6566 Concurrent Papillary Craniopharyngioma and Growth Hormone-Secreting Pituitary Adenoma: A Rare Collision Tumor

Abstract Disclosure: A.J. Mancini: None. R. Mathew: None. J. Oentoro: None. A.M. Devine: None. C. Maxwell: None. I. Kravets: None. Introduction: Collision tumors, which consist of two or more histologically distinct tumors in the same anatomic location, are rare; when occurring in the sella, they more commonly consist of a pituitary adenoma and Rathke cleft cyst. Here, we present a case of a collision tumor consisting of a papillary craniopharyngioma and GH-secreting pituitary adenoma. Clinical Case: A 49-year-old man presented with two months of headaches and blurry vision. Physical exam showed frontal bossing, enlarged jaw and hands, and macroglossia. A visual field exam revealed bitemporal hemianopsia. Initial labs included PRL 105.2 ng/mL (4.0-15.2), TSH 0.399 uIU/mL (0.27-4.2), free T4 0.95 ng/dL (0.93-1.70), FSH 0.8 mIU/mL (1.5-12.4), LH 0.3 mIU/mL (1.7-8.6), total testosterone 10 ng/dL (300-890) drawn at 6:00 a.m., cortisol 8.5 ug/dL (6.0-18.4) and ACTH 32.1 pg/mL (7.2-63.3) drawn at 10:30 a.m.; an IGF-1 was not initially sent. Pituitary MRI showed a 4.1 cm mixed solid and cystic sellar/suprasellar mass with mass effect on the optic chiasm. The patient underwent a craniotomy with tumor resection on hospital day (HD) 5 with pathology showing a papillary craniopharyngioma. The next week, an elevated IGF-1 level of 517 ng/mL (68-225) prompted a GH suppression test. GH levels 1 and 2 hours after oral glucose load were 19.3 ng/mL (0.05-3.00) and 17.8 ng/mL respectively, confirming the diagnosis of acromegaly. On HD 20, repeat MRI showed an interval increase in the mass size with increased mass effect on the optic chiasm. A second craniotomy with an endoscopic resection of the mass was performed, with pathology again showing a papillary craniopharyngioma. Post-operative MRI showed a residual mass with mild mass effect on the optic chiasm for which the patient began radiation therapy. Interval MRI demonstrating a further increase in the tumor size plus a rising IGF-1 level of 700 ng/mL and ongoing lack of GH suppression with an oral glucose load prompted a transsphenoidal resection of the tumor on HD 54. The pathology showed a growing residual papillary craniopharyngioma and a component of a PIT1 lineage adenoma, the majority of which expressed GH. The patient developed numerous complications during his hospitalization and ultimately passed away on HD 64. Conclusion: There are 22 reported cases of collision tumors of pituitary adenomas and craniopharyngiomas, and only five secreted GH. Moreover, four of the five cases described collision tumors with an adamantinomatous craniopharyngioma; the fifth case did not include data on the type of craniopharyngioma (1). Therefore, to the best of our knowledge, our case represents the first collision tumor of a GH-secreting pituitary adenoma and papillary craniopharyngioma. Reference: (1) Hasegawa H, Jentoft ME, Young WF, et al. Collision of Craniopharyngioma and Pituitary Adenoma: Comprehensive Review of an Extremely Rare Sellar Condition. World Neurosurg. 2021;149:e51-e62. Presentation: 6/3/2024