Abstract Disclosure: S. Avula: None. A. Ahmed: None. M. Salim: None. H. Alameddine: None. Introduction: Metastasis to pituitary is very rare occurrence, accounting for 1-4%. Most common primary cancer that metastasis to pituitary are Breast cancer in females and Lung cancer in males. Most of the pituitary metastasis are asymptomatic with symptomatic patient account for around 7 %. Most common symptoms reported are anterior pituitary dysfunction, visual field defects, headache, diabetes insipidus. Metastasis from Renal cell carcinoma (RCC) is very rare with only 25 cases reported so far. Metastases to the pituitary from RCC cause more severe hypopituitarism and visual dysfunction in comparison to those from other primaries. We present a rare case of hypopituitarism due to metastatic RCC presenting after Clinical Case: A 59-year-old male who initially presented in 2010 with complains of abdominal pain, underwent abdominal imaging and was found to have 7 cm solid mass in the right kidney. He underwent right nephrectomy in France and pathology confirmed RCC with no lymph node involvement. Patient didn’t have any adjuvant therapy. He had 5 years of follow up surveillance scans in Palestine which didn’t show any recurrence. In 2021 patient started to notice vision changes with loss of peripheral vision loss on right side but he didn’t seek any medical attention. In 9/2022 he noticed to have excessive fatigue, low libido, low appetite, excessive thirst and worsening of his vision. He had hormonal evaluation done in Palestine which showed low testosterone, cortisol, thyroid levels and was diagnosed with panhypopituitarism and was started on Hydrocortisone, Levothyroxine, Testosterone and Desmopressin. In 9/2022 had MRI brain in Palestine and showed 2cms suprasellar enhancing mass arising in the suprasellar cistern and appears inseparable from the pituitary stalk infundibulum. In 11/2022 he came to USA for further evaluation and management. In November 2022 patient complained of hallucinations, memory loss, personality changes and bitemporal vision loss. MRI brain showed sellar and suprasellar mass, 2.1 x 2.3 x 3.8 cm, extending to the suprasellar cistern and elevates the optic chiasm with possible third ventricle involvement and had increased in size compared to previous scan. On 11/29/22 patient underwent Endoscopic Endonasal Transplanum, Transtuberculum approach for tumor removal, biopsy of sellar and suprasellar tumor which returned as metastatic RCC. Patient was discussed in tumor board and is scheduled for gamma knife. Conclusion: Metastatic RCC to pituitary is very rare and most of them are asymptomatic leading to delay in diagnosis. Treatment of pituitary metastases is not standardized and should be tailored to patients’ clinical conditions, histology, and presence of extra-pituitary metastases. We need more prospective studies to formulate guidelines for management of pituitary metastases. Presentation: Thursday, June 15, 2023