Endoscopic Surgical Characteristics of Clinically Nonfunctioning Pituitary Neuroendocrine Tumors: Comparison of TPIT-Lineage and SF1-Lineage Tumors.

OBJECTIVE: Clinically nonfunctioning pituitary neuroendocrine tumors (PitNETs) may exhibit lineage-specific radiological and intraoperative features. This study compared the radiological and intraoperative characteristics of T-box pituitary transcription factor (TPIT)-lineage and steroidogenic factor 1 (SF1)-lineage tumors. METHODS: Transcription factor immunohistochemistry was used to classify 164 clinically nonfunctioning PitNETs, consisting of 46 TPIT-lineage tumors and 118 SF1-lineage tumors. Clinical variables, preoperative neuroradiological findings including multiple microcysts, as well as intraoperative findings including tumor color, consistency, and invasiveness, were evaluated. RESULTS: The TPIT-lineage group showed a higher proportion of female patients and a higher frequency of Knosp high-grade tumors than the SF1-lineage group. Magnetic resonance imaging demonstrated that high signal intensity on T2-weighted images and multiple microcysts were more frequently observed in the TPIT-lineage group. Intraoperative findings showed that the TPIT-lineage group more frequently exhibited cavernous sinus invasion, soft aspiratable (SA)-type consistency, dark-red color, sellar dural defects, and sphenoid sinus extension (with local bone defect). Multivariable logistic regression analysis found that female sex, presence of multiple microcysts, and SA-type tumor consistency were independently associated with the TPIT-lineage group. CONCLUSIONS: Clinically nonfunctioning TPIT-lineage PitNETs, which correspond to silent corticotroph PitNETs, are characterized by radiological and intraoperative features that are readily identifiable. Although TPIT-lineage tumors may show locally invasive growth and frequently lack a distinct pseudocapsule, their soft consistency may facilitate aspiration-assisted endoscopic resection.