Clinicopathological correlates of extrasellar growth patterns in pituitary adenomas

Identifying prognostic predictors for postoperative pituitary neuroendocrine tumour recurrence: an integrated clinical, radiological, and immunohistochemistry assessment

OBJECTIVE

Pituitary neuroendocrine tumours (PitNETs) are the second most common type of intracranial tumour. Several studies have explored the prognostic factors for PitNETs. However, prognostic factors for postoperative PitNET recurrence remain not fully understood. This study aimed to explore potential prognostic factors for PitNET recurrence, such as surrounding tissue invasion and the extent of surgical resection in patients with postoperative PitNETs.

METHODS

We included 106 patients who underwent PitNET surgery between 2013 and 2018, dividing them into two groups: those with recurrence and those without recurrence. Tumours were classified based on demographics, neuroradiological, and immunohistological characteristics. Univariate and multivariate analyses were used to determine factors predicting recurrence. Kaplan-Meier plots and log-rank tests were used to analyse each independent factor based on the cumulative 5-year recurrence rate.

RESULTS

During the 5-year follow-up period, 29.2% of the patients (n = 31) had disease recurrence. Univariate analysis showed that predictors of recurrence included cavernous and sphenoid sinus invasions, optic chiasm compression, larger tumour volume, giant adenoma >4 cm, and gross total resection (GTR). Multivariate analysis showed that lactotroph tumour type, sphenoid sinus invasion, and GTR were independent predictors. Kaplan-Meier analysis revealed significant differences in the 5-year recurrence rate among the three independent predictors, with significantly lower recurrence rate in patients with lactotroph tumours and GTR, and a significantly higher recurrence risk in patients with sphenoid sinus invasion.

CONCLUSIONS

Lactotroph tumour type, sphenoid sinus invasion, and GTR are independent predictors of postoperative PitNET recurrence. This study provides insights into the factors affecting postoperative PitNET recurrence.

Morphological Classification of Pituitary Tumors With Suprasellar Extension

BACKGROUND AND OBJECTIVES

The objective of this study was to study the association among various morphological parameters and surgical outcomes in pituitary macroadenomas with suprasellar extension.

METHODS

MRI studies of 160 patients undergoing endoscopic transsphenoidal resection of pituitary macroadenomas with suprasellar extension were reviewed. In the coronal plane, tumors were classified into Type 1 (dome-shaped, no constriction at the level of diaphragma sellae) and Type 2 (dumbbell-shaped, with constriction at the level of diaphragma sellae). Based on the dome-to-neck ratio (D/Nr), Type 2 tumors were further classified as Type 2A (wide neck; D/Nr >1 and <1.3) and Type 2B (narrow neck; D/Nr ≥1.3). Surgical outcomes and complications were analyzed using a logistic regression model. Overall extent of resection (EOR) and presence of residual sellar-suprasellar tumor was separately assessed in all patients with available postoperative MRI (n = 149).

RESULTS

There were 108 Type 1 tumors and 26 patients each in the Type 2A and Type 2B subgroups. Tumor subtype was significantly associated with tumor size (P < .001), intraoperative cerebrospinal fluid leak (P < .001), EOR (P < .001), postoperative suprasellar residual tumor (P < .001), and postoperative complications, including diabetes insipidus (P = .005) and visual worsening (P = .003). On multivariate analysis, after adjusting for confounders, Type 2B tumors were negatively associated with EOR (odds ratio [OR] 0.22; 95% CI 0.07-0.68; P = .008) and associated with the presence of postoperative suprasellar residual tumor (OR 18.08; 95% CI 5.20-62.89; P < .001), intraoperative cerebrospinal fluid leak (OR 5.33; 95% CI 1.89-14.99; P = .002), and postoperative diabetes insipidus (OR 4.89; 95% CI 1.67-14.35; P < .001).

CONCLUSION

Preoperative tumor classification based on D/Nr is clinically and surgically relevant, and Type 2B macroadenomas are significantly associated with lower rates of gross total resection and higher rates of postoperative complications after endoscopic transsphenoidal resection.

Patterns of extrasellar invasive growth of pituitary adenomas with normal sellar cavity size

BACKGROUND

Pituitary adenomas (PAs) are among the most common brain tumors which characteristically become symptomatic due to the mass effect on surrounding structures and/or hormonal imbalances. This study describes 28 cases of PAs with an extrasellar invasive growth (EIG) at the early stage of tumor growth with normal sellar cavity size.

METHODS

1200 cases of PAs either treated medically or via Endoscopic transsphenoidal surgery were reviewed during a 10-year period. Pre-operative imaging was analyzed to evaluate the tumor expansion pattern, tumor invasion sites and other relevant tumor properties. A comprehensive preoperative endocrinological along with postoperative histopathological studies were conducted to evaluate the subjects' homeostasis and further identify the lesions characteristics.

RESULTS

Of the 28 patients, patients 19, 2, 1 and 6 had a growth hormone (GH)-secreting PA, an adrenocorticotropic hormone (ACTH)-secreting PA, a nonfunctional PA (NFPA) and a mix-hormones secreting PA, respectively. There was a statistically significant difference between patients with and without EIG regarding types of PAs (P = 0.000). Post-hoc tests demonstrated that GH-secreting PAs (P = 0.0003) and mix-hormones secreting PAs (P = 0.0000) are significantly more invasive, while NFPAs (P = 0.0000) are less invasive. There was not a statistically significant difference between the invasion sites and different types of PAs (P = 0.122).

CONCLUSION

Among different histological subtypes of PAs, GH-secreting PAs revealed a remarkable tendency for EIG with normal sellar cavity size. The extra-sellar tumor extension with a normal sella did not correlate with atypical histology. Considering EIG patterns, surgeons should be vigilant to investigate and follow the tumor spreading to its enclosing boundary during surgery, the clival part of sphenoid bone should be more exposed, and both inferomedial and lateral borders of the sphenoid sinus should be carefully explored in order to remove the tumor.

Identification of the Extradural and Intradural Extension of Pituitary Adenomas to the Suprasellar Region: Classification, Surgical Strategies, and Outcomes

Objective

Suprasellar pituitary adenomas (PAs) can be located in either extradural or intradural spaces, which impacts surgical strategies and outcomes. This study determined how to distinguish these two different types of PAs and analyzed their corresponding surgical strategies and outcomes.

Methods

We retrospectively analyzed 389 patients who underwent surgery for PAs with suprasellar extension between 2016 to 2020 at our center. PAs were classified into two main grades according to tumor topography and their relationships to the diaphragm sellae (DS) and DS-attached residual pituitary gland (PG). Grade 1 tumors were located extradurally and further divided into grades 1a and 1b, while grade 2 tumors were located intradurally.

Results

Of 389 PAs, 292 (75.1%) were surrounded by a bilayer structure formed by the DS and the residual PG and classified as grade 1a, 63 (16.2%) had lobulated or daughter tumors resulting from the thinning or absence of the residual PG and subsequently rendering the bilayer weaker were classified as Grade 1b, and the remaining 34 (8.7%) PAs that broke through the DS or traversed the diaphragmic opening and encased suprasellar neurovascular structures were classified as Grade 2. We found that the gross total removal of the suprasellar part of grade 1a, 1b, and 2 PAs decreased with grading (88.4%, 71.4%, and 61.8%, respectively). The rate of major operative complications, including cerebrospinal fluid leakage, hemorrhage, and death, increased with grading.

Conclusions

It is essential to identify whether PAs with suprasellar extension are located extradurally or intradurally, which depends on whether the bilayer structure is intact. PAs with an intact bilayer structure were classified as grade 1. These were extradural and usually had good surgical outcomes and lower complications. PAs with no bilayer structure surrounding them were classified as grade 2. These were intradural, connected to the cranial cavity, and had increased surgical complications and a lower rate of gross total removal. Different surgical strategies should be adopted for extradural and intradural PAs.

Anatomic and histologic features of diaphragma sellae that effects the suprasellar extension

This study aimed to determine the anatomical and histological features of diaphragma sellae that affect the suprasellar extension of intrasellar tumours. Twenty-four fresh adult cadavers were dissected for the study. Diaphragma sellae and pituitary capsules with sellar structures were resected. The diaphragma sellae was anatomically reviewed in detail. Immunohistochemical staining was performed for collagen types I, II, III, and IV. We examined the suprasellar growth of 13 sellar tumours extending superiorly through the diaphragma sellae by performing a series of 2704 endoscopic transnasal operations to analyse the anatomic and histologic results of the study. The diameter of the foramen of diaphragma sellae varied between specimens. Of 24 specimens, the diaphragma sellae in five (21%) had a tight-type foramen and those in 19 (79%) were more spacious. An increased expression of collagen types I and IV was observed in the pituitary capsule and the diaphragma sellae. In this clinical series, we observed that all types of sellar tumours could expand through the foramen. We observed radiologically and intraoperatively that the diaphragma sellae was displaced laterally and formed a dome in two cases with an adenoma extending to the suprasellar area. Two types of suprasellar extension through the diaphragma sellae are possible: 1) The collagen structure of diaphragma sellae can be destroyed by invasive tumours; 2) The morphology of the foramen of the diaphragma sellae facilitates suprasellar tumoural extension. All sellar tumours, including non-invasive cystic tumours, may invade the suprasellar area by expanding through the foramen of the diaphragma sellae.

Pituitary Adenomas and Invasiveness from Anatomo-Surgical, Radiological, and Histological Perspectives: A Systematic Literature Review

Invasiveness in pituitary adenomas has been defined and investigated from multiple perspectives, with varying results when its predictive value is considered. A systematic literature review, following PRISMA guidelines, was performed, searching PubMed and Scopus databases with terms that included molecular markers, histological, radiological, anatomical and surgical data on invasiveness of pituitary adenomas. The results showed that differing views are still present for anatomical aspects of the sellar region that are relevant to the concept of invasiveness; radiological and histological diagnoses are still limited, but might improve in the future, especially if they are related to surgical findings, which have become more accurate thanks to the introduction of the endoscope. The aim is to achieve a correct distinction between truly invasive pituitary adenomas from those that, in contrast, present with extension in the parasellar area through natural pathways. At present, diagnosis of invasiveness should be based on a comprehensive analysis of radiological, intra-operative and histological findings.

Predictive modeling for pituitary adenomas: single center experience in 501 consecutive patients

BACKGROUND

Personalized postoperative management of patients with pituitary adenomas requires an early risk stratification system.

METHODS

We reviewed 501 cases operated between 10/27/2011 and 5/5/2016 by a single neurosurgeon. We determined biochemical remission and tumor resection at 3 months, and biochemical recurrence, tumor recurrence, radiation and reoperation during follow-up. We considered age, gender, tumor diameter, cavernous sinus invasion (CSI) by MRI, diagnostic category (clinical, biochemical and immunohistochemical), and proliferation markers in a Cox proportional hazards model. We built predictive models with the significant parameters and used Kaplan-Meier survival curves for time-dependent analyses.

RESULTS

The 501 cases comprised 141 functional and 360 nonfunctional adenomas. Tumor diameter, CSI, and ki-67 index predicted long-term events. Model 1 (CSI, diameter ≥ 2.9 cm and ki-67 > 3%) identified 18 (3.6%) adenomas and predicted persistent hypersecretory syndrome and residual tumor with 98.7% specificity (OR 8.6; CI 3.0-24.7). Model 2 (ki-67 > 3% and CSI) identified 48 (9.6%) adenomas and had 93.1% specificity (OR 3.3; CI 1.8-6.0). Model 3 (ki-67 > 3%, mitoses and p53, former "atypical" adenoma) identified 26 (5.2%) adenomas and had 96.0% specificity (OR 2.3; CI 1.0-5.0). Model 1 best predicted the long-term event-free survival and was strengthened when Knosp 3-4 CSI grades were used. Model 2 better identified the smaller adenomas at risk. Among the WHO 2017 special PA subtypes, patients with silent corticotroph adenoma had a lower event-free survival than ACTH-negative nonfunctional adenomas.

CONCLUSION

Use of CSI, ki-67 and tumor diameter in prediction models facilitates tailored surveillance and management of patients with pituitary adenomas.

Associations of Ki-67 Labeling Index with Clinical and Paraclinical Features of Growth Hormone-Secreting Pituitary Adenomas: A Single Center Report from Iran

BACKGROUND

Acromegaly is a rare disorder resulting from benign growth hormone (GH)-secreting pituitary adenomas in 90% of the cases. In recent years, many researchers have studied the Ki-67 index level of pituitary tumors and its relationship with demographics, biochemical parameters, clinical behavior, and recurrence rate.

OBJECTIVES

This study aimed to evaluate the correlation of Ki-67 index level with clinicoradiological and endocrinological parameters in confirmed GH-secreting pituitary adenomas, as well as with the surgical response and medical treatment after surgery.

METHODS

We collected the medical and pathologic records of 49 patients with GH-secreting pituitary adenoma who underwent surgeries from 2008 to 2017 in Shariati hospital affiliated to Tehran University of Medical Sciences.

RESULTS

According to MRI reports, 94% of the tumors were macroadenomas. The MRI findings also revealed the median maximal adenoma diameter of 18.5 mm. About 40% of the patients achieved remission three months after the surgery. Younger patients had a significantly higher Ki-67 index level (P = 0.036). We did not observe any significant difference in the Ki-67 index level regarding gender, tumor type, maximal tumor diameter, tumor invasiveness, tumor secretory type, and remission. Interestingly, the Ki-67 index level was negatively correlated with the insulin-like growth factor-1 (IGF-1) level at the last follow-up (P = 0.02). In logistic regression analysis, patients with higher preoperative GH serum levels had a better outcome.

CONCLUSIONS

Our results indicated a negative correlation between age and Ki-67 index level. However, there was no association between the Ki-67 index level and some tumor behaviors, as well as short- and long-term remission.

Epidemiological variations of aggressive growth hormone-secreting adenomas

Acromegaly is a chronic disorder characterized by increased morbidity and mortality in uncontrolled patients. Growth hormone-secreting pituitary adenoma is the hallmark in the majority of cases, generally considered as benign due to lack of distant metastases. However, clinical behavior in a certain proportion of these adenomas could be quite aggressive, causing difficulties in their management. Aggressive pituitary adenomas have some clinical, radiological, ultrastructural and molecular features in common and they are usually resistant to the standard treatment. In the recent years, efforts have been made to define the most appropriate markers of such adenomas that would allow an early detection and efficient individualized therapeutic strategy. The aim of this review is to give an update on epidemiology and certain markers predicting aggressive behavior of somatotropinomas.