Abstract
BACKGROUND: Histiocytic sarcoma (HS) is a rare malignant tumor of histiocytic origin, both morphologically and immunohistologically. Herein, the authors report the case of a suprasellar tumor confirmed as HS after craniotomy, which presented a diagnostic challenge. OBSERVATIONS: A 58-year-old man presented with panhypopituitarism. To protect the patient's visual function and obtain a diagnosis, craniotomy was performed for tumor removal. Based on the immunohistological staining results, the tumor tested positive for both CD68 and CD163 and negative for CD1a, CD21, and MP0. Hence, the patient was diagnosed with HS. The tumor grew rapidly after surgery. Thus, the patient underwent reoperation. The patient's visual acuity and visual field deficits improved. However, he developed intractable electrolyte abnormalities caused by hypothalamic damage. Then, he exhibited intractable seizures and pneumonia and died 4 months after surgery. LESSONS: This report emphasizes the rarity of suprasellar HS and its associated challenges in diagnosis and surgical treatment. https://thejns.org/doi/10.3171/CASE24297.