Spindle cell oncocytoma of the adenohypophysis: Report of a rare case and review of literature

Risk factors for tumor recurrence and progression of spindle cell oncocytoma of the pituitary gland: a systematic review and pooled analysis

INTRODUCTION

Spindle cell oncocytoma (SCO) is an extremely rare sellar neoplasm. No observational studies have been reported so far to investigate the prognostic factors of this tumor entity. This systematic review aimed to elucidate the risk factors for tumor recurrence/progression of SCO.

METHODS

We searched for relevant articles in PubMed and Web of Science. Studies providing individual patient data with follow-up information of SCO cases were included. Pearson's Chi square and Fisher's exact test were used for categorical variables while t test or Mann-Whitney tests were applied for continuous variables, if applicable. We used the Cox regression model to assess the effects of suspected variables on progression-free survival (PFS).

RESULTS

A total of 38 case reports and case series comprising of 67 SCOs were included for final analyses. Recurrent/progressive tumors were noted in 38.8% of cases. Among the clinicopathological factors, only the extent of surgery was a significant risk factor for tumor recurrence/progression. SCO patients with a subtotal resection had a significantly higher risk for tumor relapse in comparison with complete removal (HR 7.51; 95% CI 1.75-32.31; p = 0.007).

CONCLUSION

Our study demonstrated the characteristic clinicopathological features of SCOs with a high recurrence/progression rate and outlined the predictor for tumor relapse. Failure to achieve gross total resection is the only risk factor for tumor recurrence/progression.

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.

Trans-nasal Trans-sphenoidal Endoscopic Resection of Spindle Cell Oncocytoma of Adenohypophysis: The First Case Report in a Child and a Review of Literature

Spindle cell oncocytoma (SCO) is a rare tumor of adenohypophysis, arising from the sellar region. So far, about 35 cases of SCO in the sellar region have been reported. In this report, we present the first case of pediatric SCO and review the literature concerning the tumor origin, clinical presentations, radiological features, and treatment modalities. An 8-year-old male was referred to our clinic with progressive visual loss in the left eye and headache over the past 6 months. Cranial magnetic resonance imaging revealed a solid adenohypophysis mass with suprasellar extension, as well as compression and displacement of the optic chiasm. The patient underwent endoscopic trans-sphenoidal resection of the tumor. The tumor was diagnosed as SCO based on the histological study. He did not receive radiation therapy. The patient's condition remained stable, with no radiological recurrence in the past follow-up 2 years after the surgery.

Spindle cell oncocytoma of the pituitary gland

OBJECTIVE

The authors report the diagnosis, management, and outcomes of 6 cases of spindle cell oncocytoma (SCO) in an effort to guide clinical diagnosis and management of these uncommon lesions.

METHODS

This study is a retrospective review of cases involving adult patients who underwent resection of pituitary lesions at the authors' institutions between January 2000 and October 2017. The authors identified patients with histopathological confirmation of SCO and collected clinical data, including preoperative, perioperative, and postoperative management, complications, and outcomes.

RESULTS

Six patients with SCO were identified. Clinical findings at initial presentation included visual disturbances, dizziness, and headache. All patients underwent resection. Four resections were initially performed by the transsphenoidal approach, and 2 resections were performed by craniotomy at an outside institution with subsequent transsphenoidal reoperations. Neither necrosis nor increased mitotic activity was seen in the tumor samples. All samples stained positive for S100 protein and thyroid transcription factor 1 and negative for glial fibrillary acidic protein and pituitary hormones. Five of the samples stained positive for epithelial membrane antigen. The average MIB-1 index was 8.3% (range 2-17). Postoperatively, 3 of the 6 patients received further treatment for progression of residual tumor or for recurrence, 2 have stable residual tumor, and 1 has had no recurrence after gross-total resection. Two patients developed postoperative complications of transient sixth cranial nerve palsy and diplopia. There were no other complications.

CONCLUSIONS

SCO poses both a diagnostic and therapeutic challenge. These tumors are often initially misdiagnosed as nonfunctional pituitary adenomas because of their sellar location and nonspecific symptomatology. Postoperatively, SCO must also be distinguished from other neoplasms of the posterior pituitary gland through histopathological examination. Resection of SCO can be challenging, given its highly vascular and adherent nature. Long-term follow-up is critical, as the tumor is associated with higher recurrence and progression rates compared to other benign neoplasms of the sella.

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.

Spindle Cell Oncocytoma of the Anterior Pituitary Presenting with an Acute Clinical Course Due To Intraventricular Hemorrhage. A Case Report and Review of Literature

Patient: Male, 56

Final Diagnosis: Spindle cell oncocytoma of the adenohypophysis

Symptoms: Disturbed conscious level • visual disturbances

Medication: —

Clinical Procedure: Urgent craniotomy

Specialty: Neurosurgery

Spindle cell oncocytoma of the adenohypophysis: two case reports and a review of the literature

Spindle cell oncocytoma (SCO) of the adenohy-pophysis is a rare tumor in the sellar region. Due to its rarity, little information is available regarding SCO. It is often misdiagnosed as another type of sellar tumor. In the present study, two cases of SCO were reported. One patient was a 35-year-old female presenting with decreased visual acuity, amenorrhea and lactation. The other patient was a 62-year-old female with no clear symptoms or signs. Cranial magnetic resonance imaging (MRI) revealed a suprasellar mass with marked homogeneous enhancement in the two cases. A craniotomy was performed to completely resect the tumors. The tumors were immunopositive for vimentin, epithelial membrane antigen (EMA), S-100 and thyroid transcription factor-1 (TTF-1). The tumors were pathologically diagnosed as SCO. No recurrence occurred during the follow-up period of 15–21 months. In the present study, the literature was reviewed and the clinical data, imaging features, intraoperative findings and recurrence of 24 cases were analyzed in the literature as well as the present two cases. The average age of the SCO patients was 58.5 years and no gender preference was observed for the disease. The tumor exhibited homogeneous enhancement on the MRI. The intraoperative assessment revealed that the tumor had a rich blood supply and the SCO tumors were immunopositive for vimentin, S-100, EMA and TTF-1. These findings provided valuable clinical data for the preoperative diagnosis and surgical removal of SCO tumors.

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.

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.