Giant Non-Functioning Pituitary Adenoma: Clinical Characteristics and Therapeutic Outcomes

Abstract

Background Giant pituitary adenoma (≥4 cm) is a rare tumor whose clinical features and prognosis are not well known. Aim To evaluate the clinical characteristics and therapeutic outcomes of giant non-functioning PA (gNFPA). Patients and Methods A retrospective multicenter study of gNFPA patients diagnosed in a 12-year period was performed. In each patient, clinical data and therapeutic outcomes were registered. Results Forty patients (24 men, age 54.2 ± 16.2 years) were studied. The maximum tumor diameter [median (interquartile range)] was 4.6 cm (4.1–5.1). Women had larger tumors [4.8 cm (4.2–5.4) vs. 4.5 cm (4.0–4.9); p=0.048]. Hypopituitarism [partial (n=22, 55%) or complete (n=9, 22.5%)] at diagnosis was present in 77.5% of the patients. Visual field defects were found in 90.9%. The most used surgical technique was endoscopic endonasal transsphenoidal (EET) surgery (n=31, 77.5%). Radiotherapy was used in 11 (27.5%) patients (median dose 50.4 Gy, range 50–54). Thirty-seven patients were followed for 36 months (10–67 months). Although more than half of these patients showed tumor persistence (n=25, 67.6%), tumor size was significantly reduced [0.8 cm (0–2.5); p<0.001]. At last visit, 12 patients (32.4%) showed absence of tumor on MRI. Hypopituitarism rate was similar (75.0%), although with significant changes (p<0.001) in the distribution of the type of hypopituitarism. The absence of tumor at the last visit was positively associated with positive immunohistochemical staining for FSH (p=0.01) and LH (p=0.006) and negatively with female sex (p=0.011), cavernous sinus invasion (p=0.005) and the presence of Knosp grade 4 (p=0.013). Conclusion gNFPAs are more frequent in men but tumors are larger in women. Surgical treatment is followed by a complete tumor resection rate of approximately 30%. Positive immunostaining for gonadotropins is associated with tumor absence at last revision, while female sex and invasion of the cavernous sinuses with tumor persistence.

Prediction of the Recurrence of Non-Functioning Pituitary Adenomas Using Preoperative Supra-Intra Sellar Volume and Tumor-Carotid Distance

“…On the one hand, this value represents a quantification of the difficulty of total resection during transsphenoidal surgery. Patients with residual tumors have a greater risk of progression postoperatively according to previous studies ( 5 , 15 – 18 ). The relapse rate was higher after 10 years of follow-up than after only 5 years of follow-up in patients with a residual tumor.…”

“…NFPAs are benign intracranial tumors arising from adenohypophyseal cells. Patients usually visit the clinic much later than the time of disease onset, with symptoms caused by the compressed tissue surrounding the macroadenoma ( 1 , 5 ). Therefore, the treatment and prognostic factors for NFPAs should be taken seriously.…”

“…Most patients present with headaches, hormone disorders, visual impairment, or cranial nerve palsy. The diagnosis of most NFPAs is usually delayed by a mean time of 1.96 ± 2.9 years due to the absence of endocrine symptoms ( 4 , 5 ). Complete surgical resection can only be achieved in approximately 40–50% of all patients, although surgery is still the first-line strategy in NFPAs ( 6 ).…”

Hypogonadism in Male Patients with Pituitary Adenoma and Its Related Mechanism: A Review of Literature

“…It has previously been found that, at the time of presentation, approximately 73–93% of patients with macroprolactinoma had evidence of FSH and LH deficiencies [ 17 ]. Fallah et al [ 18 ] noted a rate of approximately 60% for gonadal hormone abnormalities in macroadenomas, while, in a study on non-functioning adenomas by Iglesias et al [ 19 ], it was found that the gonadal axis was most often affected by pituitary adenomas, with a rate of 62.5% of abnormalities. The effects of various types of saddle lesions on male gonadal function have been described [ 20 ].…”

“…The pituitary dysfunctions included gonadal dysfunction, thyrotropic dysfunction, and corticotropic dysfunction; the rate of dysfunction in these three axes varied depending on the tumor characteristics of the study population. For gonadal axis dysfunction, as judged by the hormone levels alone, the preoperative dysfunction rate was approximately 25%; studies by Fallah et al [ 18 ] and Iglesias et al [ 19 ] reported gonadal axis hormone abnormalities of 61.3% and 62.5%, respectively. After surgical interventions, more than 80% of the patients in these studies had their gonadal axis hormone levels restored to levels similar to those before surgery; however, the percentage of patients with worse function was significantly higher than the percentage of patients with elevated function [ 57 ].…”