Ectopic pituitary adenoma associated with an empty sella: a case report and review of the literature

Clinical and radiological presentation of parasellar ectopic pituitary adenomas: case series and systematic review of the literature

PURPOSE

Parasellar ectopic pituitary adenomas (pEPAs) are extremely rare tumors located out of the sella turcica. PEPAs are heterogeneous entities in terms of anatomical localization and secretion of anterior pituitary hormones.

METHODS

Multicenter retrospective study. Clinical charts' consultation of patients diagnosed with parasellar lesions, to identify all subjects fulfilling the diagnostic criteria of parasellar EPAs. Systematic review of the literature focused on the medical management of prolactin-secreting pEPAs and on the prevalence of radiological bone invasion in pEPAs.

RESULTS

We identified four cases of pEPAs: (1) 54-year-old female with a prolactin-secreting suprasellar EPA successfully treated with cabergoline; (2) 74-year-old male with a non-functioning EPA of the sphenoidal sinus treated with endoscopic transsphenoidal surgery; (3) 75-year-old female with a giant lesion of the skull base (maximum diameter 7.2 cm) diagnosed as a non-functioning EPA after biopsy; (4) 49-year-old male with a silent corticotroph EPA of the sphenoidal sinus and clivus. Three out of four cases had radiological evidence of invasion of the surrounding bone structures. A systematic review of the literature highlighted that medical therapy can be effective in prolactin-secreting pEPAs. Overall, we found mention of local invasiveness in 65/147 cases (44.2%), confirmed by radiological signs of bone invasion/erosion.

CONCLUSION

Our experience confirms the heterogeneity of pEPAs in terms of clinical and radiological presentation, as well as hormone secretion. PEPAs show a high frequency of radiological bone invasion, though similar to that of sellar pituitary adenomas. Although extremely rare, pEPAs need to be considered in the differential diagnosis of parasellar lesions.

Ectopic GH-secreting pituitary adenoma of the clivus: systematic literature review of a challenging tumour

PURPOSE

Acromegaly is usually due to growth hormone (GH)-secreting pituitary adenomas, but it may be exceptionally caused by GH-secreting ectopic pituitary adenomas (EPA). EPA are defined as extra-sellar pituitary tumours, extra- or intra-cranially sited, entirely separated from the pituitary stalk and gland. The aim of the study is to address the challenges in the management of clival GHEPA.

METHODS

We reported a case of a 53-year-old acromegalic patient with a primary clival GHEPA and reviewed systematically the relevant English literature between 1975 and 2019, in keeping with the PRISMA guidelines.

RESULTS

Four cases of primary clival GHEPA have been described in literature apart from ours. All patients presented with acromegalic features, elevated circulating GH and/or insulin-like growth factor-1 levels. Hyperprolactinemia and empty sella were described in two cases, respectively. These tumours show the typical imaging characteristics of pituitary adenomas, but their neuroradiological diagnosis may be challenging due to their sizes and the difficulty in defining the absence of connections with the pituitary fossa.

CONCLUSION

Although primary clival GHEPA are exceedingly rare, even if likely under-reported in literature, they should be considered in the differential diagnosis of clival tumours because of their specific management. Surgery represents the first-line treatment option, while medical and radiation therapies can be adopted as neo-adjuvant, adjuvant or primary treatments according to tumour and patient characteristics.

Variability in Clinical Presentation and Pathologic Implications of Ectopic Pituitary Tumors: Critical Review of Literature

OBJECTIVE

Pituitary tumors are common, well-described skull base tumors of sellar origin. However, there are reports of rare ectopic pituitary tumors that are found exclusively outside of the sella turcica. Ectopic pituitary tumors have not been holistically analyzed. This study describes presentation and clinical patterns found among patients with ectopic pituitary tumors.

METHODS

A comprehensive review of the literature was performed for clinical descriptions of ectopic pituitary tumors. Reports of 85 applicable cases were evaluated.

RESULTS

The most common locations of ectopic pituitary tumors were the sphenoid sinus, clivus, suprasellar space, nasopharynx, and cavernous sinus. The majority of ectopic pituitary tumors were reported as being functional secretory tumors; they were statistically significantly more likely to be functional tumors than sellar pituitary tumors. Adrenocorticotrophic hormone, prolactin, growth hormone, and thyroid-stimulating hormone-secreting tumors were most commonly found. Bone invasion was reported in more than one third of the cases, and malignant transformations were reported in 6 cases. A large majority of patients presented with hormonal, neurologic, or physiologic symptoms.

CONCLUSIONS

Ectopic pituitary tumors are a rare entity of pituitary tumors with a presentation that can mimic those of other skull base tumors. Clinical presentation often correlates to location of the tumor. Ectopic pituitary tumors were significantly more likely to be functional secretory tumors. They may also exhibit more aggressive behavior than sellar-located tumors. Ectopic pituitary tumors may be part of a spectrum of presenting pathologies. Further genetic or genomic analysis is necessary to better understand their pathogenesis and clinical presentations.

[Ectopia of the pituitary]

The adenohypophysis has a large intrasellar part and two small parts at the pituitary stalk and the pharynx. Near this extrasellar pituitary tissue, and also in sinus sphenoidalis and sinus cavernosus, ectopic pituitary adenomas can develop. They are indistinguishable in structure and function from usual intrasellar adenomas. The neurohypophysis can show dystopias within complex malformations. In so-called pituitary stalk interruption syndrome, a real ectopia of the neurohypophysis is found at the eminentia mediana of the hypothalamus. Ectopic tissue in the pituitary is extremely rare: foci of ganglionic cells were found in the neurohypophysis and adrenocortical tissue in the adenohypophysis. Focal squamous epithelia in the anterior pituitary are a common finding but they are rather metaplastic from parenchymal cells than ectopic tissue. Small foci of ectopic salivary gland tissue are not rare in the intermediate zone.

[Ectopic pituitary adenoma associated with empty sella turcica]

Ectopic pituitary adenoma is a rare entity that is most commonly located in the sphenoid sinus. We report a case of a patient with ectopic pituitary adenoma with no functional expression associated with empty sella turcica, which gives rise to a broad differential diagnosis. Although it is a benign neoplasm, necrosis is encountered in a proportion of cases. Magnetic resonance imaging is the diagnostic method of choice for hypothalamic-pituitary-related endocrine diseases with endoscopic biopsy for histological confirmation. It is important to include pituitary markers in the immunohistochemical diagnostic panel.

Ectopic Pituitary Adenomas Presenting as Sphenoid or Clival Lesions: Case Series and Management Recommendations

Background An ectopic pituitary adenoma presenting as a clival or sphenoid mass is a rare clinical occurrence that may mislead the clinician and result in unnecessary interventions or potential medicolegal consequences. Here, we present one of the largest multi-institutional case series and review the literature with an emphasis on radiological findings and critical preoperative workup. Methods Retrospective chart review. Results Nine patients were identified with ectopic pituitary adenomas of the sphenoid or clivus. There were four females and five males. Median age was 60 years old (range, 36-73 years). The most common presenting symptom was headache (56%). Five (56%) patients presented with a mass arising from the clivus while four (44%) presented with a mass in the sphenoid. Six (67%) patients demonstrated biochemical evidence of hypersecretion on full endocrinology panel. All masses showed evidence of enhancement with gadolinium with a propensity for adjacent bone involvement. Lesions also had a predilection for growth toward the cavernous sinus, carotid artery, or sellar floor. Surgical intervention was performed in eight patients (89%). In eight patients (89%), tumors demonstrated immunoreactivity to prolactin. Conclusions Pituitary adenomas can rarely present as an isolated sphenoid or clival mass. Lesions displayed similar magnetic resonance imaging findings with an erosive growth pattern toward the sellar floor, cavernous sinus, or adjacent carotid artery. Patients with clival or parasellar lesions with comparable features should have a preoperative workup which includes prolactin level and alert the physician to consider an ectopic pituitary adenoma in the differential to prevent unnecessary surgery and potential complications.

Ectopic pituitary adenoma with empty sella in the setting of MEN-1 syndrome: detection with 68Ga-DOTANOC PET/CT

Patients with multiple endocrine neoplasia type-1 syndromes are known to have neuroendocrine tumors (NETs) involving the pituitary and gastroenteropancreatic region, in addition to the presence of parathyroid abnormalities. In rare instances adenomas in the ectopic pituitary gland have been reported. As pituitary gland and pituitary adenomas are known to express SSTRs, somatostatin receptor scintigraphy can be used for imaging. Somatostatin receptor-based PET/CT imaging using 68Ga-DOTANOC has become a popular noninvasive imaging modality for evaluation of patients with NETs. The application of 68Ga-DOTANOC PET/CT can be extended to multiple endocrine neoplasia type 1 patients, as is evident from this case study.