Pituicytoma in a patient with Cushing's disease: case report and review of the literature

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.

Synchronous Posterior and Anterior Pituitary Tumors: A Case Report of a Hypothetic Paracrine Relationship

Tumors of the posterior pituitary are a distinct group of low-grade sellar neoplasms. Furthermore, the coexistence with an anterior pituitary tumor is extremely unlikely and could not be a mere coincidence and could be a paracrine relationship. Here, we present a case of 41-year-old woman with Cushing syndrome and two pituitary masses on magnetic resonance imaging. Histologic examination shows two distinct lesions. The first consisted of a pituitary adenoma with intense adrenocorticotropic hormone immunostaining and the second lesion consisted of a proliferation of pituicytes arranged in vague fascicles or pituicytoma. After a narrative review of the literature, we found that synchronous pituitary adenoma and a thyroid transcription factor 1 (TTF-1) pituitary tumor were only reported eight times in the past. These patients included two granular cell tumors and six pituicytomas and all of them coexisted with pituitary adenomas, seven functioning and one nonfunctioning. We analyze the hypothesis of a possible paracrine relationship for this concomitance, but this exceedingly rare situation is still a matter of debate. To the best of our knowledge, our case represents the ninth case of a TTF-1 pituitary tumor coexisting with a pituitary adenoma.

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 Associated with Suspected Cushing’s Disease: Two Case Reports and a Literature Review

(1) Background: Pituicytomas are rare gliomas located in the neurohypophysis or infundibulum. A misdiagnosis of pituicytoma as pituitary adenoma is common because of similar location and occasional endocrine disturbances. (2) Case presentation: We present two cases with the comorbidity of pituicytoma and Cushing’s disease (CD). Case 1 is that of a 51-year-old woman, the first reported case of the comorbidity of pituicytoma, CD, and central diabetes insipidus. She received a diagnosis of CD and central diabetes insipidus. After transsphenoidal surgery, histopathology confirmed the diagnosis of pituicytoma and adrenocorticotropin-secreting microadenoma; case 2 is that of a 29-year-old man who received a biochemical diagnosis of CD, but he received a histopathological confirmation of only pituicytoma. Both patients achieved a remission of hypercortisolism without relapse during the follow-up, but they developed hypopituitarism after surgery. We also reviewed all published 18 cases with the comorbidity of pituicytoma and any pituitary adenoma. (3) Conclusions: Pituicytoma might present pituitary hyperfunction disorders such as CD or acromegaly, with or without pathologically confirmed pituitary adenoma. CD is the most common hyperpituitarism occurring concurrently with pituicytomas. The remission rate and hypopituitarism after surgery seem similar or slightly lower in CD than in common pituitary adenomas, but the long-term prognosis is unexplored.

Recommendation to improve the WHO classification of posterior pituitary tumors as a unique entity: evidence from a large case series

INTRODUCTION

Most studies reporting posterior pituitary tumors (PPTs) are small case series or single cases.

METHODS

Patients with a histological diagnosis of PPT from January 2010 to December 2021 in a tertiary center were identified. We reported clinical symptoms, endocrine assessments, radiological and pathological features, and surgical outcomes of PPTs.

RESULTS

A total of 51 patients (23 males, 51.3 ± 10.3 years old) with PPT were included in this study. Major symptoms were visual defects, headache, and hypopituitarism, while diabetes insipidus was uncommon (9.8%). The typical radiological feature was homogeneous enhancement (84.3%) of a regular-shaped mass on T1 contrast imaging without cystic change, calcification, or cavernous sinus invasion. We achieved gross total resection in 38/51 patients (74.5%). Pathologically, all tumors showed thyroid transcription factor 1 immunoreactivity. Among 29 patients with suprasellar PPTs, postoperative hemorrhage due to tumor residue was encountered in 2/15 cases in the transcranial group and 0/14 in the endoscopy group. Patients with spindle cell oncocytoma (SCO) were more likely to be surgically treated (25% vs 0%, P = 0.018), harbor a higher Ki-67 index (16.7% vs 0% > 5% P = 0.050), and present a lower 2-year recurrence-free survival rate (67.5% vs 90.9%) compared with patients with pituicytoma or granular cell tumor.

CONCLUSION

PPTs should be considered in the differential diagnosis of patients with sellar and suprasellar masses with a regular lesion with homogeneous enhancement. SCOs had high proliferation activity and risk of recurrence.

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.

Pituicytoma associated with Cushing's disease: a case report and literature review

Pituicytoma is a rare tumor that has been recently recognized and described, where only few reported cases of pituicytoma associated with Cushing’s disease. We describe a case of a 47 years old female with a history of high cortisol levels and a diagnosis of Cushing’s disease was made. Brain magnetic resonance imaging showed lesion in pituitary gland compatible with microadenoma and tumor resection was carried out. The histopathological findings were of a pituicytoma with positive thyroid transcription factor-1 immunostain.

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.

Pituicytoma Associated with Acromegaly and Cushing Disease

BACKGROUND

Pituicytoma is a rare neoplasm arising in the sellar region (World Health Organization grade I). Clinically, pituicytomas mimic nonfunctioning pituitary macroadenomas and are occasionally incidentally discovered at autopsy. Pituitary adenomas can occur with other sellar pathologies, and the term "collision sellar lesions" has been coined for this rare entity. There have only been a few reports of the coexistence of pituicytoma and pituitary adenoma. We present 2 cases of pituicytoma coexisting with acromegaly and Cushing disease.

CASE DESCRIPTION

Case 1: A 29-year-old woman had acromegaly. The macroadenoma was partially removed in her first surgery; thus an endonasal reoperation was required for debulking and posterior radiosurgery. Pituicytoma coexisting with somatotropinoma was diagnosed on pathologic examination. Case 2: A 33-year-old woman had adrenocorticotropic hormone-dependent Cushing disease. She underwent endonasal resection. Undetectable postoperative cortisol levels provided evidence that the underlying adrenocorticotropic hormone source was successfully removed. On the basis of morphologic features and the immunohistochemical profile, pituicytoma was diagnosed on pathologic examination. Pituitary adenoma was not confirmed histologically in this patient.

CONCLUSIONS

Only 117 cases of pituicytoma have been reported since it was first described in 1955. Before our report, only 5 cases of patients with pituicytoma coexisting with pituitary adenoma had been described. The coexistence of these 2 entities may not just be a mere coincidence but may be due to a yet unknown pathophysiologic link or common progenitor lineage of both lesions. Association between pituicytoma and pituitary adenoma is increasingly being reported.

A rare case of pituicytoma presenting with severe Cushing disease: A case report and review of literature

RATIONALE

Pituicytomas are exceptional rare tumors in the sellar and suprasellar regions with clinical manifestations, such as headache, visual disturbance, hypopituitarism, and decreased libido. Unlike that of common pituitary adenoma, the association between pituicytoma and Cushing disease (CD) is extremely rare. There were only 6 reported cases till now. In the current study, we describe an unusual case of pituicytoma associated with severe CD with a recurrence-free follow-up period of 49 months.

PATIENT CONCERNS

A 32-year-old woman was referred to our hospital with moon face, central obesity, and purple stripes on the lower limbs.

DIAGNOSES

The plasma cortisol level was 1122 nmol/L. The low-dose dexamethasone suppression test failed to suppress plasma cortisol. This test provided evidence of nonpituitary-dependent CD. However, magnetic resonance imaging demonstrated a sellar mass measuring approximately 7.6 × 5.7 mm. The patient was diagnosed with pituitary microadenoma. Histopathological analysis of the tissue sections based on the findings from the immunohistochemical staining diagnosed it as pituicytoma.

INTERVENTIONS

Transsphenoidal surgery was performed to remove the pituitary mass.

OUTCOMES

Within 2 months postoperatively, the patient's blood pressure and cortisol level decreased gradually and normalized on the 6th month when other symptoms of CD also disappeared. The patient is presently free from recurrence 49 months after the initial diagnosis.

LESSONS

Based on the postoperative remission, CD was caused by pituitary disorders. A reasonable assumption is that an extremely small coexisting adenoma was not detected by the surgeon and washed out during the dissection. Another possible explanation might be the mass effect caused by this intrasellar lesion.

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.

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

PURPOSE

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

METHOD

Cross-sectional study with retrospective data.

RESULTS

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

CONCLUSION

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

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.

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.

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 Coexisting With Corticotroph Hyperplasia: Literature Review With One Case Report

Pituicytoma is a rare, low-grade glial neoplasm that arises in the neurohypophysis or infundibulum and usually presents as pituitary gland enlargement. They are often misdiagnosed as pituitary adenomas. Causes have varied for high serum adrenocorticotropic hormone level reported in a few patients with pituicytoma.We report a rare case of pituicytoma accompanied by corticotroph hyperplasia-a challenging diagnosis guided by clinical presentations, radiological signs, and biopsy.We present a case of pituicytoma with corticotroph hyperplasia in a 46-year-old woman with typical Cushing syndrome. Magnetic resonance imaging revealed a lesion in the sellar area with equal T1 and T2 signals and marked homogeneous enhancement. We present detailed analysis of the patient's disease course and review pertinent literature. Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal. Because of this, there is no need to conduct special ethic review and the ethical approval is not necessary.The patient underwent a surgical exploration and tumor resection through a trans-sphenoidal approach. Pathologic results revealed pituicytoma and corticotroph hyperplasia. As adrenocorticotropic hormone and cortisol levels did not decrease to normal, the patient received radiotherapy and recovered uneventfully. No recurrence was found over 8 years of follow-up.Pituicytoma is a rare type of sellar tumor. Pituicytomas in patients with Cushing syndrome are rarer still. To our knowledge, this is the first report of Cushing syndrome caused by corticotroph hyperplasia in a pituicytoma patient.

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.

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.

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.

[Pituitary pituicytoma]

Pituicytomas are rare entities which develop in the neurohypophysis. They were included in the last World Health Organization (WHO) Classification of Central Nervous System Tumours in 2007, but for many years they have been confused with other pituitary tumours. We report the case of a 31-year-old woman who was diagnosed of a tumour in the suprasellar region during an infertility study due to hypogonadotropic hypogonadism and slight hyperprolactinemia. A standard pterional approach was performed, achieving total tumour excision. After the surgery the patient suffered bitemporal hemianopsia, diabetes insipidus and panhypopituitarism, although she recovered from the latter 2 in a few weeks. We conducted a review of the most common clinical and radiological features of this entity, as well as the treatments proposed in the literature to treat this rare tumour.

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.

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.

Spindle cell oncocytoma of the pituitary and pituicytoma: Two tumors mimicking pituitary adenoma

BACKGROUND

Spindle cell oncocytoma (SCO) and pituicytoma are rare nonfunctioning tumors of the pituitary. Both tumors are low grade and macroscopically indistinguishable from a nonfunctioning pituitary adenoma.We report one case of SCO and one case of pituicytoma and review the previous literature.

CASE DESCRIPTION

One patient was a 39-year-old man who presented with progressive headache, visual blurring, and polyuria of 3-year duration. He underwent partial resection (30% of the tumor) and postoperative adjuvant radiation therapy. Histopathology revealed SCO. However, after 9 months, the residual tumor grew and partial resection (70% of the tumor) was performed again. Four months after the second surgery, the tumor recurred again and he underwent transsphenoidal resection of the tumor with stable residual tumor to date. The other patient was a 59-year-old man who presented with a 3-month history of visual decline, fatigue, difficulty in writing, and polyuria. He underwent transsphenoidal resection (total) of the tumor. Histopathology revealed pituicytoma. He has been stable without evidence of recurrence for 1 year and 4 months.

CONCLUSION

To date, there are 15 reported cases of SCO and 45 reported cases of pituicytoma including our cases. An incomplete resection of the tumor was a significant risk factor for recurrence in both SCO and pituicytoma (P = 0.0014 and P = 0.019, respectively). These tumors have a tendency to be hypervascular, which may hamper total resection. Epithelial membrane antigen (EMA) and mitochondria positivity is characteristic to SCO and they are considered to be important immunomarkers to distinguish these tumors.