Endocrine Abstracts

Introduction: Meningiomas, already one of the most frequent types of primary central nervous system tumors, have been increasing in incidence in the past decade. Considering their location and histologic particularities, radiation therapy (RT), alone or in combination with neurosurgery, is often necessary and can have a negative impact on adjacent structures such as the pituitary gland. More studies investigating the endocrinologic disturbances in this pathology are necessary in order to meet the needs for developing a specific protocol.

Design: We compiled a case series of patients diagnosed with perisellar meningiomas between 2007-2022, who underwent endocrinologic evaluation in our clinic.

Results: Seven cases were found, six females and one male, aged 57-68 years. Onset of symptoms was reported in three cases, one presented with hypopituitarism and two patients with left palpebral ptosis. Six lesions had cavernous sinus invasion and one was located in the left cerebellopontine angle. Tumor dimensions varied from 25/27/25 mm to 22/47/34 mm. Neurosurgery was performed in two cases, one for a parietal lesion in a meningiomatosis patient and one for a sellar meningioma. Histopathologic exam revealed meningothelial meningiomas in both cases. Six patients underwent Gamma Knife radiation therapy. One patient received anti-inflammatory doses of glucocorticoids for almost 2 years prior RT. Hormonal evaluation was performed using basal determinations and no dynamic tests were performed. Endocrinologic assessment prior to RT was available in three cases, one investigating only the adrenal axis, one in the patient receiving glucocorticoids, showing mildly suppressed TSH with normal freeT4, which normalized at the end of the treatment and one in the hypopituitarism case. Mean time from RT until last endocrine workup was 4.8 years (1-11 years). Two patients were on levothyroxine treatment for primary hypothyroidism and apart from the patient with hypopituitarism, the remaining cases had normal thyroid, adrenal and gonadal function. Three patients had elevated prolactin levels, two before treatment and another at one year after RT. Two patients had decreased IGF-1 levels, measured at 2 and 6 years, respectively after RT.

Conclusions: Pituitary disturbances can occur in a wide time frame after RT and active surveillance must be done, balancing over- and under-testing. There is a need for a dedicated protocol for this pathology with adequate selection criteria, adjusted testing intervals and use of appropriate tests in order to identify subclinical deficiencies. Until then, clinicians should aim at correctly documenting radiation therapy dosages, and emphasizing the importance of repeated testing over the years.