Pituicytoma: Report of Two Cases and Clues Regarding Histogenesis

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.

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.

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.

A Comprehensive Study of Spindle Cell Oncocytoma of the Pituitary Gland: Series of 6 Cases and Meta-Analysis of 85 Cases

OBJECTIVE

To discuss optimal treatment strategy for spindle cell oncocytoma (SCO) of the pituitary gland.

METHODS

Institutional cases were retrospectively reviewed. A systematic literature search and subsequent quantitative synthesis were performed for further analysis. The detailed features were summarized and the tumor control rate (TCR) was calculated.

RESULTS

Eighty-five patients (6 institutional and 79 literature) were included. The annual incidence was approximately 0.01-0.03/100,000. The mean age was 56 years. Vision loss was present in 60%. Seventy-three percent showed hormonal abnormalities. On magnetic resonance imaging, tumor was avidly enhancing, and the normal gland was commonly displaced anterosuperiorly. Evidence of hypervascularity was seen in 77%. Gross total resection (GTR) was achieved in only 24% because of its hypervascular, fibrous, and adhesive nature. The mean postoperative follow-up was 3.3 years for institutional cases and 2.3 years for the integrated cohort. The TCR was significantly better after GTR (5-year TCR, 75%; P = 0.012) and marginally better after non-GTR + upfront radiotherapy (5-year TCR, 76%; P = 0.103) than after non-GTR alone (5-year TCR, 24%). The TCRs for those with low Ki-67 index (≤5%) were marginally better than those with higher Ki-67 index (5-year rate, 57% vs. 23%; P = 0.110).

CONCLUSIONS

Frequent endocrine-related symptoms, hypervascular signs, and anterosuperior displacement of the gland support preoperative diagnosis of SCO. GTR seems to have better long-term tumor control, whereas the fibrous, hypervascular, and adhesive nature of SCO makes it difficult to achieve GTR. In patients with non-GTR, radiotherapy may help decrease tumor progression.

Adenohypophyseal hyperfunction syndromes and posterior pituitary tumors: prevalence, clinical characteristics, and pathophysiological mechanisms

Posterior pituitary tumors are rare nonneuroendocrine neoplasms originating in the neurohypophysis that lack hormonal secretory capacity. Surprisingly, these tumors are relatively frequently associated with adenohypophyseal syndromes of hormonal hypersecretion such as Cushing's disease and acromegaly. Fifteen cases of posterior pituitary tumor associated with hypercortisolism have been reported to date, 13 of them were pituicytomas (Pi) and 2 were granular cell tumors (GCT). Six patients with posterior pituitary tumor associated with acromegaly have been reported (4 Pi and 2 GCT). The main forms of clinical presentation and the possible pathophysiological mechanisms of this association are reviewed.

A rare case report of pituicytoma with biphasic pattern and admixed with scattered Herring bodies

BACKGROUND

Pituicytoma is a rare pituitary non-neuroendocrine tumour. The awareness of pituitary non-neuroendocrine tumours has gradually increased over the past several decades, but the knowledge of some histological variants of the tumours is limited, particularly in clinicopathological significance. Here, we report a rare case of pituicytoma variant.

CASE PRESENTATION

A 71-year-old man presented with sudden symptoms of stroke including urinary incontinence, weakness in right lower limb, and trouble speaking. Physical examinations showed a right facial paralysis. The radiological examinations eventually found a 1.7 × 1.4 × 1.3 cm sellar occupied lesion. After symptomatic treatment improved the symptoms, the patient underwent transsphenoidal resection of the pituitary mass. Histologically, the tumour contained hypocellular area and hypercellular area. The hypocellular area showed elongated spindle cells arranged in a fascicular pattern around small vessels and scattered Herring bodies; the hypercellular area showed a large number of pseudorosettes. Immunohistochemistrically, the tumour cells were positive for thyroid transcription factor-1, S100, and neuron-specific enolase. Neurofilament only showed a little positive in the hypocellular area, and silver impregnation was only noted in a perivascular distribution. The patient had no recurrence 4 months after the surgery.

CONCLUSIONS

The rare variant of pituicytoma has a favourable prognosis. Moreover, it needs to be distinguished pituicytomas with pseudorosettes from ependymomas because of different prognosis. Lastly, Herring bodies may occasionally be seen in the pituicytoma, which could be a potential diagnostic pitfall.

The coexistence of infundibular pituicytoma and Cushing's disease due to pituitary adenoma: A case report

OBJECTIVES

Pituicytomas are rare, solid, well-circumscribed, low grade (grade I), non-neuroendocrine, and noninfiltrative tumors of the neurohypophysis or infundibulum, which appear in the sellar/suprasellar regions. Herein, we present a case with Cushing's disease (CD) caused by an ACTH-secreting pituitary adenoma in association with an infundibular pituicytoma. Subject and Results. A 37-year-old male patient presented to the hospital with a six-month history of blurry vision. Physical examination demonstrated plethora, excessive sweating, weight gain, moon facies, and acne. Basal serum cortisol and ACTH levels were 16 µg/dl and 32 pg/ml, respectively. The results of screening tests were suggestive of Cushing syndrome. It was also 1.97 µg/dl following 8 mg dexamethasone suppression test which was consistent with CD. Pituitary MR imaging revealed a single lesion measuring 6x6.5 mm on the pituitary stalk. Infundibular mass excision and pituitary exploration by extended endoscopic endonasal approach were applied. On immunohistochemistry, strong diffuse immunolabeling for both S100 and TTF-1 was noted for the cells of infundibular mass, diagnosed as pituicytoma. Because the developed panhypopituitarism postoperatively, patient was discharged with daily desmopressin, levothyroxine, hydrocortisone, and intramuscular testosterone, once a month.

CONCLUSIONS

Pituicytoma is an uncommon noninvasive tumor of the sellar and suprasellar regions. In this case report, we described a patient with Cushing's disease to whom MRI displayed only an infundibular well-circumscribed lesion, but not any pituitary adenoma. Despite the absence of any sellar lesion, awareness of other undetected possible lesion and exploring hypophysis during the transsphenoidal surgery is mandatory for the correct diagnosis.

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.

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.

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.

Recurrent Pituicytoma with Pseudoaneurysm: Report of a Challenging Case

BACKGROUND

Pituicytoma is a rare tumor originating from glial cells of the adult neurohypophysis and infundibulum. Surgical removal is the treatment of choice for this neoplasm. In recent years the endoscopic endonasal approach has proven to be a viable and effective alternative to standard craniotomy.

CASE DESCRIPTION

We report a case of a patient submitted to surgical treatment for a recurrence of pituicytoma, which was operated on transcranially at another hospital approximately 5 years previously. After transcranial surgery, the patient developed a symptomatic recurrence and an undisclosed intrasellar pseudoaneurysm that were treated with an endoscopic endonasal approach, but still required an intracranial approach to complete the resection.

CONCLUSIONS

An intrasellar pseudoaneurysm can endanger the endoscopic removal of the pituicytoma, forcing the surgeon to reevaluate a microscopic transcranial approach or to consider a staged procedure.

Novel aspects in histopathology of the pituitary gland

The sellar and parasellar region is a complex anatomical area in which several diseases may develop. The pituitary gland may be affected by a wide range of conditions having similar clinical characteristics. Diagnosis of these lesions requires a multidisciplinary approach including, in addition to clinical, laboratory, imaging, and surgical findings, histological diagnosis of pituitary adenomas to guide therapeutic management. As the result of development in recent years of new immunohistochemical techniques, histopathological classification has become more complex and wide, and not only continues to be the gold standard in diagnosis, but also has prognostic implications. The aim of this review is to provide a clear and simple update of the main concepts of histological diagnosis of the most common pituitary conditions, especially for professionals in direct contact with such diseases.

Novel aspects in histopathology of the pituitary gland

The sellar and parasellar region is a complex anatomical area in which several diseases may develop. The pituitary gland may be affected by a wide range of conditions having similar clinical characteristics. Diagnosis of these lesions requires a multidisciplinary approach including, in addition to clinical, laboratory, imaging, and surgical findings, histological diagnosis of pituitary adenomas to guide therapeutic management. As the result of development in recent years of new immunohistochemical techniques, histopathological classification has become more complex and wide, and not only continues to be the gold standard in diagnosis, but also has prognostic implications. The aim of this review is to provide a clear and simple update of the main concepts of histological diagnosis of the most common pituitary conditions, especially for professionals in direct contact with such diseases.

Malignant adenohypophysis spindle cell oncocytoma with repeating recurrences and a high Ki-67 index

Adenohypophysis spindle cell oncocytoma (ASCO) is a rare tumor recently reported by Roncaroli et al in 2002. This tumor is considered a grade I tumor by the World Health Organization.We report a rare case of malignant ASCO with repeating recurrences and a high Ki-67 index-a challenging diagnosis guided by clinical presentations, radiological signs, and postoperative pathological tests.We represent a 30-year-old man who had suffered from headaches, diplopia, and impaired visual field and acuity. His magnetic resonance imaging revealed an abnormal sellar mass and was originally misdiagnosed as a pituitary macroadenoma. We present detailed analysis of the patient's disease course and review relevant literature.When surgically treated, the specimen revealed a typical histopathology pattern of ASCO. The tumor recurred for several times and the patient underwent 3 surgeries and 1 γ-knife treatment, which was accompanied by a continuously increasing Ki-67 index.This is the first reported case of malignant ASCO (WHO III-IV grade). Despite its rarity, ASCO should be considered in the differential diagnosis of sellar lesions that mimic pituitary adenomas.

Pituicytoma: A report of three cases and literature review

Pituicytoma is a rare tumor of the sellar and suprasellar regions, arising from the pituicytes, which are specialized glial cells in the neurohypophysis and infundibulum. Due to its rarity, ambiguity persists over the diagnosis, management and prognosis of pituicytoma. The current study presents a case series of three patients, each with a histopathological diagnosis of pituicytoma. A summary of the clinical manifestations, radiological characteristics, histopathological features, treatment strategies and prognoses are presented. In addition, 78 cases of pituicytoma, identified in a search of the published literature in Pubmed, are profiled. Pituicytoma typically presents with dysfunction of the optic nerve and pituitary. The radiological characteristics are nonspecific; diagnosis is typically made on the basis of histopathological results. The tumor is slow growing and benign and is amenable to surgical treatment by gross total resection; subsequent tumor recurrence is rare. A definitive assessment of prognosis requires an extended follow-up in a larger cohort.

Pituicytoma and Cushing's Disease in a 7-Year-Old Girl: A Mere Coincidence?

Pituicytoma is a tumor extremely rare in childhood, with only 4 cases reported in literature. It is thought to arise from the specialized glial elements called "pituicytes." The association of pituicytoma and Cushing's disease (CD) has been described only once so far, in an adult patient. A 7-year-old girl was referred for clinical signs of hypercortisolism, and a diagnosis of CD was made. MRI revealed 2 pathologic areas in the pituitary gland. The patient underwent surgery, with microscopic transsphenoidal approach, and a well-circumscribed area of pathologic tissue was identified and removed. Surprisingly, histologic and immunohistochemical study provided unequivocal evidence of pituicytoma. No pituitary adenoma could be identified. For persistent hypercortisolism, the patient necessitated transsphenoidal endoscopic reintervention and 2 other lesions were removed. By immunohistological examination, these lesions were confirmed to be corticotropin-secreting adenoma. Unfortunately, there was no postoperative decrease in corticotropin and cortisol levels, and the patient underwent bilateral laparoscopic adrenalectomy. Considering that we report a second case of association of pituicytoma and corticotropin-secreting adenoma, that CD is infrequent, and pituicytoma is extremely rare in childhood, the coexistence of these 2 tumors should not be considered a mere coincidence. To date, there is no conclusive evidence about the origin of these different subtypes of pituitary tumors. This case supports the hypothesis that these tumors share a common progenitor cell, which could be the folliculostellate cell.

Pituitary image: pituicytoma

INTRODUCTION

Pituicytoma is a rare tumor arising from the neurohypophysis or pars intermedia of the adenohypophysis.

CASE REPORT

A 36 year old male came to our observation presenting polydipsia, polyuria, polyphagia, decreased libido and altered sleep-wake rhythm. The biochemical tests showed hypotonic urine, mild hyperprolactinemia, hypogonadotropic hypogonadism, central hypothyroidism. Magnetic resonance revealed an expansive lesion of the suprasellar region (slightly isointense on T1, hyperintense on T2, impregnating contrast medium), that was partially removed by trans-cranial neurosurgical approach. The histopathological diagnosis was pituicytoma. After surgery, in addition to endocrine disorders, the patient presented severe neurological sequelae and hyperthermia, likely due to damage of the hypothalamus, followed by a progressive metabolic syndrome. The residual tumor was monitored by MRI, and, due to the early gradual increase in volume, was treated by stereotactic radiosurgery.

DISCUSSION/CONCLUSIONS

Pituicytomas are often difficult to distinguish from other hypothalamic or pituitary lesions. However, their identification would be preferable in a pre-operative setting in order to optimize the work-up and to initiate a proactive management of the expected complications.

Second-stage transsphenoidal approach (TSA) for highly vascular pituicytomas in children

INTRODUCTION

A pituicytoma in the sellar area is extremely rare in children and, due to its highly vascularized nature, can be difficult to address using the transsphenoid approach (TSA) to surgery. Here, we report a rare case of a pituicytoma that was completely removed from a child through a staged operation using the TSA. A 13-year-old girl was admitted with a 1-year history of visual disturbance and amenorrhea. Visual field examination showed left total blindness and right temporal hemianopsia. Laboratory results revealed hormonal levels all within normal ranges. Brain magnetic resonance imaging (MRI) showed a homogeneous, highly enhancing sellar and suprasellar mass, typically suggestive of a pituitary adenoma. TSA surgery revealed the tumor had a rubbery-firm consistency, hypervascularity, and profuse bleeding. We removed the tumor partially and planned a second-stage operation.

DISCUSSION

Gross total removal is the treatment of choice for this type of tumor. Attempted resection of these presumed adenomas or meningiomas using the TSA often results in unexpectedly heavy intraoperative bleeding due to the high vascularity of this rare tumor, making surgery challenging, especially in children where the tumor is within a relatively narrow corridor. While pituicytomas are a rare differential diagnosis for sellar or parasellar tumors in children, total removal by second-stage TSA surgery is indicated in the case of profuse bleeding or uncertainty of biopsy. Following first-stage TSA surgery and pathologic confirmation of pituicytoma, the strategy is typically gross total removal during second-stage TSA surgery.

CONCLUSIONS

Although very rare in children, a pituicytoma should be included in the differential diagnosis of a mass in the sellar area if the tumor is highly enhancing or very vascular. Second-stage TSA surgery is another strategy when the pathology is not clear during the first-stage TSA surgery.

Pituicytomas and spindle cell oncocytomas: modern case series from the University of California, San Francisco

PURPOSE

Pituicytomas and spindle cell oncocytomas (SCOs) are extremely rare neoplasms of the sellar and suprasellar region that can often mimic pituitary adenomas. To date, there are relatively few cases of pituicytomas and SCOs reported; and most of these are small case series.

METHODS

In this paper, we provide a retrospective review of the treatment, imaging characteristics, post-operative course, and histopathology of five cases of pituicytomas and two SCOs treated at the University of California, San Francisco (UCSF) over a 10-year period from 2003 to 2013.

RESULTS

We find that pituicytomas and SCOs present similarly to pituitary adenomas, and look identical on CT or MR imaging. We histopathologically confirmed all pituicytomas with a combination of hematoxylin and eosin morphology and immunohistochemical positivity for vimentin and S100; SCOs stain for anti-mitochondrial antigen and endothelial membrane antigen. We observe positive thyroid transcription factor 1 (TTF1) immunohistochemistry in both cases of SCO, as well as in both of the cases of pituicytoma in which TTF1 staining was available.

CONCLUSIONS

This represents the largest single-institution case series of pituicytomas and SCOs to date, and also includes the first description of the management of a pregnant female with SCO. Our findings are consistent with the idea of common histogenesis for pituicytomas and SCOs, and also raise the possibility of more aggressive growth in SCOs as compared to pituicytomas.

Surgical management of pituicytomas: case series and comprehensive literature review

OBJECTIVE

Pituicytomas are rare neoplasms that typically present as solid, noninfiltrative tumors occupying the sella and/or suprasellar space for which there is no consensus on optimal surgical management. We aimed to define a preferred surgical strategy for these tumors based on our clinical experience and comprehensive review of the world literature.

DESIGN

Case series and review of the literature.

METHODS

We documented the clinical, radiographic, and surgical findings of three patients with pituicytoma treated at our institution, as well as complications and long-term outcomes. A comprehensive review of the medical literature identified all cases of pituicytoma for which data regarding surgical approach, outcome and complications could be extracted. We compared our results with published data.

RESULTS

All three cases at our institution achieved gross total removal. Two patients underwent an expanded endoscopic endonasal transsphenoidal and transplanum (EETS-TP) approach, while one tumor was removed via craniotomy. Post-operatively all patients developed pan-hypopitutarism. The patient undergoing craniotomy suffered profound visual loss but no other neurological complications were noted. A literature review identified 67 reported cases of pituicytoma. Surgical data was available in 60 cases. Surgical approach was documented in 57 patients. Sixty-three surgeries were performed in which approach and extent of resection was available. Gross total removal was obtained in 33 % of craniotomies, 42 % of transsphenoidal procedures, and 100 % of expanded transsphenoidal procedures. Neurological complications including visual loss, hemiparesis and cranial nerve palsies were reported after craniotomy, but not after transsphenoidal approaches. Overall EETS-TP approaches were associated with the highest rate of gross total removal and no visual or neurological complications.

CONCLUSIONS

EETS-TP surgery is the preferred strategy for surgical removal of pituicytoma. EETS-TP and transsphenoidal approaches are associated with higher rates of gross total removal and lower rates of neurological complications than craniotomy. Gross total removal should be the intended goal of surgery.

Pituitary adenoma with gangliocytoma: Report of two cases

Worldwide, cases of pituitary adenoma with gangliocytoma are rarely reported. The current study reports the cases of two 47-year-old females who presented with masses in the sellar region following a general examination and radiological imaging. The two patients underwent sellar region tumor resection via the trans-naso-sphenoid approach. The histopathological examination confirmed the diagnosis of a hormone-free pituitary adenoma with gangliocytoma. The two patients were in good condition and experienced no specific discomfort subsequent to the follow-up after surgery. Gangliocytoma is a slowly growing and non-metastasizing tumor. A biopsy is required to differentiate a gangliocytoma from a malignant neuroblastoma, and excision is usually curative.

Pituicytoma with gelsolin amyloid deposition

Pituicytoma is a rare low-grade (WHO grade I) sellar region glioma. Among sellar tumors, pituitary adenomas, mainly prolactinomas, may show amyloid deposits. Gelsolin is a ubiquitous calcium-dependent protein that regulates actin filament dynamics. Two known gene point mutations result in gelsolin amyloid deposition, a characteristic feature of a rare type of familial amyloid polyneuropathy (FAP), the Finnish-type FAP, or hereditary gelsolin amyloidosis (HGA). HGA is an autosomal-dominant systemic amyloidosis, characterized by slowly progressive neurological deterioration with corneal lattice dystrophy, cranial neuropathy, and cutis laxa. A unique case of pituicytoma with marked gelsolin amyloid deposition in a 67-year-old Chinese woman is described. MRI revealed a 2.6-cm well-circumscribed, uniformly contrast-enhancing solid sellar mass with suprasellar extension. Histologically, the lesion was characterized by solid sheets and fascicles of spindle cells with slightly fibrillary cytoplasm and oval nuclei with pinpoint nucleoli. Surrounding brain parenchyma showed marked reactive piloid gliosis. Remarkably, conspicuous amyloid deposits were identified as pink homogeneous spherules on light microscopy that showed apple-green birefringence on Congo red with polarization. Mass spectrometric-based proteomic analysis identified the amyloid as gelsolin type. Immunohistochemically, diffuse reactivity to S100 protein and TTF1, focal reactivity for GFAP, and no reactivity to EMA, synaptophysin, and chromogranin were observed. HGA-related mutations were not identified in the tumor. No recurrence was noted 14 months after surgery. To the knowledge of the authors, amyloid deposition in pituicytoma or tumor-associated gelsolin amyloidosis has not been previously described. This novel finding expands the spectrum of sellar tumors that may be associated with amyloid deposition.

Update on hypophysitis and TTF-1 expressing sellar region masses

This article reviews recent literature on sellar region masses that most closely mimic nonsecretory pituitary adenomas: hypophysitis, pituicytoma, spindle cell oncocytoma, and granular cell tumor of neurohypophysis. Even today, these four entities often cannot be confidently distinguished from each other clinically or by preoperative neuroimaging features. Thus, they often come to biopsy/surgical resection and require tissue confirmation of diagnosis. Causes of secondary and primary hypophysitis will be discussed, including two newly described types, IgG4 plasma cell hypophysitis and hypophysitis caused by anti-cytotoxic T-lymphocyte antigen 4 antibody therapy for cancer. For the neoplastic conditions, emphasis will be placed on literature that has emerged since these entities were first codified in the 2007 World Health Organization fascicle. The finding that immunohistochemical staining for thyroid transcription factor-1 is shared by pituicytoma, spindle cell oncocytoma, and granular cell tumor of neurohypophysis suggests common lineage and explains why histological overlap can be encountered. We incorporate our own experiences over the last 30 years from two referral institutions with specialty practices in pituitary region masses.

Rare infundibular tumors: clinical presentation, imaging findings, and the role of endoscopic endonasal surgery in their management

Background The spectrum of infundibular lesions is broad and distinct from sellar pathologies. In many cases, histology is needed to establish the correct diagnosis and determine the treatment approach. Methods Medical files of eight patients with distinct infundibular tumors were reviewed. Histopathologically confirmed diagnosis included three pituicytomas, three granular cell tumors, and two pilocytic astrocytomas. Results Patients shared similar imaging findings and clinical symptoms, including visual impairment (n = 5), hypopituitarism (n = 4), and headache (n = 4); one patient presented with disseminated disease and symptoms from spinal metastases. All the pituicytomas, two granular cell tumors, and one infundibular pilocytic astrocytoma case underwent endoscopic endonasal surgery; gross total resection was achieved in five patients, three developed postoperative diabetes insipidus, and two developed hypopituitarism. No recurrences were observed. One granular cell tumor patient was treated with gamma-knife radiosurgery after stereotactic biopsy; the tumor remained stable in size for over 9 years. The infundibular pilocytic astrocytoma patient who presented with spinal metastases received radiotherapy and systemic chemotherapy. The overall mean follow-up period was 25.1 months. Conclusion Infundibular tumors are rare entities that represent a diagnostic challenge. Histopathological examination is essential for definitive diagnosis. Surgery, radiation therapy, and chemotherapy all have a role in the management of these tumors.

40-year old female with a sellar mass

Pituicytoma is a rare, low-grade neoplasm that originates in the neurohypophysis of the pituitary gland. We report the clinicopathologic features of a pituicytoma arising in a 40-year-old female who presented with menstrual disorder for 2 months, clinically suggestive of a pituitary microadenoma. The tumor was marked by a proliferation of elongated cells arranged in bundles and interlacing fascicles. The tumor demonstrated positive staining with S-100 protein and patchy staining for glial fibrillary acid protein and Epithelial Membrane Antigen. The tumor did not stain with antibodies to Progesterone receptor and Neu-n. An MIB-1 labeling was lower than 1%. The tumor was subtotally resected and didn’t recur after the initial surgery.

Neuroimaging characteristics and growth pattern on magnetic resonance imaging in a 52-year-old man presenting with pituicytoma: a case report

INTRODUCTION

Pituicytoma is a rare neoplasm of the neurohypophysis. To the best of our knowledge there have been no reports of pituicytoma in which long-term magnetic resonance imaging observation was performed. We calculated the doubling time of the tumor volume and described the growth pattern of a pituicytoma.

CASE PRESENTATION

A 52-year-old Japanese man with a history of decreased libido was found to have a sellar and suprasellar mass. He underwent transsphenoidal surgery, but only a small specimen was obtained because of intraoperative bleeding. The tentative histological diagnosis was schwannoma. He noticed bitemporal hemianopsia 7 years later. A follow-up magnetic resonance imaging disclosed a tumor volume doubling time of 3830 days. Transcranial gross-total tumor resection was performed. The lesion consisted of elongated and plump tumor cells that were arranged in a fascicular or storiform pattern and were positive for S-100 protein and focally positive for glial fibrillary acidic protein. The final histological diagnosis was pituicytoma.

CONCLUSION

Pituicytoma is a slow-growing tumor, but the growth rate may change during follow-up.

Pituicytoma: overview of treatment strategies and outcome

The pituicytoma is an extremely rare and little-studied primary tumour of the adult neurohypophysis. With total resection, the pituicytoma appears to have a good prognosis. However, its highly vascular nature makes total resection difficult and local recurrence after subtotal resection is not uncommon. To date, only 40 cases of pituicytoma have been reported in literature. In addition to our own case of a suprasellar pituicytoma, we are reviewing and discussing these with particular attention paid on the surgical management and outcome of this rare neoplasm.

Decreased vision and junctional scotoma from pituicytoma

Pituicytomas are rare neoplasms of the sellar region. We report a case of vision loss and a junctional scotoma in a 43-year-old woman caused by compression of the optic chiasm by a pituitary tumor. The morphological and immunohistochemical characteristics of the tumor were consistent with the diagnosis of pituicytoma. The tumor was debulked surgically, and the patient's vision improved.

Pituicytomas: radiological findings, clinical behavior and surgical management

BACKGROUND

Pituicytomas are rare low-grade glial neoplasms originating in the neurohypophysis or infundibulum that appear as solid, noninfiltrative masses occupying the sella turcica, the suprasellar space or both. Due to their high tendency to bleed and the possible firmness and adhesion to surrounding structures, preoperative diagnosis of pituicytoma is a goal for the surgeon, but it is actually a challenge because of the absence of distinctive clinical or neuroradiological findings.

METHODS

We report the new cases of three patients who underwent transsphenoidal surgery for suspected pituitary adenomas, which were determined to be pituicytomas at histological and immunohistochemical analysis. We also review previously reported cases of pituicytoma in the literature.

RESULTS

To date, 51 cases of pituicytoma have been reported in addition to our own cases. The natural history and clinical characteristics of this rare tumor are outlined.

CONCLUSIONS

Macroscopic aspects are variable, and final diagnosis is made from the typical histological and immunohistochemical pattern. The therapy of choice is gross total surgical resection since subtotal removal can lead to local regrowth, but the time to recurrence is unpredictable and highly variable. The role of adjuvant therapy is currently undefined.

Rare Tumors of the Sellar Region

Context

The sellar/ parasellar region is the location for a vast array of neoplastic and nonneoplastic intracranial space-occupying lesions. While several common lesions arising in this location have been well-described in the literature, there are rare and challenging tumors that may also arise in this region.

Objective

We focus this review on five rare tumors reported to arise in the sellar region, including spindle cell oncocytoma of the adenohypophysis, pituicytoma, intravascular papillary endothelial hyperplasia, epithelioid hemangioendothelioma and xanthogranuloma. We review their clinical presentation, histologic features, differential diagnosis and outcomes for these tumors.

Data sources

All medical literature pertaining to these entities that was searchable on PubMed was comprehensively reviewed.

Conclusions

Spindle cell oncocytoma and pituicytoma have recently been included in the 2007 edition of the World Health Organization classification of tumours of the CNS, while intravascular papillary endothelial hyperplasia, epithelioid hemangioendothelioma and xanthogranuloma have only rarely been described in this region. Knowledge of these may help prevent possible diagnostic pitfalls during postmortem evaluation.

Epithelioid pituicytoma

BACKGROUND

Pituicytomas are rare tumors of the sellar region that are derived from specialized glial cells called pituicytes. They characteristically exhibit spindle-cell features and fascicular or storiform patterns of growth. No other histological variants of this tumor have been described.

CASE DESCRIPTION

Here we report a diagnostically challenging case of pituicytoma in a 42-year-old man with a sellar mass arising from the pituitary stalk. On histological examination, the tumor displayed an epithelioid histoarchitecture with no characteristic spindle-cell or fascicular growth features. Strong immunopositivity for the pituicyte marker thyroid transcription factor-1 within tumor cells proved essential for diagnosing this unusual pituicytoma variant.

CONCLUSION

Pituicytomas may display epithelioid rather than fascicular or storiform histoarchitecture. Epithelioid pituicytoma variants may be diagnosed in cases such as ours in which both the clinical findings and immunohistochemical analysis suggest a tumor derived from pituicytes.

Pituicytoma, spindle cell oncocytoma, and granular cell tumor: clarification and meta-analysis of the world literature since 1893

BACKGROUND AND PURPOSE

Pituicytoma, SCO, and GCT are poorly understood entities with confusing nomenclature and undetermined imaging characteristics. Our purpose was to confirm published cases of pituicytoma, SCO, and GCT with the newest 2007 World Health Organization criteria and elucidate imaging findings that distinguish these tumors from common entities such as pituitary adenoma.

MATERIALS AND METHODS

A literature search identified 145 published cases (81 GCTs, 48 pituicytomas, and 16 SCOs). Case diagnoses were blindly reviewed by a neuropathologist according to the latest WHO criteria, resulting in 112 pathologically documented cases (64 GCTs, 35 pituicytomas, and 13 SCOs). Imaging illustrations from proved cases were reviewed to determine location, configuration, attenuation and signal intensity, and enhancement characteristics.

RESULTS

Only pituicytomas presented as purely intrasellar lesions (7/33). Most GCTs were purely suprasellar (28/45). All SCOs were both intra- and suprasellar (13/13). Twenty-five percent of pituicytomas (6/22) and GCTs (7/30) appeared separate from the pituitary gland. All SCOs were infiltrating. Seventy-nine percent of entities appeared isointense to brain on T1-weighted image (34/43). Seventy-four percent of pituicytomas enhanced homogeneously (14/19). Twelve of 23 GCTs and 5/7 SCOs enhanced heterogeneously. Most GCTs were hyperattenuated to brain on CT (18/20). Eleven of 13 cases enhanced homogeneously. Visual disturbances were common symptoms for all entities (67/112). Diabetes insipidus was rare (4/112).

CONCLUSIONS

Pituicytoma may be considered for purely intrasellar masses that are clearly separate from the pituitary gland. GCT should receive consideration for purely suprasellar lesions that are hyperattenuated to brain on CT. SCO should be considered for infiltrating pituitary masses with a mixed intra- and suprasellar location. A history of diabetes insipidus helps to exclude these tumors.