Vanishing pituitary mass revealed by timely magnetic resonance imaging: examples of spontaneous resolution of nonfunctioning pituitary adenoma

SPONTANEOUS RESOLUTION OF A NONFUNCTIONING PITUITARY ADENOMA OVER ONE-MONTH PERIOD: A CASE REPORT

Spontaneous resolution of nonfunctioning pituitary adenoma after hemorrhagic apoplexy is a rare clinical entity of unknown etiology and is defined as disappearance of a tumor without any specific treatment. Here we present a 54-year-old male patient who presented with acute onset of severe headache, vomiting, photophobia, and sonophobia. He was referred to brain computed tomography, which showed a 16x12x16 mm tumor mass located in the sellar region with signs of hemorrhage. Endocrinologic evaluation was consistent with under-function of pituitary gonadotropic cells. Magnetic resonance imaging (MRI) performed ten days later was consistent with hemorrhagic apoplexy of the pituitary adenoma. The patient’s symptoms resolved after conservative treatment with dexamethasone, but he was scheduled for elective pituitary surgery. Preoperative MRI was performed one month after the first one and disclosed normal pituitary gland without any signs of adenoma. Our case is remarkable due to the fact that spontaneous remission of pituitary adenoma occurred within the first month, which is the shortest interval reported to date. Our case highlights the importance of conservative therapy as the first-line treatment for pituitary apoplexy in the absence of neurological impairment, since spontaneous remission may occur in a short time interval.

A curious case of vanishing pituitary adenoma

Pituitary macroadenoma is the most common suprasellar lesion in adults. If symptomatic, it is managed surgically via transsphenoidal resection. Patients commonly present with headache and visual disturbances. If the tumour is large enough, it may have mass effect and patient may present with symptoms of elevated intracranial pressure like severe headache, nausea and vomiting. Functional adenomas may cause endocrine dysfunction. Here, we present a case of pituitary macroadenoma in a young adult female who presented with headache. Initial CT and MRI revealed a pituitary macroadenoma. However, repeat imaging done preoperatively showed complete regression of the lesion and a normal appearing pituitary gland.

Empty Sella in the Making

BACKGROUND

Pituitary apoplexy may occur when a large tumor compresses or outgrows its nutrient supply, resulting in ischemic necrosis and hemorrhage. Although once deemed a neurosurgical emergency, increasing evidence suggests that conservative management of pituitary apoplexy leads to favorable neuro-ophthalmologic and endocrinologic outcomes as well. Spontaneous remission after pituitary apoplexy has been described in functioning pituitary adenomas, but it is a rare occurrence in nonfunctioning tumors.

CASE DESCRIPTION

We report a man that presented with pituitary apoplexy of a nonfunctioning pituitary macroadenoma that was managed conservatively and treated hormonally for hypopituitarism during a 2-year follow-up period, with serial neuroimaging demonstrating significant tumor volume reduction with almost complete resolution resulting in partial empty sella. In addition, a short literature review was performed pertaining to the management of pituitary apoplexy with emphasis on a more conservative approach.

CONCLUSIONS

A subset of patients with pituitary apoplexy without altered consciousness and nonprogressive or mild ophthalmologic deficits may be managed conservatively; however, lifelong periodic assessment, preferably by a specialized multidisciplinary pituitary team, is essential until clinical outcomes become clear.

Spontaneous preoperative pituitary adenoma resolution following apoplexy: a case presentation and literature review

Purpose: We aim to more fully understand the incidence and natural history of spontaneously resolving non-functioning pituitary adenomas (NFPAs).Methods: We report a case of spontaneous complete resolution of a NFPA revealed by preoperative magnetic resonance imaging. In addition, we searched all major databases and neurosurgery journals to perform a comprehensive literature review of all previously reported cases of spontaneously resolving NFPAs. We discuss how these cases may contribute to our understanding of the natural course for non-functional pituitary adenomas.Results: To date, only twelve cases of spontaneously resolving nonfunctional pituitary adenomas have previously been reported. The presented case is the first reported spontaneously resolved nonfunctioning pituitary adenoma to recur. In all cases, apoplexy resulted in resolution of mass effect, obviating the need for surgical decompression.Conclusions: In all NFPA cases, the preoperative MRI should always be studied closely before surgery is initiated. Additionally, because we have demonstrated that the adenoma may regrow after spontaneous regression following apoplexy, these patients should be followed with regular serial MRIs to monitor for recurrence.

Quantification of specific growth patterns and frequency of the empty sella phenomenon in growth hormone-secreting pituitary adenomas

PURPOSE

To assess and quantify the prevalence and co-occurence of a sellar floor lowering and empty sella phenomenon in patients with GH (growth hormone)-secreting pituitary adenoma.

METHODS

A total number of 159 acromegalic patients were included in this study, as well as two control groups (150 patients with non-GH-secreting adenomas and 50 patients without pituitary adenomas). Magnetic resonance images of all patients were evaluated for presence of an empty sella, downward and lateral tumor extension, and maximum superoinferior diameter of the mass. Additionally, these values were correlated with growth hormone and IGF-1 levels.

RESULTS

The empty sella phenomenon was detected significantly more often in patients with a GH-secreting adenoma with a prevalence of 22% vs. 5.3% in non-GH-secreting adenomas (p < 0.001) or 8% in the healthy control group (p = .036). Moreover, GH-secreting adenomas presented with a significant rate of downward tumor extension (74.8% vs. 35.5%; p < 0.001), whose extent correlated inversely but weakly with the GH hormone level (r = - 0.17; p = .036). It was also found that a decreased superoinferior diameter and higher ratio of intrasellar to suprasellar extension are predictive quantitative values for the presence of a GH-secreting adenoma (area under curve, 0.712).

CONCLUSIONS

GH-secreting pituitary adenomas are frequently associated with an empty sella phenomenon. Moreover, GH-secreting adenomas are frequently accompanied by an enhanced, quantitatively measurable impression of the sellar floor. Hypothetically, this is caused by tumor-induced local bone remodeling processes.

Clinical characteristics of acromegalic patients with empty sella and their outcomes following transsphenoidal surgery

PURPOSE

To analyze the clinical characteristics of acromegalic patients with empty sella (ES, herniation of the subarachnoid space within the sella turcica) and the impact of ES on transsphenoidal surgery in such patients.

METHODS

Seventy-eight patients, newly diagnosed with acromegaly who underwent transsphenoidal surgery were included. ES was defined as the pituitary gland and adenoma occupying less than 50% of the sella turcica on midsagittal magnetic resonance (MR) imaging.

RESULTS

Twelve patients (15.4%), predominantly female (10 women, p = .047), had ES in preoperative MR imaging. ES patients had smaller mean tumor diameter (6.3 mm) than non-ES patients (11.2 mm, p = .001). In preoperative MR imaging, occult adenoma was found in three (25%) ES and three (4.5%) non-ES patients (p = .044). Intraoperative cerebrospinal fluid (CSF) leakage was more frequent in the ES patients than in the non-ES patients (58.3 vs. 25.8%, p = .024). This led to an increased rate of sellar floor reconstruction using abdominal fat and/or postoperative lumber drainage in the ES patients (ES: 41.7 vs. non-ES: 16.7%, p = .063). Endocrinological remission after surgery was more frequent in the non-ES patients (72.7%) than in the ES patients (58.3%) (p = .248).

CONCLUSIONS

Co-existence of acromegaly with ES is not rare, and is associated with occult adenoma, intra/postoperative CSF leakage, and a worse endocrinological outcome after transsphenoidal surgery; although, the underlying mechanism remains unclear.

Brain and Optic Chiasm Herniation into Sella after Pituitary Tumor Apoplexy

Brain and optic chiasm herniation has been rarely reported following dopamine agonist treatment for large prolactinomas. We report a case of brain and optical chiasm herniation, secondary to an empty sella due to apoplexy of a prolactinoma, and we focus on the specific presentation of this case. A 32-year-old female presented to a neurologist complaining of headaches. Her past medical history was significant for acute vision loss in both eyes accompanied by right third nerve palsy when she was 16 years old. She does not recall any endocrine or imaging evaluation at that time and she had spontaneous partial recovery of left eye vision within 3 months, with permanent blindness of right eye. She did not return to any follow-up until her neurologist consultation. Brain magnetic resonance imaging (MRI) revealed herniation of frontal lobe and optic chiasm into the pituitary sella, as well as a pituitary hypointense lesion measuring 5 mm × 5 mm after gadolinium injection. Prolactin levels were 206 ng/ml (4.79-23.3 ng/ml). Repeated prolactin was 258 ng/ml (4.79-23.3 ng/ml). She was started on bromocriptine 2.5 mg/day. Prolactin levels and menstrual cycles normalized. A repeat brain MRI performed 5 months later showed disappearance of pituitary mass, with no changes in brain and chiasmal herniation. To our knowledge, this is the first reported case of brain associated with chiasm herniation secondary to pituitary apoplexy of a prolactinoma. In conclusion, this case highlights that frontal lobe herniation in combination with optic chiasm herniation can be a complication of pituitary tumor apoplexy. Long-term surveillance of patients with pituitary apoplexy is warranted to detect delayed complications.

Pituitary adenomas

Pituitary adenomas are by far the most common sellar tumor and magnetic resonance imaging is the modality of choice for their detection and characterization. However, most of these neoplasms are asymptomatic and frequently incidentally visualized. One also has to be aware of common other incidental findings and normal age-related changes in the appearance of the gland. By convention, 10 mm is used as the size threshold to separate macroadenomas from microadenomas. For microadenomas, imaging is primarily used for lesion detection and localization, whereas with macroadenomas, the goal is to establish whether the mass represents a pituitary tumor or some other lesion and to precisely delineate its extent.