Development and clinical validation of a grading system for pituitary adenoma consistency

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Pituitary adenoma (PA) consistency, or texture, is an important intraoperative characteristic that may dictate operative dissection techniques and/or instruments used for tumor removal during endoscopic endonasal approaches (EEAs). The impact of PA consistency on surgical outcomes has yet to be elucidated.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>The authors developed an objective 5-point grading scale for PA consistency based on intraoperative characteristics, including ease of tumor debulking, manipulation, and instrument selection, ranging from cystic/hemorrhagic tumors (grade 1) to calcified tumors (grade 5). The proposed grading system was prospectively assessed in 306 consecutive patients who underwent an EEA for PAs, and who were subsequently analyzed for associations with surgical outcomes, including extent of resection (EOR) and complication profiles.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>Institutional database review identified 306 patients who underwent intraoperative assessment of PA consistency, of which 96% were macroadenomas, 70% had suprasellar extension, and 44% had cavernous sinus invasion (CSI). There were 214 (69.9%) nonfunctional PAs and 92 functional PAs (31.1%). Distribution of scores included 15 grade 1 tumors (4.9%), 112 grade 2 tumors (36.6%), 125 grade 3 tumors (40.8%), 52 grade 4 tumors (17%), and 2 grade 5 tumors (0.7%). Compared to grade 1/2 and grade 3 PAs, grade 4/5 PAs were significantly larger (22.5 vs 26.6 vs 27.4 mm, p &lt; 0.01), more likely to exhibit CSI (39% vs 42% vs 59%, p &lt; 0.05), and trended toward nonfunctionality (67% vs 68% vs 82%, p = 0.086). Although there was no association between PA consistency and preoperative headaches or visual dysfunction, grade 4/5 PAs trended toward preoperative (p = 0.058) and postoperative panhypopituitarism (p = 0.066). Patients with preoperative visual dysfunction experienced greater improvement if they had a grade 1/2 PA (p &lt; 0.05). Intraoperative CSF leaks were noted in 32% of cases and were more common with higher-consistency-grade tumors (p = 0.048), although this difference did not translate to postoperative CSF leaks. Gross-total resection (%) was more likely with lower PA consistency score as follows: grade 1/2 (60%), grade 3 (50%), grade 4/5 (44%; p = 0.045). Extracapsular techniques were almost exclusively performed in grade 4/5 PAs. Assignment of scores showed low variance and high reproducibility, with an intraclass correlation coefficient of 0.905 (95% CI 0.815–0.958), indicating excellent interrater reliability.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>These findings demonstrate clinical validity of the proposed intraoperative grading scale with respect to PA subtype, neuroimaging features, EOR, and endocrine complications. Future studies will assess the relation of PA consistency to preoperative MRI findings to accurately predict consistency, thereby allowing the surgeon to tailor the exposure and prepare for varying resection strategies.</jats:p></jats:sec>

Presurgical somatostatin receptor ligand treatment does not affect tumor consistency in GH-secreting pituitary macroadenomas

“…Our results are supported by previous studies, finding similar surgical results in soft an fibrous tumors [13] or even some authors [29] suggesting that the firm capsule may facilitate the removal of a fibrous suprasellar adenoma. Moreover, other authors have previously described that PAs invading the cavernous sinuses had a higher consistency grade [26], but also a greater risk of surgical morbidity and lower chance of surgical remission in this series. In this same line, most literature agrees that treating fibrous tumors is associated with certain technical problems, including the need for twostage transsphenoidal surgery [8] [30], and thus a subsequently lower chance of total surgical resection and higher risk of complications, similarly as the observed in meningiomas [31].…”

“…The percentage of hard tumors GH-secreting macroadenomas in our series was of 27.5% (11 out of 40), and of very hard of 7.5% (3 out of 40). This prevalence is slightly higher that the generally considered in most series, to be between 5 and 13.5% [24][25][26], or even some studies reported prevalence of 0% in this type of functioning-PAs [27] [24]. In general, functional tumors were of softer consistency than non-functional PAs [26].…”

“…This prevalence is slightly higher that the generally considered in most series, to be between 5 and 13.5% [24][25][26], or even some studies reported prevalence of 0% in this type of functioning-PAs [27] [24]. In general, functional tumors were of softer consistency than non-functional PAs [26]. These differences in prevalence are probably related to the wide range of definitions used, since most definitions are based on intraoperative findings.…”

“…These differences in prevalence are probably related to the wide range of definitions used, since most definitions are based on intraoperative findings. Therefore, classification depends on neurosurgeon criteria and varies from two grade consistence classification [24][25] to even five-grade classification [26].…”

Characteristics and clinical outcomes in pituitary incidentalomas and non-incidental pituitary tumors treated with endoscopic transsphenoidal surgery

“…In our study, although there were no differences about tumor size and the incidence of anterior pituitary hormonal deficiencies between the PI-group and non-PI group, patients in the PI-group had significantly better outcomes than those of the non-PI group. Rutkowski et al [ 20 ] developed an objective 5-point grading scale for PA consistency based on intraoperative characteristics, including ease of tumor debulking, manipulation, and instrument selection, ranging from cystic/hemorrhagic tumors (grade 1) to calcified tumors (grade 5). In the study, high-grade PAs had more preoperative and postoperative panhypopituitarism.…”