The clinicopathological features of pituicytoma and the differential diagnosis of sellar glioma

An elusive case of malignant optic nerve glioma with a suprasellar mass

A 67-year-old man with multiple comorbidities presented with 3 weeks of orbital pain, proptosis, and no light perception vision in the left eye. Examination was notable for a left orbital apex syndrome with CN III, VI palsies, an optic neuropathy, and central retinal vein occlusion. Magnetic resonance imaging of the orbits was notable for extensive enhancement, enlargement, and T2 hyperintensity of the optic nerve, with perineural sheath enhancement, and chiasmal hyperintensity. Inflammatory workup and lumbar puncture were unremarkable. No improvement was seen after a 3-day course of intravenous solumedrol. Initial optic nerve biopsy revealed necrotic nerve tissue, macrophage infiltration, increased vascularization, and peripheral gliosis. The volume of tissue was inadequate for genomic analysis. The patient was lost to follow-up but returned 5 months later with right-sided vision loss. Repeat neuroimaging showed a new suprasellar mass and progressive expansion and enhancement of both optic nerves. Biopsies of the suprasellar mass and left nerve at this time were consistent with a high-grade glial neoplasm, WHO grade IV. This is a rare case of glioblastoma involving the optic nerves and suprasellar region. In such cases, molecular profiling can improve diagnosis and may provide for targeted treatments in the future.

Granular cell tumor of the neurohypophysis presenting as a third ventricle mass

Granular cell tumors of the neurohypophysis (GCT) are rare benign neoplasms belonging, along with pituicytoma and spindle cell oncocytoma, to the family of TTF1-positive low-grade neoplasms of the posterior pituitary gland. GCT usually present as a solid sellar mass, slowly growing and causing compressive symptoms over time, occasionally with suprasellar extension. They comprise polygonal monomorphous cells with abundant granular cytoplasm, which is ultrastructurally filled with lysosomes. Here we report the case of a GCT presenting as a third ventricle mass, radiologically mimicking chordoid glioma, with aberrant expression of GFAP and Annexin-A, which lends itself as an example of an integrated diagnostic approach to sellar/suprasellar and third ventricle masses.

Surgical approach to the treatment of pituicytoma. Report of five cases and a literature review

Background

Pituicytoma (PTs) is a rare tumor of the sella and suprasellar region, derived from the pituicytes of the neurohypophysis, having distinct histological characteristics of glial neoplasms. We reported, the clinical data, neuroimaging studies, surgical approaches and pathology in five patients with PTs and also, we reviewed the literature.

Methods

Retrospective chart from five consecutive patients with PTs treated at one University Hospital from 2016 to 2021 were reviewed. In addition, we conducted a search in PubMed/Medline databases using the term "Pituicytoma". Data regarding age, gender, pathological findings, and treatment modality applied were extracted.

Results

All patients were female, aged 29-63, complaining of headaches, visual loss and field defects, dizziness and normal or abnormal levels of circulating pituitary hormones. Magnetic Resonance Imaging (MRI) showed in all patients a sellar and suprasellar mass, which was removed through an endoscopic transsphenoidal approach. Our third patient had a subtotal resection followed by close observation. Histopathology showed a glial non-infiltrative tumors with spindle cells, and a final diagnosis of pituicytoma was made. After surgery, visual field defects in all patients were normalized, and in two patients normal levels of plasma hormones were restored. After a mean of three years follow-up, the patients were managed post-operatively through close clinical observation and serial MRI. None of the patients had recurrence of the disease.

Conclusion

PTs is a rare glial tumor of the sellar and suprasellar region that arises from neurohypophyseal pituicytes. Disease control may be achieved by total excision.

Pituicytoma with pleomorphism: A case report with cytological findings

Pituicytoma is a rare neoplasm, arising in the posterior pituitary or in the hypophyseal stalk, and its cytological findings have not yet been well-described. We have experienced a case of pituicytoma, which was difficult to diagnose intraoperatively, because of its cellular pleomorphism. A tumor measuring 18 mm in maximum diameter was found at the sella turcica in a Japanese woman in her forties. Both intraoperative crush cytology and histology of the resected tumor showed pleomorphic spindle or round cells, including multinucleated cells. Tumor cells were positive for TTF-1, S-100 protein, and vimentin, partially positive for glial fibrillary acidic protein and epithelial membrane antigen, and negative for synaptophysin, hormones of the anterior pituitary gland, CD34, Olig2, PAX8, and napsin A. Ki-67 labeling index was 2.0%. Tumors included in the differential diagnosis in general are pituitary adenoma, craniopharyngioma, germinoma, and metastatic tumor on the radiological standpoint, and pilocytic astrocytoma and meningioma on the cytological standpoint. However, our case was difficult to differentiate especially from high-grade glioma only by morphology, and immunohistochemistry including TTF-1 was helpful.

Endoscopic Endonasal Surgery for Uncommon Pathologies of the Sellar and Parasellar Regions

Endoscopic skull base surgery has become an integral part of the present neurosurgical armamentarium. The pioneering efforts in which the purely endoscopic transsphenoidal approach was introduced have triggered a growing tide of using the endoscopic endonasal procedures for a large variety of skull base lesions. Because of their anatomical peculiarities, lesions of the sellar and parasellar regions lend themselves very well to the endoscopic endonasal approaches. Apart from the common pathological entities, many other less frequent pathologies are encountered in the sellar and parasellar area. In this chapter, we review the surgical technique of the endoscopic endonasal transsphenoidal approach and its extensions applied to a variety of rare and uncommon pathological entities involving the sella turcica and clivus. An overview of these pathological entities is also presented and exemplified.

Surgical management of pituicytomas: a single-center case series

OBJECTIVE

Pituicytomas (PT) are rare benign sellar and/or supra sellar tumors which surgical treatment might be challenging, owing to the hypervascularity of the tumor. Here, we report our experience with PTs, describe their clinical and radiological features, and propose an optimal therapeutic strategy.

METHODS

This is a retrospective single-center study, reporting the clinical manifestations, radiological characteristics, histopathological features, treatment strategies and long-term outcomes of four patients who have been treated for a PT at Bicêtre University Hospital in Paris, France, over the past 7 years.

RESULTS

Four patients were operated mean age at presentation was 60.25 years. Main symptoms, which tended to be progressive, included visual field defects and pituitary-hypothalamic dysfunction. Radiologically, all our cases resented with sellar and suprasellar localization with cavernous invasion in 75% of cases. Endoscopic transphenoidal approach was performed as first surgery for all cases. Transcranial route was done in one case. During surgery, important bleeding was observed in all cases. Gross total resection was obtained with a single surgery in two cases and a second surgery was necessary in the two remaining cases. Pathological diagnosis was confirmed in all cases. No recurrences were noted after an average follow-up of 3.6 years.

CONCLUSIONS

PT is a rare differential diagnosis of sellar and/or parasellar tumors, whose hemorrhagic nature can become a challenge during surgery. We added four more cases to the literature to make physicians establish Piticytomas at suspicion diagnosis for sellar and/or suprasellar masses. Knowing the diagnosis, a preparation should be made preoperatively to avoid possible complications peroperatively.

Detection of Tumor-specific DNA Methylation Markers in the Blood of Patients with Pituitary Neuroendocrine Tumors

Background

DNA methylation abnormalities are pervasive in pituitary neuroendocrine tumors (PitNETs). The feasibility to detect methylome alterations in circulating cell-free DNA (cfDNA) has been reported for several central nervous system (CNS) tumors but not across PitNETs. The aim of the study was to use the liquid biopsy (LB) approach to detect PitNET-specific methylation signatures to differentiate these tumors from other sellar diseases.

Methods

We profiled the cfDNA methylome (EPIC array) of 59 serum and 41 plasma LB specimens from patients with PitNETs and other CNS diseases (sellar tumors and other pituitary non-neoplastic diseases, lower-grade gliomas, and skull-base meningiomas) or nontumor conditions, grouped as non-PitNET.

Results

Our results indicated that despite quantitative and qualitative differences between serum and plasma cfDNA composition, both sources of LB showed that patients with PitNETs presented a distinct methylome landscape compared to non-PitNETs. In addition, LB methylomes captured epigenetic features reported in PitNET tissue and provided information about cell-type composition. Using LB-derived PitNETs-specific signatures as input to develop machine-learning predictive models, we generated scores that distinguished PitNETs from non-PitNETs conditions, including sellar tumor and non-neoplastic pituitary diseases, with accuracies above ~93% in independent cohort sets.

Conclusions

Our results underpin the potential application of methylation-based LB profiling as a noninvasive approach to identify clinically relevant epigenetic markers to diagnose and potentially impact the prognostication and management of patients with PitNETs.

Malignant Endo-suprasellar Glioma: A Case Report and a Brief Review of the Literature

INTRODUCTION

Malignant sellar gliomas are very rare phenomena. To date, only few cases of sellar and suprasellar glioblastomas have been reported, most of which originate from the optic nerve or optic chiasm.

CASE PRESENTATION

We present a 34-year-old woman with malignant endo-suprasellar glioma, originating from the pituitary stalk, which was initially classified as a macroprolactinoma.

CONCLUSIONS

Although malignant sellar gliomas can mimic the clinical, endocrinological, and radiological features of pituitary macroadenomas, rapid progression without appropriate hormonal activity suggests their diagnosis. Considering the high malignant potential of sellar glioblastomas, it is important to discuss the specific features of these tumors and to investigate the possibility of differential diagnosis in the preoperative stage, which can be useful for early selection of the treatment plan.

A Rare Case of Pituicytoma Presenting Cystic Formation

Pituicytoma is a rare solid benign tumor of the sellar and/or suprasellar region originating from the pituicytes of the neurohypophysis or infundibulum, which is not differentiated from a pituitary adenoma that is diagnosed mostly in the sellar and/or suprasellar region. In addition, cystic tumors are very rare and have not been reported due to their solid and hypervascular natures. A 33-year-old man presented with a chronic headache which exacerbated recently. MRI was performed and revealed a cystic tumor in the sellar and suprasellar regions with a small parenchymal island in the cyst compressing the optic chiasm. The endoscopic endonasal transsphenoidal approach was used to remove the tumor. Immunohistochemical staining was positive for thyroid transcription factor 1, S-100 protein, and glial fibrillary acidic protein. The pituicytoma was diagnosed based on histologic findings. The authors review herein the literature on clinical presentation, diagnosis, surgical management, and outcome.

Clinical features, radiological profiles, pathological features and surgical outcomes of pituicytomas: a report of 11 cases and a pooled analysis of individual patient data

BACKGROUND

Pituicytoma is an extremely rare low-grade glial tumor that is closely related to the neurohypophysis axis. Most studies of pituicytomas include only several cases. To better understand this disease, we reviewed a series of cases of pituicytomas. The diagnosis and treatment of pituicytoma must be further elucidated.

METHODS

Eleven patients with pituicytoma admitted to Beijing Tiantan Hospital from 2012 to 2019 were selected. The clinical features, including radiological and histological examination, surgical records and prognosis were reviewed. Sixty-eight other previously published cases of pituicytoma also were used to analyze the predictive factors for the results. The Cox regression model was used for univariate and multivariate analyses.

RESULTS

Our patients included 5 males (45.5%) and 6 females (54.5%), with a mean age of 49.3 years. The tumor was located in the suprasellar region in 5 patients (45.5%), intrasellar region in 4 patients (36.4%), and intrasellar-suprasellar region in 2 patients (18.2%). All patients were misdiagnosed with other common tumors in the sellar region before the operation. During the operation, gross total resection (GTR) of the tumor was achieved in 6 patients (54.5%), and subtotal resection (STR) was achieved in 5 patients (45.5%). The mean progression-free survival (PFS) time was 29.82 months. Tumor progression after surgical resection occurred in 4 patients (36.4%). Among them, 60.0% of the patients (cases 4, 5, 7) with STR experienced progression, while 16.7% of the patients (case 2) with GTR experienced progression. Combined with the 68 cases in the literature, GTR was an independent risk factor for PFS time (P < 0.05).

CONCLUSIONS

Pituicytomas are more common in middle-aged people and the sellar region. The clinical manifestations of pituicytomas are different, but no diagnostic clinical features have been identified other than an abnormally abundant blood supply. Currently, GTR is the best approach for the treatment of pituicytomas. More patients and longer follow-up periods were needed to further elucidate the biological features of pituicytomas.

Pituicytoma: Report of three cases and a systematic literature review

Pituicytoma is a rare subtype of WHO grade I glioma that originates in the neurohypophysis or infundibulum. Here we presented 3 cases of histopathologically diagnosed pituicytoma and subsequently performed a corresponding systematic literature review. A comprehensive literature search of the PubMed database was conducted. A total of 77 studies were eventually reviewed and 168 pituicytoma cases were identified. The epidemiology, clinical manifestations, radiological features, treatment, and pathological findings of all previous pituicytoma cases were summarized, and a "portrait" of this rare tumor was shown. It is hoped that the current study will afford a broader and more adequate understanding upon this rare disease.

Posterior pituitary tumours: patient outcomes and determinants of disease recurrence or persistence

OBJECTIVE

Posterior pituitary tumours (PPTs) are rare neoplasms with the four recognised subtypes unified by thyroid transcription factor -1 (TTF-1) expression, according to the 2017 WHO classification. Though traditionally defined as low-grade neoplasms, a substantial proportion of them show recurrence/persistence following surgery.

METHODS

We selected patients with PPTs in our cohort of 1760 patients operated for pituitary tumours over the past 10 years (2010-2019). The clinical, radiological, hormonal, histopathological profiles and long-term outcomes of the three cases identified (two pituicytomas and one spindle cell oncocytoma, SCO) were analysed. Following a literature review, data of all published cases with documented TTF-1 positive pituicytomas and SCOs were analysed to determine the predictors of recurrence/persistence in these tumours.

RESULTS

Patients presented with compressive features or hypogonadism. Two had sellar-suprasellar masses. One had a purely suprasellar mass with a pre-operative radiological suspicion of pituicytoma. Two were operated by transsphenoidal surgery and one transcranially guided by neuronavigation. Histopathology confirmed spindle cells in a storiform arrangement and low Ki67 index. Immunohistochemistry showed positive TTF-1, S-100 expression and variable positivity for EMA, vimentin and GFAP. Re-evaluation showed recurrence/persistence in two patients. A literature review of recurrent/persistent pituicytoma (n = 17) and SCO (n = 9) cases revealed clinical clues (headache for pituicytomas, male gender for SCO), baseline tumour size (≥20.5 mm with sensitivity exceeding 80%) and longer follow-up duration as determinants of recurrence/persistence.

CONCLUSION

PPTs are rare sellar masses with quintessential TTF-1 positivity. Recurrent/persistent disease following surgery is determined by greater tumour size at baseline and duration of follow-up. This warrants intensive and long-term surveillance in these patients.

Primary Tumors of the Posterior Pituitary Gland: A Systematic Review of the Literature in Light of the New 2017 World Health Organization Classification of Pituitary Tumors

OBJECTIVE

The rare clinical entity of primary posterior pituitary tumors (PPTs) includes pituicytomas, granular cell tumors, spine cell oncocytomas, and sellar ependymomas. The recent World Health Organization classification of PPTs based on thyroid transcription factor 1 positivity has led to more investigations into the epidemiology, clinical presentation, nature history, histologic features, and operative characteristics of these tumors. The aim of this review is to summarize the characteristics of primary PPTs.

METHODS

Our summary involved an in-depth review of the literature on PPTs. Our systematic review was carried out using the PubMed database and PRISMA guidelines.

RESULTS

An initial search identified 282 publications. After strict application of the inclusion criteria, we found 16 articles for case series of patients with primary PPT (N > 5), which were included in our table for literature review. An additional 10 articles were review articles on PPTs published in the last 20 years and were used as resource for our systematic review. An extensive analysis was then performed to extract relevant clinical data with respect to the clinical radiologic histopathologic profile of primary PPTs and their treatment outcome.

CONCLUSIONS

Primary PPTs are a rare group of pituicyte-derived low-grade nonneuroendocrine neoplasms that arise from the sellar region. The nondescript radiographic findings and subtle endocrine abnormalities also veil their accurate diagnostic prediction. As shown through the narrative as well as the literature review, there is still a lot to be understood about PPTs. A prospective multicenter registry of these rare tumors would benefit both the neurosurgical as well as the endocrinologic knowledge base.

Intraoperative cytology of pituicytomas

BACKGROUND

Pituicytoma is a rare tumor of the sella and suprasellar region. It is common for these tumors to be misdiagnosed radiographically as pituitary adenomas, meningiomas, and craniopharyngiomas. Histologically, pituicytomas are also known to show variable morphology. These factors often complicate intraoperative consultation, especially when tissue is limited.

METHODS

A database search (January 1990-June 2019) identified 13 surgically resected pituicytomas that were sent for intraoperative consultation. The intraoperative cytology was reviewed by two pathologists, and both squash preparations/smears and touch preparations were included.

RESULTS

The cytological features of pituicytomas were variable. The cytoplasm ranged from fibrillary to fine and wispy. The nuclei were round to ovoid with occasional tumors showing spindled morphology. Small nucleoli were seen in all tumors, and chromatin was fine to vesicular. While squash preparations were cellular and revealed cohesive groups of tumor cells, touch preparations were often paucicellular with the exception of one tumor. The cytological features of pituicytomas are compared to those of other tumors with similar radiographic appearances.

CONCLUSIONS

Our findings illustrate the range of cytological features of these rare tumors and highlight the difficulty in making a definitive intraoperative diagnosis. Pituicytomas should be considered in the differential of a sellar/suprasellar lesion with glial and meningioma-like cytological features.

Primary tumors of the posterior pituitary: A systematic review

In 2017, the World Health Organization established that pituicytoma, granular cell tumor (GCT), spindle cell oncocytoma (SCO) and sellar ependymomas (SE) are posterior pituitary tumors (PPT). They probably arise from the pituicytes and may constitute a unique histopathological entity. We carried out a systematic review using PubMed's database. A total of 266 patients with pathological diagnosis of PPT (135 pituicytomas, 69 GCT, 47 SCO, 8 SE and 7 mixed histology tumors) were analyzed. Gender distribution was identical and median age at diagnosis was 48 ± 21.8 years. Main presentation symptoms were visual disorders (n = 142; 58.1%), headache (n = 99; 40.5%), hypopituitarism (n = 84; 34.4%), hypercortisolism (n = 10; 4.1%), polyuriapolydipsia (n = 6; 2.4%) and acromegaly features (n = 5; 2.0%). On MRI, 122 (47.6%) patients showed sellar with suprasellar extension masses, 67 (23.1%) were suprasellar and 63 (24.6%) exclusively sellar. Median tumor size was 22.0 ± 14.2 mm. Two hundred sixty four patients underwent surgery, transphenoidal access was selected in 132 (64.4%) and craniotomy in 58 (28.3%). Complications were hypopituitarism (n = 70; 42.1%), diabetes insipidus (n = 55; 33.1%) and hemorrhage (n = 50; 30.1%). Tumor persisted in 93 patients (45.6%) and recurred in 13 (6.4%). Regarding comparison between main types of PPT, SCO patients were diagnosed later (60.0 vs 47.0 vs 47.0 years, p = 0.023), the tumor was larger 25.0 mm [10.8] vs 20.0 mm [14.2] vs 2.0 mm [15.0] and they were frequently sellar with suprasellar extension tumors (71.7% vs 46.2% vs 32.8%, p = 0.003) compared to pituicytoma and GCT. In conclusion, PPT are rare tumors and have been misdiagnosed mainly as non-functioning pituitary adenomas. Different types of PPT share similar epidemiology, clinical manifestations and surgical outcomes. Surgery is the only curative option but complications and subtotal resection are common.

Histologic, immunohistochemical, and molecular features of pituicytomas and atypical pituicytomas

Pituicytoma is a rare, poorly characterized tumor of the sellar region that is thought to be derived from neurohypophyseal pituicytes. Resection of pituicytomas is often associated with significant morbidity including diabetes insipidus and panhypopituitarism. Most of the literature on this tumor exists as small case series or case reports. Here we describe a cohort of fourteen pituicytoma resections from eleven patients. The average follow-up on these cases is 3.7 years with some patients having over 10 years of follow-up data available in the electronic medical record. Pituicytomas were frequently misdiagnosed on pre-operative imaging, and surgical resection was associated with persistent endocrine abnormalities. Histologically, the tumors showed a range of morphologies from epithelioid to spindled. All tumors were positive for TTF-1 with variable immunostaining for other markers including GFAP, EMA, S100, SSTR2A, and synaptophysin. Within this cohort are two patients with atypical pituicytomas which showed increased cellularity, pleomorphism, mitoses and elevated Ki-67 proliferation indexes when compared to non-atypical pituicytomas. Next generation sequencing performed on three tumors revealed alterations in genes involved in the MAPK pathway. Additionally, immunohistochemical staining for phosphorylated-ERK was positive in the majority of tumors. Increased awareness of the neoplastic entity and identification of targetable mutations have the potential to decrease the morbidity associated with resection of pituicytomas.

Clinical features, diagnosis and therapy of pituicytoma: an update

BACKGROUND

Pituicytomas (PTs) are extremely rare, low-grade glial tumors closely related to the neurohypophyseal axis. Definite conclusions concerning the optimal diagnostic and therapeutic approach to these neoplasms are lacking to date, as most of this information has been presented as case reports.

METHODS

Retrospective review of case reports published in the scientific literature to date, including a new illustrative example treated in our department.

RESULTS

116 cases were collected. PTs had a higher prevalence in the fifth and sixth decades of life, with a slight male predominance. Main symptoms, which tended to be progressive, included visual field defects and pituitary-hypothalamic dysfunction. Radiologically, PTs were found anywhere along the hypothalamic-pituitary axis mimicking other, more frequent tumors growing in this anatomical region. Surgical treatment included both transcranial or transsphenoidal approaches, and resulted in gross total resection and morbidity rates of 46.8 and 59%, respectively; the latter essentially consisted in anterior and posterior pituitary dysfunction, with limited impact on daily quality of life.

CONCLUSIONS

Due to both low frequency and the absence of pathognomonic clinical and/or radiological features, formulating a suspicion diagnosis of PT represents a considerable challenge even for experienced professionals. The indication for treatment should be made on an individual basis, but it is inescapable in the presence of a visual field defect. The surgical approach has to be tailored according to the topography of the tumor and preoperative symptoms; the greatest challenges in accomplishing a gross total removal are represented by the degree of adherence and vascularization of the PT.

Posterior pituitary tumours: the spectrum of a unique entity. A clinical and histological study of a large case series

PURPOSE

In 2017, the WHO established that pituicytoma, granular cell tumour (GCT) and spindle cell oncocytoma (SCO) are posterior pituitary tumours (PPT). Recent data suggests that these tumours probably arise from the pituicytes and may constitute a spectrum of a unique histopathological entity. Our aim is to report the clinical findings and surgical outcomes of 16 patients with PPT. We also evaluated the tissue specimens available in light of current knowledge.

METHOD

Cross-sectional study with retrospective data.

RESULTS

PPT were 7 pituicytomas, 3 GCT and 6 SCO. Patients mean age was 55 years old and 75% were female. Basal hormonal study showed hyperprolactinemia (43.7%) and hypopituitarism (37.5%). There was no case of diabetes insipidus (DI). MRI showed sellar/suprasellar masses with mean size of 19.7mm. PPT was not suspected in any patient. Fifteen patients underwent surgery and complications were common: 20% had perioperative bleeding (one patient died because of a massive haemorrhage), 57.1% hypopituitarism, 35.7% permanent DI and 21.4% underwent a second surgery. Pathological findings shown positivity for thyroid transcription factor 1, vimentin and negativity for cytokeratin and chromogranin A in all specimens evaluated. S100 protein was positive in 88.8% of tumours. Ki67 was ≥ 3% in 66.6% and ranged from 4-7% in SCO.

CONCLUSION

PPT have similar histology, clinical features and are frequently misdiagnosed as nonfunctioning pituitary tumours. However, post-surgical complications including haemorrhage are common. A high clinical suspicion is needed to presume the diagnosis prior surgery and diminish the high morbidity of these tumours.

Epithelioid pituicytoma: An unusual case report

Background:

Pituicytomas are considered World Health Organization Grade I malignancies. Until September 2017, a total of 81 cases of pituicytomas were diagnosed and described in literature. We present such a case in which histopathology shows an epithelioid pattern, a rare variant of pituicytoma. As far as we know, this is only the second such case described in the literature.

Case Description:

A 61-year-old male patient presented with complaints of progressive decrease in visual acuity for about 7 months, worse on the left side. Laboratory and endocrinological investigation returned normal values. Magnetic resonance imaging revealed a mixed solid-cystic lesion, measuring about 3.1 × 2.2 × 2.9 cm. The lesion presented with intermediate signal intensity in T1 and T2 sequences and showed avid postcontrast enhancement. The patient underwent resection through a left pterional approach. Pathology revealed a glial neoplasm with an epithelioid pattern and moderate cellularity with rounded-elongated cell nuclei and with a broad eosinophilic cytoplasm. Absence of cellular pleomorphism, any mitotic figures, or areas of necrosis was noted.

Conclusion:

The epithelioid variant of pituicytomas differs from the commonly encountered forms of this tumor which typically present in a fascicular pattern. Microsurgical resection is the treatment of choice. However, in many cases, subtotal resection was performed because of a considerable risk for neurovascular injuries.

Aberrant expression of thyroid transcription factor-1 in schwannomas

Aberrant expression of thyroid transcription factor-1 (TTF-1) has been observed in tumors arising in locations other than thyroid gland, lung and ventral forebrain. However, TTF-1 expression in schwannomas has not yet been studied. Meanwhile, a few inconsistent changes in protein expression have been identified between schwannomas and other peripheral nerve sheath tumors. We evaluated TTF-1 expression in 161 schwannomas and 43 other peripheral nervous system lesions, including ganglioneuromas (n = 8), malignant peripheral nerve sheath tumors (MPNSTs) (n = 11), neurofibromas (n = 24), and traumatic neuromas (n = 9), using immunohistochemistry and verified it using quantitative real-time reverse-transcription polymerase chain reaction (qPCR) to explore TTF-1 expression in peripheral nervous system lesions. Formalin-fixed paraffin-embedded (FFPE) tissues were obtained for both analyses. In this study, we observed nuclear TTF-1 staining in 109 (67.7%) schwannomas, including 102 of 131 (77.9%) conventional, 1 of 20 (5.0%) cellular and 6 of 10 (60.0%) plexiform schwannomas. Nuclear staining was not observed in normal peripheral nerves and non-schwannoma lesions. qPCR verified the aberrant expression and revealed a correlation between TTF-1 protein and mRNA levels (r = 0.633, P = .003). In conclusion, the data from our study show that TTF-1 is selectively expressed in the majority of schwannomas, particularly the conventional variants. Based on this observation, the TTF-1 protein and mRNA are specifically expressed in schwannomas. This highly aberrant expression of varying amounts of TTF-1 may provide new clues to reveal the pathogenesis of schwannoma.

Small Cell Glioblastoma of the Sella Turcica Region: Case Report and Review of the Literature

BACKGROUND

Glioblastomas in the sellar region are very rare; in most cases, the tumor originates from the optic nerve or optic chiasm. Only 4 cases of sellar glioblastoma with a nonoptic origin have been reported. We present such a case with detailed clinical, imaging, and histopathologic information. We also review similar published cases.

CASE DESCRIPTION

A 42-year-old woman presented with endocrinologic abnormalities, including amenorrhea and lactation, symptoms of diabetes insipidus, and signs of elevated intracranial pressure. Magnetic resonance imaging showed a giant, heterogeneously enhancing lesion involving the intrasellar, parasellar, and suprasellar regions, with hypercellularity and signs of infiltration of adjacent structures. Intraoperative examination revealed the tumor to be independent from the optic pathways, but it showed infiltration of the hypothalamic region. Histopathologic examination demonstrated uniformly packed small cells and negative staining for glial fibrillary acidic protein, which was consistent with a diagnosis of small cell glioblastoma.

CONCLUSIONS

This is the first report of a small cell glioblastoma in the sella turcica region. Glioblastomas in the sellar region with no clear evidence of an optic origin should be viewed as an independent disease entity. The typical characteristics of this tumor indicate it should be considered a rare subtype of glioblastoma. Further accumulation of experience is needed to better differentiate these cases and to offer optimal treatment.

Pituicytoma-An outlook on possible targeted therapies

INTRODUCTION

Pituicytoma is a rare neoplasm of the sella region. Tumor resection is the primary treatment option, but remains subtotal due to excessive bleeding in many cases. The search for alternative or additional treatment regimens is necessary.

AIMS

We aimed to determine the receptor expression of pituicytoma to find alternatives or supplements to surgical therapy in the use of targeted therapies.

METHODS

Pituicytoma samples were collected from three institutions between 2006 and 2015 and were stained for vascular endothelial growth factors (VEGF), thyroid transcription factor (TTF1), and somatostatin receptors (SSTR 2/3/5). The stains were classified from 0=no staining to +++=strong staining. A complementary retrospective analysis of the patient charts regarding sex, age, and primary symptoms, pituitary function, and perioperative complications was performed.

RESULTS

Ten samples were analyzed; mean patient age was 57.8 years SD 16.3 years. Seven samples were acquired from male patients (one relapse) and three from female. All tumors stained strongly positive (+++) for VEGF-R. Six samples stained positive for TTF1. As for somatostatin receptors, three samples were slightly positive for SSTR 2; seven were negative. SSTR 3 was + in one, three were ++, three were +++, and three were 0. SSTR 5 stained +++ in 1, ++ in 5, + in 1, and 0 in three patients.

CONCLUSIONS

Pituicytomas were generally positive for VEGFR and showed regular expression of SSTR 3 and 5 indicating a possible treatment option through targeted therapies in cases where resection remains insufficient. Further research is necessary as to whether tumor growth can be inhibited using these pathways.

Clinical and Anatomic Features of Supraglandular Pituitary Adenomas

OBJECTIVE

Supraglandular pituitary adenoma (SGPA) is one of the extraordinary pituitary adenomas and shows different clinical and radiologic features. We retrospectively reviewed our cases of SGPAs to elucidate the radiologic, anatomic, and clinical features.

METHODS

We identified 9 patients with pathologically proven SGPA and classified them into 2 groups radiologically: either glandular or stalk types. Magnetic resonance images were correlated with intraoperative anatomic differences between the groups. Clinical and endocrinologic characteristics and surgical outcomes were reviewed.

RESULTS

The proportion of SGPAs was 1.2% of all pituitary adenomas surgically treated in our patient cohort. The glandular-type tumors (n = 7) had a thinned or defective diaphragma sellae. There was a clear plane between the tumor and pituitary stalk. For the stalk-type tumors (n = 2), the diaphragma sellae was intact and no clear border between the mass and stalk was found. Endocrinologic and immunohistochemical evaluation showed that 5 of 7 glandular-type tumors (71%) were functioning pituitary adenomas, whereas 2 stalk-type tumors were nonfunctioning. Eight of 9 patients underwent an endoscopic endonasal approach and tumor was totally removed in 7 (78%).

CONCLUSIONS

SGPAs are rare and preoperative diagnosis is possible based on their distinct radiologic, clinical, and anatomic features. SGPAs can be divided into 2 groups according to the anatomic features. The origin of tumor, whether the superior surface of the gland or the pituitary stalk, determined the location, extent, and relationship with the diaphragma sellae. The surgical outcome via an endoscopic endonasal approach was favorable.