adenoma can be avoided but regular follow up should be warranted.

Endoscopic approach for giant pituitary adenoma: clinical outcomes of 205 patients and comparison of two proposed classification systems for preoperative prediction of extent of resection

OBJECTIVE Giant pituitary adenoma is considered a challenging pathology for surgery owing to its complications and low resection rate. In this study, the authors present their experience of using the endoscopic endonasal approach to treat patients with giant pituitary adenoma, and they aimed to develop a classification system for prediction of extent of resection. METHODS The institutional medical records of patients diagnosed with giant pituitary adenoma who underwent endoscopic endonasal transsphenoidal surgery between August 1997 and December 2019 were retrospectively reviewed. Surgical and clinical outcomes were evaluated in detail. The effects of tumor characteristics on extent of resection were analyzed. The findings were used to develop two classification systems that could preoperatively predict extent of resection. Morphological score was based on tumor characteristics, and landmark-based classification was defined according to surgical zones based on neurovascular landmarks. The effects of change in surgical strategy, which aimed to maximize tumor resection and capsule dissection, on rates of resection and complications were evaluated before and after 2017. RESULTS This study included 205 patients, with a mean patient age of 46.95 years and mean preoperative tumor diameter of 46.56 mm. Gross-total resection (GTR) was achieved in 35.12% of patients, near-total resection (NTR) in 39.51%, and subtotal resection (STR) in 25.36%. Extent of resection differed significantly between the grades and zones of the classification systems (p < 0.001 for both). Among patients with grade 3 tumor, 75.75% of patients achieved STR, 21.21% achieved NTR, and 3.03% achieved GTR. Among patients with zone 3 tumor, 65.75% achieved STR, 32.87% achieved NTR, and 1.36% achieved GTR. Both grade 3 and zone 3 indicated limited extent of resection. The mean (range) follow-up duration was 50.16 (9–247) months. Postoperative recovery of at least one hormone axis was seen in 15.24% of patients with pituitary deficiency, and development of new hormonal deficiency was observed in 22.43% of patients. Complications included permanent diabetes insipidus (7.80%), cerebrospinal fluid leakage (3.90%), postoperative apoplexy (3.90%), meningitis (3.41%), and epistaxis (3.41%). The surgical mortality rate was 1.46%. Among 85 patients treated before 2017, 27.05% of patients achieved GTR, 37.64% achieved NTR, and 35.29% achieved STR; among 120 patients treated after 2017, 40.83% achieved GTR, 40.83% achieved NTR, and 18.33% achieved STR. Seven patients in the pre-2017 cohort had postoperative apoplexy versus only 1 patient in the post-2017 cohort. There were no statistically significant differences between the two periods in terms of the incidence rates of other complications. CONCLUSIONS Capsule dissection and GTR are valuable for preventing serious complications and reducing recurrence of giant adenoma. Treatment of giant pituitary adenoma may be better managed with the help of a classification system that provides information about extent of resection that can be achieved with an endoscopic approach.

Ruptured aneurysm–induced pituitary apoplexy: illustrative case

BACKGROUND Pituitary apoplexy associated with aneurysmal rupture is extremely rare and may be misdiagnosed as primary pituitary adenoma apoplexy. The authors present a case of a patient with pituitary apoplexy caused by rupture of an anterior cerebral artery aneurysm embedded within a giant pituitary adenoma, and they review the relevant literature. OBSERVATIONS A 78-year-old man experienced sudden headache with progressive vision loss. Magnetic resonance imaging (MRI) revealed a giant pituitary tumor with abnormal signal intensity. Magnetic resonance angiography immediately before surgery showed a right A1 segment aneurysm, suggesting coexisting pituitary apoplexy and ruptured aneurysm. The patient underwent urgent transsphenoidal surgery for pituitary apoplexy. The tumor was partially removed, but the perianeurysmal component was left behind. Subsequent cerebral angiography showed a 5-mm right A1 aneurysm with a bleb that was successfully embolized with coils. Retrospective review of preoperative dynamic MRI showed extravasation of contrast medium from the ruptured aneurysm into the pituitary adenoma. Histopathologic examination showed gonadotroph adenoma with hemorrhagic necrosis. Postoperatively, the patient’s visual function improved. LESSONS MRI identification of pituitary apoplexy caused by aneurysmal rupture has not been reported previously. Aneurysmal rupture should be considered in the differential diagnosis of pituitary apoplexy. When a ruptured aneurysm is encountered, the authors recommend treating it before addressing pituitary apoplexy.

Giant Pituitary Adenoma Presenting With Disinhibition: A Case Report of a 25-Year-Old Male

Background: Giant growth hormone secreting pituitary adenomas (defined by a diameter &gt;4cm) are rare and difficult to treat (1). These typically invade surrounding structures, making surgery challenging or impossible (1). This report highlights a giant mammosomatotrophinoma with an unusual clinical presentation. Clinical Case: A 25-year-old male presented with personality changes, disinhibition and executive dysfunction progressing over a 3 to 4-year period. Further enquiry elicited a history of increasing headaches and significant visual loss, on the background of unilateral childhood visual loss in the contralateral eye. He was noted to have clinical features of acromegaly and complete temporal visual field loss in the left eye. On initial testing plasma IGF-1 was 137 nmol/L (reference interval [RI] 13-43nmol/L), GH &gt;100 ug/L and prolactin 23,900 mIU/L (RI 0-400mIU/L). GH remained &gt;100ug/L at 120 minutes after a 75g oral glucose load. He has hypogonadotropic hypogonadism, however thyrotropic and corticotropic function remained normal. MRI of the brain with contrast revealed an 8.0 x 7.1 x 7.4 cm mass arising from the pituitary fossa, extending into the suprasellar region and displacing both frontal lobes. The mass encased the basilar and right internal carotid arteries. It was deemed inoperable due to its exceptionally large size and encasement of vascular structures. Medical treatment was initiated with cabergoline (3.5mg per week in divided doses) and octreotide LAR, initially 30mg then increased to 60mg 4-weekly. A weaning course of steroids was initiated for oedema of his optic nerve. Within one month of treatment there was improvement of clinical symptoms of headaches, sweating, irritable mood and disinhibition with associated modest biochemical improvement (reduction of IGF-1 to 129 nmol/L and prolactin reduction to 2119 mIU/L). MRI of the brain revealed a reduction in the size of the adenoma to 7.8 x 7.1 x 6.3 cm, with a reduction in the mass effect on the frontal lobes. The patient continues medical management and close clinical monitoring with the aim of ongoing tumour shrinkage to allow reassessment for possible surgical debulking. Conclusion: This unique case of a GH and prolactin co-secreting giant pituitary adenoma posed a therapeutic challenge due to the significant surgical risk, limiting treatment to aggressive medical therapy. The cognitive and behavioral changes experienced due to tumour size and location added to the management complexity. Although early on in the treatment course, there is improvement of symptoms and tumour size on cabergoline and octreotide LAR injections. (1) Iglesias P, Rodríguez Berrocal V, Díez JJ. Giant pituitary adenoma: histological types, clinical features and therapeutic approaches. Endocrine. 2018 Sep;61(3):407-421.