Case report: Spindle cell sarcoma and pituitary adenoma in the sella region-a rare collision tumor.

Background: Collision tumors are defined as two or more distinctly bordered, mutually invasive tumors in the same anatomical region. Characterized by low incidence and lack of specificity, they often pose a significant challenge to disease diagnosis. Among these, collision tumors in the sella region are incredibly rare. Case description: On 13 June 2023, the Department of Neurosurgery at Drum Tower Hospital admitted a patient with a pituitary adenoma in the sella region complicated by spindle cell sarcoma. After reviewing the literature, no related cases were reported. A patient presenting with complex clinical symptoms and preoperative imaging showing occupancy in the sella region is considered to have a recurrence of pituitary adenoma. After thorough preoperative evaluation and discussion, a trans-sphenoidal approach (with the aid of an endoscope) was performed to resect the pituitary lesions. Combined with postoperative pathological tissue and imaging, the patient was diagnosed with a pituitary adenoma (postoperative recurrence) in the sella region complicated by spindle cell sarcoma. The patient made a fair recovery and was discharged on the 8th postoperative day. Conclusion: This case report aims to elucidate and discuss the diagnosis and screening of rare collision tumors in the sella region to reduce the misdiagnosis rate and provide accurate treatment.