Pathogenesis, clinical features, and treatment of plurihormonal pituitary adenoma

Plurihormonal pituitary adenoma (PPA) is a type of pituitary tumor capable of producing two or more hormones and usually presents as an aggressive, large adenoma. As yet, its pathogenesis remains unclear. This is the first study to systematically summarize the underlying pathogenesis of PPA. The pathogenesis is related to plurihormonal primordial stem cells, co-transcription factors, hormone co-expression, differential gene expression, and cell transdifferentiation. We conducted a literature review of PPA and analyzed its clinical characteristics. We found that the average age of patients with PPA was approximately 40 years, and most showed only one clinical symptom. The most common manifestation was acromegaly. Currently, PPA is treated with surgical resection. However, recent studies suggest that immunotherapy may be a potentially effective treatment.

Somatostatin receptor expression and clinical outcome of multilineage pituitary tumours expressing PIT1 and SF1

The application of transcription factor immunohistochemistry to pituitary neuroendocrine tumour (PitNET) assessment has allowed identification of tumours that do not conform to a single lineage. Multilineage pituitary transcription factor 1 (PIT1) and steroidogenic factor 1 (SF1) PitNETs are a rare and relatively newly described tumour subtype. These tumours express both transcription factors and may also express combinations of hormones corresponding to both lineages. Histological and clinical characteristics can vary, and overall clinical behaviour and prognosis is not known. We describe the clinical outcomes and somatostatin receptor status (SSTR) of a series of nine cases identified from our cohort of pituitary tumours at Westmead Hospital. Eight PitNETs (88.9%) expressed growth hormone and caused acromegaly at presentation. Of the seven macrotumours that caused acromegaly, one had cavernous sinus invasion. The Ki-67 labeling index score ranged from 0.6% to 3.6%. About 88% of tumours that secreted excess growth hormone exhibited strong immunostaining for SSTR 2 and all tumours displayed weak immunoreactivity for SSTR5. In 62.5% of patients with acromegaly, cure was achieved after surgical resection. Somatostatin receptor ligands resulted in clinical remission in cases where medical treatment was initiated. There was no new tumour recurrence or regrowth over an overall mean follow-up period of 62.5 months.

A unique coexistence of a plurihormonal pituitary adenoma with granulomatous hypophysitis

Dual pathology in the pituitary gland is a unique phenomenon. Coexistence of a pituitary adenoma with primary hypophysitis has been reported rarely with very few cases in the literature. Among the primary hypophysitis, primary granulomatous subtype has been proposed to be idiopathic and autoimmune in nature. Plurihormonal pituitary adenomas produce hormones of more than one different pituitary cell lineage. Pituitary adenoma with a single hormonal content has been documented with concurrent primary granulomatous hypophysitis. The present case describes the unique coexistence of a plurihormonal adenoma showing somatotroph, lactotroph, and corticotroph lineage with primary granulomatous inflammation in the sellar region in a 36-year-old woman.

An Aggressive Plurihormonal Pituitary Adenoma With Thyrotropin, Growth Hormone, and Prolactin Excess

A 31-year-old gentleman presented with clinical hyperthyroidism, goiter, bitemporal hemianopia, and discordant thyroid function test. The high α-subunit and absence of throtropin (thyroid-stimulating hormone; TSH) response to thyrotropin-releasing hormone stimulation indicated a TSH-secreting pituitary tumor. Elevation in prolactin and growth hormone as well as secondary hypogonadism were also observed. A sellar-suprasellar mass displacing the optic chiasm was revealed upon magnetic resonance imaging. The patient was rendered euthyroid with carbimazole and Lugol's iodine before undergoing endoscopic transsphenoidal surgery. Due to the incomplete tumor excision during surgery, patient experienced recurrence of symptoms and rising thyroxine (T4) with nonsuppressed TSH. The histopathology examination demonstrated a plurihormonal tumor with positive immunohistochemical stain for TSH, growth hormone, and prolactin, with invasive and proliferative features. Subsequently he was initiated with a long-acting somatostatin analogue and underwent stereotactic radiosurgery. To date, his symptoms have improved, with a reduction of insulin-like growth factor 1 and normalization of other pituitary hormones as well as a slightly reduced size of the pituitary tumor.

Three cases of ectopic sphenoid sinus pituitary adenoma

<i><b>Introduction</b>: Ectopic sphenoid sinus pituitary adenoma is a rare tumour originating from embryologic remnants of Rathke's pouch. Although it is considered a clinically benign neoplasm, necrosis is encountered in 25% of cases and it can invade adjacent bone structures. <b>Aims</b>: To establish clinical, radiological and histopathological features of ectopic sphenoid sinus pituitary adenoma. <b>Material and methods: </b> Analysis of three cases: two females and one man, aged 61-70. <b>Results</b>: One patient presented with a unilateral hearing loss, the other two with headache and vertigo. They all suffered from type 2 diabetes mellitus. Neurological examination revealed no abnormality. Radiological imaging showed a sphenoid sinus space-occupying soft-tissue lesion with bone erosion in 2 cases and empty sella in 2 patients whereas one had a normal pituitary gland. All were operated on via the transnasal approach. Total resection was achieved in one patient and subtotal in two; in two cases we observed intact sellar dura and in one intact sellar floor. Histopathology showed immunoreactivity for synaptophysin in all cases and cytokeratin in two. The Ki-67 index was less than 2%. Immunohistochemical staining demonstrated growth hormone cells in all cases whereas prolactin and adrenocorticotropin in two. The patients were discharged home in good condition with no neurological deficits. <b>Conclusions</b>: Ectopic sphenoid sinus pituitary adenoma should always be considered in differential diagnosis of sphenoid sinus lesion in the elderly, especially in coexistence with empty sella or type 2 diabetes mellitus. Since ectopic sphenoid sinus pituitary adenoma is a benign lesion, surgical removal is an effective treatment. </i>.

Detection of programmed death ligand 1 protein and CD8+ lymphocyte infiltration in plurihormonal pituitary adenomas: A case report and review of the literatures

RATIONALE

Pituitary adenomas secreting two or more hormones were referred to the plurihormonal tumors. The management of this type of the tumor was tumor resection and amelioration of the unbalanced hormones. However, it washard to cure the plurihormonal adenomas, as they were usually refractory to the traditional treatment. New therapeutic methods were needed in dealing this tumor.

PATIENT CONCERNS

In this report, we described a patient who suffered from plurihormonal pituitary adenomas, with concomitant prolactin (PRL) and growth hormone (GH) secretion. The adenomas showed aggressive behaviors, which was giant, invasive, and refractory to bromocriptine treatments.

INTERVENTIONS

The patient underwent a surgical treatment.

DIAGNOSIS

The pathology together with clinical presentation and blood hormone test confirmed that it was PRL-GH secreting tumors.

OUTCOMES

Although a gross resection was achieved, the postoperative hormones were not normalized. There were also abundant programmed death ligand-1 proteins and CD8 lymphocyte infiltration in the tumor tissues.

LESSONS

Our results indicated immunotherapy as a promising treatment for this tumor. More studies were needed to investigate the possibility of the immunotherapy in pituitary adenomas.

Plurihormone secreting pituitary macroadenoma masquerading as thyrotoxicosis: Clinical presentation and diagnostic challenges

Thyroid stimulating hormone (TSH) secreting adenomas are the rarest type of pituitary adenomas (1:1000000 in the population; 0.2- 2.8% of adenomas). Plurihormonal thyrotropic adenomas are even rarer usually having cosecretion of growth hormone (GH) and prolactin. We report perhaps for the first time, TSH, GH, adrenocorticotrophic hormone (ACTH) and gonadotropins secreting pituitary macroadenoma diagnosed in a 40 year lady presenting with features of thyrotoxicosis for 5 months, amenorrhea for 3 months and newly diagnosed diabetes and hypertension for 2 months along with headache, nausea, and vomiting, who had acromegaloid habitus, grade-II goitre, increased uptake on Technitium-99 pertechnate thyroid scan (4.1%; normal: 0.24-3.34%), with increased T3 (5.98 pg/ ml; 1.5-4.1), increased T4 (2.34 ng/dl; 0.9-1.8), inappropriately high TSH (2.32 μIU/ml; 0.4-4.2), insulin like growth factor-1 (711 ng/ ml; 109-264), non-suppressed post-glucose GH (15.9 ng/ml; <1 ng/ml), normal estradiol (52 pg/ml; 21-251), inappropriately high luteinizing hormone (53.5 mIU/ml; 1.1-11.6), inappropriately high follicle stimulating hormone (59 mIU/ml; 3-14.4), non-suppressed overnight dexamethasone cortisol (5.8 mcg/dl; <2), elevated ACTH (58 pg/ml 5-15), withdrawal bleed on progestrogen challenge, bitemporal hemianopia on automated perimetry and pituitary macroadenoma on MRI imaging of sella. Thyroid hormone resistance was ruled out by documenting normal sex hormone binding globulin and ferritin levels. Her clinical and biochemical phenotype was not suggestive of multiple hormone resistance seen in pseudohypoparathyroidism. This report intends to highlight the challenges in the diagnosis of plurihormonal thyrotropic adenoma.