Pituicytoma: A report of three cases and literature review

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: A rare tumor of the sella. A case report and review of literature for diagnosis and management

Background

Pituicytomas are rare tumors of the pituitary gland derived from the ependymal cells and line the pituitary stalk and posterior lobe. These tumors are located in the vulnerable regions of the brain: Either in the sellar or suprasellar area. The location marks the difference in the clinical features of the tumor. Here, we report a case of histopathologically diagnosed pituicytoma of the sellar region. Literature is also reviewed and discussed to gain a better understanding of this rare disease.

Case Description

A 24-year-old female presented to the outpatient department with complaints of headache, diplopia, dizziness, and decreased vision in the right eye for 6 months. Computed tomography scan brain without contrast showed a well-defined hyperdense lesion in the sella without associated bony erosion. Her magnetic resonance imaging showed well defined rounded lesion in the pituitary fossa which was isointense on T1-weighted image and hyperintense on T2-weighted images. A presumptive diagnosis of pituitary adenoma was made. She underwent endoscopic endonasal transsphenoidal resection of pituitary mass. Intraoperatively, normal pituitary gland was visualized and there was a grayish-green-colored, jelly like tumor which was pulled gently. On 9^th postoperative day, she presented with cerebrospinal fluid (CSF) rhinorrhea. She underwent endoscopic CSF leak repair. Her histopathology was concluded to be Pituicytoma.

Conclusion

Pituicytoma is an uncommon diagnosis. The surgical aim is to completely excise the tumor which results in complete cure, but incomplete resection may be performed due to high vascularity of this tumor. In case of incomplete excision, recurrence is common and adjuvant radiotherapy may be administered.

A rare case of pituicytoma-related hyperprolactinemia due to mass effect on infundibular stalk-Case report

INTRODUCTION AND IMPORTANCE

Pituicytomas are extremely rare cancers of the sellar and suprasellar region that appear from the infundibulum or posterior pituitary. World Health Organization in 2007, described pituicytoma as a low-grade tumour (Grade I) in the taxonomy of CNS cancers. The tumour can frequently simulate a pituitary adenoma and is also linked with hormonal disorders. Distinguishing a pituitary adenoma from a pituicytoma can be challenging. We present a rare case report where an elderly female showed high levels of prolactin mainly due to mass effects along with diagnostic, imaging, and immunohistochemical characteristics of pituicytoma.

CASE PRESENTATION

A 50-year-old female known case of hypothyroidism, complained of headache associated with dizziness and blurry vision. Her prolactin levels were high which led to the suspicion of pituitary involvement and underwent MRI. The imaging study revealed a well-defined, completely suprasellar, homogenously enhancing mass lesion arising from the left lateral aspect of the pituitary infundibulum. The initial differential diagnosis from the imaging included an ectopic pituitary gland, adenoma, pituicytoma, or hypothalamic glioma. She underwent a right supra-orbital craniotomy for debulking of the pituitary stalk lesion. The histopathological diagnosis was pituicytoma, WHO grade I.

CLINICAL DISCUSSION

The clinical manifestations are mostly depended upon the tumour mass and position. They typically present due to mass effects leading to hormonal disorders. The imaging studies are the backbone of the clinical diagnosis along with the histopathological findings. Surgical resection is the preferred treatment for pituicytoma, with an exceptionally low recurrence rate (4.3 %) following complete removal.

CONCLUSION

Pituicytomas are slow-growing, benign glial growths. It is challenging to diagnose before surgery as its clinical manifestations and imaging findings look like those of non-functional pituitary adenomas. The effective treatment for pituicytoma is gross total resection by the endoscopic method or transcranial technique.

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.

Pituicytoma: A rare case report of sellar and suprasellar tumor

Introduction

Pituicytomas are low-grade glial tumors in the sellar and suprasellar region. They may be easily confused with pituitary lesions. We review the literature in order to better understand and categorize the natural history, clinical presentations, and treatments.

Presentation of case

A 45-year-old female patient who complained of left eye blurred vision for 2 months. The imaging study revealed a solid sellar tumor with marked homogeneous enhancement following intravenous administration of gadolinium, and compression of the optic chiasm. Thus, under the preoperative diagnosis of pituitary macroadenoma, the patient underwent endoscope-assisted surgery via the transsphenoidal approach. The patient recovered well after surgery. The histopathological diagnosis was pituicytoma, WHO grade I.

Clinical discussion

Pituicytomas are defined as a circumscribed low-grade glial tumor arising from the neurohypophysis or infundibulum with bipolar spindle cells arranged in a fascicular or storiform pattern (a cartwheel). The clinical symptoms are variable depending on the tumor size and location. They usually present due to mass effect. The radiographic characteristics are not nonspecific. The diagnosis of pituicytoma is based on histopathological evidence. Pituicytomas consist of a solid proliferation of elongated spindle cells arranged in interlacing fascicles and/or in a “storiform” pattern. In immunohistochemical studies, pituicytomas was strongly expressed in TTF-1.

Conclusion

Pituicytomas are benign, slow-growing glial tumors. It is difficult to diagnosed before operation as its clinical presentations and imaging studies resemble those of non-functional pituitary adenomas. The best chance of successful treatment is gross total resection by the endoscopic approach or transcranial approach.

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Pituicytomas are rare benign tumors arising from the neurohypophysis or infundibulum.

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They are often mistaken for pituitary adenomas which have a similar clinical presentations and imaging findings.

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The diagnosis of pituicytoma is based on histopathological evidence. In immunohistochemical studies, pituicytomas was strongly expressed in TTF-1.

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Complete resection of the tumor is the main treatment for pituicytoma. The choice of surgical route used may depended on the tumor size, whether invasion to other structures has occurred, and the technique of the surgeon.

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.

Treatment and prognostic factors of pituicytoma: a single-center experience and comprehensive literature review

PURPOSE

Preoperative diagnosis of pituicytomas is difficult, and management and prognostic factors remain ambiguous. The purpose of this study was to elucidate the radiological characteristics of pituicytoma, to assess the risk factors affecting tumor progression, and to propose the optimal treatment regimen based on comprehensive analysis.

METHODS

We reviewed the clinical data of 22 patients with pituicytoma confirmed pathologically in our institution. In addition, 93 cases of pituicytoma in the previous literature were recruited. The individual data of 115 patients were analyzed to evaluate the adverse factors affecting pituicytoma progression.

RESULTS

In the combined cohort, 3 of 61 patients who underwent gross-total resection (GTR) developed recurrence (4.9%); of the 54 patients who received non-GTR, 19 progressed (35.2%). Univariate and multivariate Cox regression analysis verified male gender (HR 2.855, 95% CI 1.008-8.089; p = 0.048), TS (transsphenoidal surgery; HR 3.559, 95% CI 1.015-12.476; p = 0.047), and non-GTR (HR 4.388, 95%CI 1.240-15.521; p = 0.022) were independent unfavorable factors for pituicytoma progression. A multivariate logistic regression model verified that tumor diameter ≥ 1.85 cm (OR 4.859, 95% CI 1.335-17.691; p = 0.016) was independent adverse factors for GTR. Compared with TS, OT (open transcranial) is more likely to have postoperative complications (OR 3.185, 95% CI 1.020-9.944; p = 0.046), especially vision deterioration (OR 37.267, 95% CI 4.486-309.595; p = 0.001).

CONCLUSION

Based on our findings, GTR was advocated as an optimal treatment for pituicytomas. However, in order to avoid damage to important structures, partial resection is acceptable. After that, adjuvant radiotherapy is recommended for male patients with high Ki-67 index, and the remaining patients can be followed up closely. When the tumor recurs or progresses, it is recommended to re-operate and remove the lesion completely as far as possible. If GTR is still not possible, postoperative radiotherapy for the residual tumor is recommended.

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.

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.

Pituitary Stalk Enlargement in Adults

Pathologies involving the pituitary stalk (PS) are generally revealed by the presence of diabetes insipidus. The availability of MRI provides a major diagnostic contribution by enabling the visualization of the site of the culprit lesion, especially when it is small. However, when only an enlarged PS is found, the etiological workup may be difficult, particularly because the biopsy of the stalk is difficult, harmful and often not contributive. The pathological proof of the etiology thus needs to be obtained indirectly. The aim of this article was to provide an accurate review of the literature about PS enlargement in adults describing the differences between the numerous etiologies involved and consequent different diagnostic approaches. The etiological diagnostic procedure begins with the search for possible other lesions suggestive of histiocytosis, sarcoidosis, tuberculosis or other etiologies elsewhere in the body that could be more easily biopsied. We usually perform neck, thorax, abdomen, and pelvis CT scan; positron emission tomography scan; bone scan; or other imaging methods when we suspect generalized lesions. Measurement of serum markers such as human chorionic gonadotropin, alpha-fetoprotein, angiotensin converting enzyme, and IgG4 may also be helpful. Obviously, in the presence of an underlying carcinoma (particularly breast or bronchopulmonary), one must first consider a metastasis located in the PS. In the case of an isolated PS enlargement, simple monitoring, without histological proof, can be proposed (by repeating MRI at 3-6 months) with the hypothesis of a germinoma (particularly in a teenager or a young adult) that, by increasing in size, necessitates a biopsy. In contrast, a spontaneous diminution of the lesion is suggestive of infundibulo-neurohypophysitis. We prefer not to initiate steroid therapy to monitor the spontaneous course when a watch-and-see attitude is preferred. However, in many cases, the etiological diagnosis remains uncertain, requiring either close monitoring of the lesion or, in exceptional situations, trying to obtain definitive pathological evidence by a biopsy, which, unfortunately, is in most cases performed by the transcranial route. If a simple surveillance is chosen, it has to be very prolonged (annual surveillance). Indeed, progression of histiocytosis or germinoma may be delayed.

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.

Infectious Complications of Expanded Endoscopic Transsphenoidal Surgery: A Retrospective Cohort Analysis of 100 Cases

Objective  To identify perioperative factors that may predict postoperative cerebrospinal fluid (CSF) leak and meningitis following expanded endoscopic transsphenoidal surgery (EETS). Study Design  This is a retrospective study. This study was set at the Cedars-Sinai Medical Center, Los Angeles. A total of 78 patients who underwent EETS between January 2007 and November 2018 were participated. The main outcome measures were CSF leak and meningitis. Results  A total of 78 patients underwent a total of 100 EETS procedures; 17.9 and 10.3% of patients developed postoperative CSF leaks and meningitis, respectively. Out of eight, three patients with meningitis did not develop an observable CSF leak. The risk of developing meningitis in patients with a CSF leak was significantly higher than those without a leak, with an odds ratio (OR) of 11.48 (95% confidence interval, 2.33-56.47; p  = 0.004). Pituicytomas were significantly associated with meningitis compared with other pathologies. No other patient-specific factors were identified as risks for leak or meningitis, including method of skull base repair, sex, tumor volume, or body mass index, although there was a strong trend toward reduced CSF leak rates in patient with nasoseptal flaps used for skull base repair, compared with those without (9.5 vs. 25%). CSF protein was consistently elevated on the first CSF values obtained when meningitis was suspected. Conclusion  CSF leak and meningitis are common complications of expanded endonasal surgery No statistically significant risk factors for developing a postoperative leak other than the pathology of pituicytoma were identified, including method of skull base repair, although the use of a vascularized nasoseptal flap did trend toward a reduced CSF leak rate. CSF protein is the most sensitive marker for the presumptive diagnosis and timely treatment of meningitis.

[Pituitary gland tumors]

BACKGROUND

In this article, the most common pituitary gland tumors and the various differential diagnoses with focus on (neuro-)radiological diagnostic criteria are presented.

MATERIALS AND METHODS

An intensive, selective search of the literature in PubMed was carried out.

RESULTS

Pituitary adenomas account for approximately 10-15% of all intracranial brain tumors and are the most common tumors of the sellar region. Beyond a size of 10 mm they are called macroadenomas, under 10 mm microadenomas. They can be distinguished into hormone-active and non-active adenomas. Most of the hormone-active adenomas secrete prolactin (50%), more rarely somatotropin (10%) or corticotropin (5%). Tumors in the sellar region can arise from various tissues. Due to the anatomically complex location, local adjacent structures can be affected or compressed by the tumors. Particularly in case of suprasellar extension, visual impairment due to pressure on the optic chiasm is common. Important differential diagnoses for sellar tumors include craniopharyngiomas, meningiomas, metastases, aneurysms and Rathke cleft cysts. The task of image diagnostics is the early detection of the lesions as well as the proliferation pattern into perifocal structures. Gold standard is the thin-section, contrast-enhanced MRI examination. Dynamic contrast administration is crucial for the diagnosis of the microadenoma and the specific enhancement characteristic of some other tumors.

CONCLUSION

A highly focused imaging protocol is important for the diagnosis of sellar lesions such as pituitary tumors. The current favored modality is contrast-enhanced MRI, preferably with dynamic contrast-enhanced T1-weighted sequences. Early detection of the lesions and identification of the precise anatomical location are of great importance for diagnosis and therapy.

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.

Management of pituicytomas: a multicenter series of eight cases

PURPOSE

Pituicytomas and spindle cell oncocytomas (SCOs) are two rare neoplasms of the sellar and suprasellar region, known to be challenging as they are extremely vascular and almost always misdiagnosed, altering our surgical planning and the patients' outcomes. Also we argue that recent update concerning the pathology findings of these tumors should be more widely generalized to our practice.

METHODS

This is a retrospective multicenter study, reporting the clinical manifestations, radiological characteristics, histopathological features, treatment strategies and long-term outcomes of patients who have been treated for a Pituicytoma at various institutions in Paris, France over the past 10 years. In addition, we compared our results to the world literature in order to identify similarities concerning the radiographic diagnosis and the treatment strategies of these tumors.

RESULTS

Eight patients were operated on in four different hospitals. Misdiagnosis was constant before surgery, pituitary adenoma or craniopharyngioma being suspected. During surgery (transsphenoidal approach: six cases, transcranial approach: two cases) unusual tumors were noted, with important bleeding in most cases. Complete resection could be obtained in five patients. Pathological diagnosis was confirmed in all cases. During the follow up two recurrences occurred. One was subsequently treated with radiotherapy, the other underwent a second surgery.

CONCLUSION

Recent updates concerning the histological diagnosis of pituicytomas should be generalized to our practice in order to provide a better understanding of this rare pathology and its natural course.

Common Histologically Benign Tumors of the Brain

PURPOSE OF REVIEW

As a group, benign tumors account for the majority of primary neoplasms affecting the central nervous system (CNS). This article reviews the epidemiology, clinical presentation, neuroimaging features, and management of the most common of these tumors: meningiomas, schwannomas, and pituitary adenomas.

RECENT FINDINGS

Awareness of the most common nonmalignant tumors of the CNS and their management guidelines is important as many of these tumors are managed conservatively, with neurologists playing a primary role in both surveillance and symptom management. Knowledge of the varied neurologic consequences of these tumors allows optimizing interventions that improve quality of life in people living with these tumors without incurring treatment-related complications. Awareness of the clinical features that require surgery, radiation therapy, or chemotherapy is imperative. Finally, important discoveries in both germline and somatic mutations underlying some of these lesions have contributed to the launch of several novel drug trials for these tumors.

SUMMARY

As a group, nonmalignant neoplasms are the most common neoplasms affecting the CNS in adults. Because of their unique neuroanatomic location or containment within the bony skull, these histologically benign lesions can cause significant neurologic morbidity. Management with a multidisciplinary team that includes neurologists, neuro-oncologists, radiologists, neurosurgeons, radiation oncologists, otolaryngologists, pathologists, neuropsychologists, physiatrists, and others is necessary for the optimal management of these lesions.

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.

An exceptional presentation of pituicytoma apoplexy: A case report

Pituicytomas are a rare form of indolent neoplasms, which typically present with visual disturbance and hypopituitarism. Complete resection by a trans-sphenoidal approach is the optimal treatment. Only 80 cases have been described thus far in the current literature and the present case is the first to describe the development of pituitary apoplexy in the context of a pituicytoma. A 77-year-old man presented with fatigue and clinical signs of hypogonadism and a sellar lesion was diagnosed at cerebral magnetic resonance imaging (MRI). A watch-and-wait management was initially decided and 1 year after the initial diagnosis, he presented with a thunderclap headache with images suggestive of pituitary apoplexy. A pituitary adenoma was suspected and an endoscopic resection was decided upon the development of a visual deficit. Pathological analysis established the correct diagnosis of a pituicytoma. Pituicytomas are characterised by dense vascularisation, thus ischaemic and haemorrhagic events may be common. When confronted with a hypervascularised pituitary lesion demonstrating strong contrast enhancement and no abnormal hormonal secretion, one must maintain a high index of suspicion for a pituicytoma. A wide range of differential diagnoses should thus be considered in the context of pituitary apoplexy.

Non-adenomatous pituitary tumours mimicking functioning pituitary adenomas

Objective: Pituicytomas and granular cell tumours (GCTs) of the neurohypophysis are considered non-adenomatous neoplasms in the sellar region. The association between hormone hypersecretion and the tumours is seldom discussed and unclear. Therefore, we attempt to investigate this association based on our experience and a review of the literature.Methods: We report three patients who presented with Cushing's syndrome- or acromegaly-like symptoms at our institution. They underwent transsphenoidal surgery for suspected pituitary adenomas, which were subsequently diagnosed as pituicytomas or hypophyseal GCTs following histological and immunohistochemical analysis. We also review previously reported relevant cases of pituitary non-adenomatous tumours in the literature.Results: Four cases of Cushing's syndrome with pituicytoma and one case of acromegaly with a GCT have recently been reported. In the three cases presented here, one patient with Cushing's syndrome and one patient with acromegaly also had a pituicytoma, while the second patient with acromegaly had a GCT.Conclusions: Rather than mere coexistence of non-adenomatous pituitary tumours with hypersecretory adenomas or hyperplasia, alternative causes for the observed symptoms maybe the presence of some unidentified substances produced by the tumours that stimulate the adenohypophysis to secrete pituitary hormones. The glial cells of the pituitary gland may play an important role in oncogenic differentiation and regulation of the release of hormones. Therefore, attention should be focused on investigating the origin and functions of glial cells.

Welcoming the new WHO classification of pituitary tumors 2017: revolution in TTF-1-positive posterior pituitary tumors

The fourth edition of the World Health Organization classification of endocrine tumors (EN-WHO2017) was released in 2017. In this new edition, changes in the classification of non-neuroendocrine tumors are proposed particularly in tumors arising in the posterior pituitary. These tumors are a distinct group of low-grade neoplasms of the sellar region that express thyroid transcription factor-1, and include pituicytoma, granular cell tumor of the sellar region, spindle cell oncocytoma, and sellar ependymoma. This short review focuses on the classification of posterior pituitary tumors newly proposed in EN-WHO2017, and controversies in their pathological differential diagnosis are discussed based on recent cases.