Endoscopic biopsies of lesions associated with a thickened pituitary stalk

Lesions associated with a thickened pituitary stalk (TPS lesions) revealed by magnetic resonance imaging have a diverse pathology. Accordingly, for clinical decision-making, it is necessary to make a diagnosis based on histopathological examination of the TPS lesions. The objectives of this study were to review endoscopic biopsies of TPS lesions and to assess the surgical strategy for treating these lesions. Eleven patients (four males and seven females) aged from 6 to 75 years underwent endoscopic biopsy of a TPS lesion between 2006 and 2011 at University of Niigata. The relationships of the extent of lesions with surgical approaches were retrospectively examined. Among the 11 patients, a biopsy was performed via an endoscopic transsphenoidal approach for five with intrasellar lesions; via an endoscopic extended transsphenoidal approach for two with localized TPS lesions; and via an endoscopic intraventricular approach for four with the lesion protruding from the infundibulum. Histopathological examinations of all the lesions confirmed diagnoses of germinoma in four patients, hypophysitis in three, Langerhans cell histiocytosis in two, craniopharyngioma in one, and cancer metastasis in one. None of the 11 patients had further deterioration of pituitary function postoperatively. Endoscopic biopsy of TPS lesions is a less invasive alternative to open biopsy requiring transcranial surgery. The endoscopic transsphenoidal approach is most suitable for biopsies of TPS lesions associated with intrasellar lesions. Otherwise, the endoscopic intraventricular approach seems reasonable for intraventricular lesions protruding from the infundibulum, and the endoscopic extended transsphenoidal approach appears appropriate for localized TPS lesions.