Abstract

Background: Pituicytoma is a rare low-grade glioma of the sellar and suprasellar region, arising from pituicytes of the posterior pituitary and infundibulum, with only a limited number of cases reported in the literature. Due to the lack of specific radiological features and significant histomorphologic overlap with other sellar lesions, preoperative diagnosis remains challenging. It is often misdiagnosed as more common entities such as pituitary neuroendocrine tumors, meningioma or pilocytic astrocytoma. Immunohistochemistry plays a crucial role in establishing the correct diagnosis. Case Presentation: We report a 66-year-old male patient who was initially diagnosed with pituitary adenoma. Magnetic resonance imaging of the brain identified a well-defined 2 × 1.6 cm, arising from the sellar and suprasellar regions, compressing optic chiasma. The patient underwent surgical resection. Following surgical resection, patients are clinically monitored and managed for postoperative complications. Histopathological examination, together with immunohistochemical staining showing TTF-1(+), S100(+), Chromogranin(-), Synaptophysin(-), GFAP(-), and Desmin(-), confirmed the diagnosis of Pituicytoma. Conclusion: Pituicytoma is a rare benign tumor of the posterior pituitary lobe with a limited number of reported cases, particularly in Vietnam, accompanied by nonspecific clinical and radiological findingsThis case highlights the diagnostic challenge of pituicytoma and underscores the essential role of immunohistochemistry, particularly TTF-1, in distinguishing it from other sellar tumors.