Gangliocytomas in the sellar region

Observation of Clinicopathologic Features of Pituitary Adenoma With Neuronal Differentiation

OBJECTIVE

To investigate the clinicopathologic features of pituitary adenoma with neuronal differentiation.

METHODS

Four patients with mixed gangliocytoma-pituitary adenomas between January 2011 and January 2021 and 111 new-onset patients with adenomas between January 2019 and June 2021 who attended the First Affiliated Hospital of Fujian Medical University were included in the study. The histological and immunohistochemical findings were analyzed. Neuronal differentiation marker staining was performed on new-onset adenomas, and the related literature was reviewed.

RESULTS

Altogether, more than 100 mixed gangliocytoma-pituitary adenoma cases have been reported in the literature until now, of which pituitary-specific POU-class homeodomain transcription 1 (PIT1) positive adenomas are more frequently observed. In the present study, all 4 patients we described were female, aged 29 to 53 years (mean 39 years). Clinically, 3/4 patients presented with acromegaly, and 1/2 patients presented with headache. Histologically, the tumor was composed of two distinct mixed components. The one was a population of neoplastic ganglionic cells with large nuclei, prominent nucleoli, and abundant basophilic cytoplasm embedded in a fibrillary background. Stains of chromograninA (CgA), synaptophysin (Syn), Calretinin (CR) were positive. Axotomy-like expression was observed in neurofilament (NF) staining. PIT1 was expressed in partial ganglionic cells in all cases. The other component was a population of small uniform cells with round nuclei and acidophilic cytoplasm. Prolactin (PRL) and growth hormone (GH) were positive in all 4 cases. PIT1 was positive in the nuclei of adenomas. Although adenomas and ganglionic regions varied in histology, there was a population of cells with neuronal differentiation expressing PIT1. Additionally, axotomy-like expression of NF staining could be seen in a distant area of adenoma regions. A total of 111 cases of adenomas without ganglionic cells were included in this study, including 7 cases with neuronal differentiation. Among them, 4 cases were prolactinomas, 2 cases were somatotroph adenomas, and 1 case was corticotroph adenoma. 6/7 cases were PIT1-positive adenomas. And the remaining one case is T-PIT-positive adenoma.

CONCLUSIONS

Mixed gangliocytoma-pituitary adenomas are rare tumors with neuronal differentiation. The majority of MGAs are associated with endocrinopathies, mainly acromegaly. Our results suggest that PIT1-positive pituitary adenomas may have neural differentiation potential, which may not be unusual. This indication supports the possibility that the neuronal transdifferentiation of adenomatous cells is a possible mechanism, and the underlying mechanism requires further elucidation.

Pituitary Gangliocytoma Producing TSH and TRH: A Review of "Gangliocytomas of the Sellar Region"

PURPOSE

Pituitary gangliocytomas (GCs) are rare neuronal tumors that present with endocrinological disorders, such as acromegaly, amenorrhea-galactorrhea syndrome, and Cushing's disease. Most pituitary GCs coexist with pituitary adenomas pathologically and are diagnosed as mixed gangliocytoma-adenomas. Herein, we report a case of 45-year-old man who presented with the syndrome of inappropriate secretion of thyroid-stimulating hormone (SITSH) and discuss the pathogenesis of pituitary GCs.

METHODS

Pituitary magnetic resonance imaging showed an 8-mm homogeneous and poorly enhanced mass inside the pituitary gland. Endoscopic transsphenoidal surgery was performed under a preoperative diagnosis of thyrotroph adenoma. However, the tumor was finally diagnosed as gangliocytoma without an adenomatous component. The tumor was further analyzed via immunohistochemistry and electron microscopy. Additionally, we searched MEDLINE and PubMed for previously published cases of isolated pituitary GCs and analyzed the reported clinicopathological findings.

RESULTS

The patient showed complete clinical and endocrinological recovery after an operation. The tumor was positive for thyrotropin (TSH), TSH-releasing hormone (TRH), Pit-1, GATA-2, and most neuronal markers. Electron microscopy demonstrated the presence of intracytoplasmic secretory granules and neuronal processes. Co-secreting hypothalamic and pituitary hormone inside the tumor indicated autocrine/paracrine endocrinological stimulation.

CONCLUSION

Herein, we report a case of SITSH caused by an isolated pituitary gangliocytoma, expressing both TSH and TRH, which, to our best knowledge, is the first reported case of such a condition. The multidirectional differentiation and multihormonal endocrine characteristics of these tumors indicate that they are a member of neuroendocrine neoplasms, further supporting that they are derived from neural crest cells.

AN INCIDENTAL COLLISION TUMOR OF THE SELLA TURCICA

Objective

To present a case describing an incidentally discovered pituitary mass that was found to be a collision tumor containing 2 distinct histologic cell types: (1) a growth hormone (GH)-secreting pituitary adenoma, and (2) a gangliocytoma.

Methods

Sellar gangliocytomas are very rare benign neuroblastic tumors that originate from the posterior pituitary. The majority are associated with pituitary adenomas. The co-existence of these 2 morphologically distinct tumors is known as a collision tumor, a rare disease entity of which the pathogenesis is not well understood. We present a case of a woman with an incidentally discovered pituitary mass that was found to be a collision tumor.

Results

A 44-year-old woman presented with an incidentally discovered pituitary mass and was found to have elevated insulin-like growth factor 1 (IGF-1) levels. The patient underwent endoscopic transsphenoidal excision of the pituitary mass. Histopathology of the tumor revealed a mixed pituitary adenoma that stained for GH and prolactin, and a gangliocytoma. Postoperatively, the patient developed temporary central adrenal insufficiency and permanent diabetes insipidus. Postoperative lab studies revealed a normal IGF-1 level, and a magnetic resonance imaging scan showed no residual or recurrent tumor.

Conclusion

While sellar gangliocytoma is a rare lesion, when it is present, a co-existing pituitary adenoma should also be suspected. Further investigation should be done to determine the pathophysiology of these collision tumors, which could be beneficial in guiding diagnosis and treatment.

Mixed gangliocytoma-pituitary adenoma in the sellar region: a large-scale single-center experience

BACKGROUND

Mixed gangliocytoma-pituitary adenoma is an extremely rare tumor occurring in the sellar region, histologically composed of both gangliocytic and pituitary adenomatous architectures. The histogenesis of these tumors remains unknown, and the diagnosis, treatment, and prognosis are yet to be fully understood.

METHODS

We retrospectively reviewed the clinical, radiological, and histopathological profiles from a series of 20 patients with sellar mixed gangliocytoma-pituitary adenomas. All patients underwent surgical tumorectomy via an endoscopic or microscopic transsphenoidal approach. Perioperative magnetic resonance imaging (MRI) and computed tomography (CT) data were reviewed. Immunohistochemical stains and electron microscopy examination were performed. Follow-up outcomes were presented.

RESULTS

This case series consisted of 13 females and seven males (age range, 20-59 years; mean age, 42.3 ± 11.2 years). Preoperative endocrine examination showed elevated growth hormone (GH) in nine patients and hyperprolactinemia in eight patients. The tumors were positive for GH in 15 cases, prolactin in 13 cases, adrenocorticotropic hormone in three cases, and thyroid-stimulating hormone in one case. Gross total resection was achieved in 15 patients, and subtotal resection in five patients. During an average follow-up period of 42.5 ± 29.0 months, no recurrence was noted.

CONCLUSIONS

The clinical and neuroimaging features of sellar mixed gangliocytoma-pituitary adenomas are non-specific, and invasion into the cavernous sinus is common. Surgical resection via a transsphenoidal approach is the preferred treatment, and the surgical outcomes are favorable. Moreover, our histopathological findings are more likely to support the theory that mixed gangliocytoma-pituitary adenoma originates from the neuronal transdifferentiation of adenomatous cells.

Transsphenoidal Surgery for Mixed Pituitary Gangliocytoma-Adenomas

BACKGROUND

Most sellar gangliocytomas are discovered with a concurrent pituitary adenoma, also known as a mixed gangliocytoma-adenoma (MGA). MGAs are rare, with fewer than 100 cases reported in the literature to date and only 1 previously documented surgical series. Because MGAs are radiologically indistinguishable from pituitary adenomas, they are often diagnosed after surgery. Combined with the paucity of clinical outcome data for these tumors, this makes their diagnosis and management challenging. Here we describe the clinical presentation and outcomes of 10 individuals who were diagnosed with a MGA at a single institution.

METHODS

This retrospective case series study included patients diagnosed with a combined sellar MGA between 1993 and 2016.

RESULTS

This series comprised 10 patients, mean age of 44 years (range, 28-63 years) diagnosed with an MGA. The mean tumor size was 1.6 cm (range, 0.4-2.4 cm). Five patients presented with acromegaly, and 1 patient had recurrent Cushing disease. Transsphenoidal surgery was performed in all cases, and gross total resection was achieved in 7 patients (70%). Histologically, 9 of the 10 MGAs were identified as mixed somatotroph adenoma-gangliocytomas. The median duration of follow-up was 74 months (range, 2-180 months). Following adjuvant treatment (n = 3), all patients with acromegaly (n = 4) achieved biochemical remission, and no patient experienced recurrence of the pituitary tumor with a median radiographic follow-up of 48 months.

CONCLUSIONS

MGAs are often associated with a hypersecretory adenoma. Transsphenoidal surgery is well tolerated by most patients, and when performed in combination with adjuvant therapy, a low rate of recurrence and reversal of preoperative endocrinopathy can be expected.

Gangliocytoma: outcome of a rare silent pituitary tumour

The most common finding in front of a pituitary incidentaloma is a silent pituitary adenoma. We describe a 59 years old woman with a pituitary gangliocytoma and her follow-up after 1 year. Hormonal exploration only evidenced partial corticotropic insufficiency. A trans-sphenoidal surgery was performed due to the tumour's suprasellar expansion. Gangliocytoma is a benign tumour of unknown prevalence, belonging to central nervous system tumour with neuronal differentiation, and 129 cases have been reported in the literature. growth hormone (GH), adrenocorticotropic hormone (ACTH) or prolactin secretions have been reported, as these ganglion cell-like mature neurons are usually mixed with secreting pituitary endocrine cells. We report a case with a pure gangliocytoma devoid of symptomatic endocrine secretion, not surrounded by pituitary endocrine tumour cells. Immunochemistry of the tumour was positive for hypothalamic growth hormone releasing hormone (GHRH) and pituitary hormones, such as GH and ACTH. Hence, this immunoexpression was not associated with peripheral hormonal secretions, suggesting biologically inactive hypothalamopituitary hormones.

Mixed Pituitary Gangliocytoma and Prolactinoma Resistant to the Cabergoline Treatment

BACKGROUND

A gangliocytoma rarely coexists with a pituitary adenoma in a sellar lesion. Herein, we describe our experience in treating a mixed gangliocytoma and prolactinoma of the pituitary gland.

CASE DESCRIPTION

A 16-year-old male presented with severe headache and vomiting. Magnetic resonance imaging showed a large pituitary tumor with hydrocephalus. Because of the increased levels of serum prolactin (PRL), we treated the patient with cabergoline, which decreased the tumor size and improved the hydrocephalus. Six months after the treatment, the tumor began to increase in size, despite the normalization of the PRL level with cabergoline treatment. An endoscopic transsphenoidal resection was performed and the tumor was mostly removed. Microscopic examination of the resected tumor showed a mixture of prototypical pituitary adenoma cells and the proliferation of mature ganglion cells. Immunohistochemistry showed that the ganglion cells were positively stained for synaptophysin, NeuN, and PRL as shown in the adenomatous component. A few cells were immunostained with both PRL and NeuN, and a few cells were immunopositive for nestin, but not PRL or synaptophysin.

CONCLUSIONS

Our findings showed the existence of cells that are phenotypically intermediate between ganglion cells and adenoma cells, and the existence of stem cell-like cells, which support the hypothesis that adenoma cells can transform into ganglion cells or that both ganglion and adenoma cells derive from common stem cells. Furthermore, the ganglion cells seemed to grow rapidly and independently of dopamine, which is in contrast to prototypical prolactinoma cells.