## 3 Results  
The series includes 75 patients (41, 54.6%) were male, age: 55.9 \(\pm\) 16). As reported in Table 1, the majority were non-functioning tumors (58, 77.3%), followed by 9 (12%) PRL tumors, 6 (8%) GH-secreting tumors, and 2 (2.7%) ACTH-secreting ones. Most of the cases were naive (72, 96%) and 3 cases (4%) have undergone previous endoscopic endonasal subtotal resection (in all cases, the second surgery was needed for the progression of the remnant). At pre-operative bio-humoral assays, 36 (48%) patients presented a normal pituitary function. In the remaining patients, anterior hypoptiuitarism was present in 26 (34.7%) cases and isolated Diabetes Inspidus (DI) was evident in 1 (1.3%), already operated on in the past. Acromegaly, i.e., hyper-secretion of GH and insulin-like growth factor 1 (IGF-1), was demonstrated in 6 cases (8%), while a central Cushing disease was confirmed in 2 (2.7%). For elevated levels of serum prolactin (\(>\)200 ng/mL) in tumors not responding to \begin{table}
\begin{tabular}{c c c c} \hline \hline  & & **No. of Patients** & **\%** \\ \hline Previous Treatment & none & 72 & 96\% \\  & surgery & 3 & 4\% \\  & radiotherapy & 0 & 0\% \\ \hline Tumor & GH-secreting tumors & 6 & 8\% \\  & PRL-secreting tumors & 9 & 12\% \\  & ACTH-secreting tumors & 2 & 2.7\% \\  & Non-functioning tumors & 58 & 77.3\% \\ \hline Endocrine Functions & none & 36 & 48\% \\  & anterior hypoptiuitarism & 26 & 34.7\% \\  & Diabetes Inspidus (DI) & 1 & 1.3\% \\  & Acromegaly & 6 & 8\% \\  & Cushing disease & 2 & 2.7\% \\  & HyperPRL (\(>\)200 ng/mL) & 9 & 12\% \\ \hline Visual Symptoms & no & 35 & 46.7\% \\  & present & 40 & 53.3\% \\ \hline Ophthalmoplegia & no & 69 & 92\% \\  & present & 6 & 8\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Patients’ pre-operative features. GH = growth hormone; PRL = prolactin; ACTH = adrenocortic hormone. cabergoline treatments, the diagnosis of resistant prolactinoma was suspected in 9 cases (12%). As reported in Table 1, visual disturbances were present pre-operatively in 40 (53.3%) cases, while 6 (8%) patients presented ophthalmoplegia, due to pituitary apoplexy. As shown in Table 2, most of the tumors were classified as grade 2 according to the [PERSON] scale (43, 57.3%) and as A or B according to Wilson (respectively, 33 (44%) and 30 (40%)). No CS invasion was suspected in 26 (34.7%) patients (Knosp grade 0), 28 (37.3%) patients presented a low Knosp grade (1 or 2), and 21 (28%) a high grade (3 or 4). The mean maximum horizontal diameter (HD) of the tumor was 23.9 \(\pm\) 6.3 mm and the mean minimal inter-carotid distance (ICD) was 23.2 \(\pm\) 3.9 mm; therefore, in the Zurich Pituitary Score system, most of our series were grade 2 (59, 74.7%). According to our proposed 3D characterization of the tumor, the mean Vol was 9117 \(\pm\) 8423 mm\({}^{3}\), mean Area was 2352 \(\pm\) 1571 mm\({}^{2}\), mean Spher was 0.86 \(\pm\) 0.08, and mean Conv was 0.88 \(\pm\) 0.08 (Table 3). Total tumor removal was achieved in 57 (75%) cases, subtotal in 15 (20%), partial in 1 (1.3%), and incomplete in 2 (2.7%) (Table 3). Surgical complications consisted of 2 (2.7%) post-operative cerebrospinal fluid (CSF) leaks, that have been promptly repaired to avoid meningitis. Other complications were 1 (1.7%) subarachnoid hemorrhage and 1 (1.7%) surgical field hematoma, which were treated conservatively with the patient's favorable outcome, and 1 (1.7%) transient CN III palsy, which recovered spontaneously after 3 months. Biochemical remission of hyper-secretion was observed in 2 GH adenomas, 5 PRL adenomas, and 1 ACTH adenoma. All patients not presenting a post-operative remission of hyper-secretion started medical therapy, obtaining control of the disease in all cases. At statistical analysis, the logistic regression demonstrated that Knosp grade and two indexes referring to 3D characterization (i.e., Vol and Conv) were independent significant predictors of the extent of tumor resection (Table 4).