The reliability of the specimens for neuropathological evaluation in pituitary adenomas treated via transphenoidal route

Introduction: There are some discrepancies between immunohistochemical staining results and clinical picture of pituitary adenomas. Such a discordance may be caused by multiple factors. The problem of securing the histopathological material during the transsphenoidal pituitary surgery and its reliability for neuropathological evaluation deserves a special attention. The surgical biopsy does not always meet the criteria required for a immunohistochemical staining and sometimes not even for the routine histopatho-logical examination. Aims: To determine the frequency of unreliable material for histopathological examination and factors influencing the reliability of histopathological specimens after surgery for pituitary adenomas. Material and methods: The hematoxylin and eosin sections were examined in detail. with a special attention to the presence of incidental findings, i.e. admixture of normal pituitary gland tissue, signs of hemorrhage, necrosis, thermal artifacts, inflammatory changes, respiratory epithelium, vessels or cholesterol granuloma. The impact of incidental findings on further immunohistochemical analysis was investigated. The relationship between the magnetic resonance imaging (MRI)- determined tumor size and the area of histopathological specimen was assessed and considered as a reliability parameter. Results: The unreliable material was estimated at the level of 11.8%. It was assessed that hemorrhages, neurohypophysis, necrosis and quantity of collected histopathological material had the statistically sig-nificant impact on the reliability of the histopathological material. The statistical analysis did not show any relation between the reliability of the histopathological material and the MRI-determined volume of the tumor. Conclusions: The presence of some additional tissue elements and artifacts in the histopathological specimen makes the immunohistochemical evaluation difficult or even impossible. However, this problem is related to a relatively low percentage of cases, mainly small tumors.