Pituitary spindle cell oncocytoma presented as pituitary apoplexy

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

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

Spindle cell oncocytoma of the pituitary tumor: A rare case report and literature reviews

Introduction

Spindle cell oncocytoma (SCO) of the pituitary gland is increasingly established with improvements in histological and immunohistochemical examination. However, the diagnosis was often mistaken based on imaging studies and nonspecific clinical manifestations.

Purpose

This case is presented to provide an overview of the characteristics of the rare tumor as well as to demonstrate the difficulties in diagnosis and current treatments.

Clinical discussion

The pathogenesis of SCO remains unclear, and a possible origin was described. Further research is needed to optimize pre-operative diagnosis and surgical strategy.

Conclusion

SCO should be considered when images indicate some features. Gross total resection (GTR) after surgery seems to have better long-term tumor control, and radiotherapy may help decrease tumor progression in patients with non-GTR. Regular follow-up is advised because of the higher recurrence rate.

Pituitary spindle cell oncocytoma: illustrative case

BACKGROUND

Spindle cell oncocytoma (SCO) of the pituitary gland is an extremely rare nonfunctional World Health Organization grade I tumor. SCOs are often misdiagnosed as nonfunctional pituitary adenomas on the basis of preoperative imaging. They are often hypervascular and locally adherent, which increases hemorrhage risk and limits resection, leading to increased risk of recurrence. The authors report a case of SCO treated at their institution and provide a review of the current literature.

OBSERVATIONS

SCO of the pituitary gland can be a rare cause of progressively growing pituitary tumors that presents similarly to nonfunctional pituitary adenoma. Endoscopic transsphenoidal resection of the tumor by a multidisciplinary team allowed total resection despite local adherence of the tumor. Postoperatively, the patient’s visual symptoms improved with persistence of secondary adrenal insufficiency and secondary hypothyroidism.

LESSONS

Careful resection is needed due to SCO’s characteristic hypervascularity and strong adherence to minimize local structure damage. Long-term follow-up is recommended due to the tendency for recurrence.

Spindle cell oncocytoma of the sella turcica with anaplastic features and rapid progression in short-term follow-up: a case report with proposal of distinctive radiologic features

We present a rare case of spindle cell oncocytoma (SCO) of the sella turcica with malignant histologic features and rapid progression. A 42-year-old woman experienced bilateral blurred vision and was preoperatively misdiagnosed as having a pituitary macroadenoma on magnetic resonance imaging. After surgery, SCO was diagnosed by the histopathologic features of interlacing fascicles of spindle tumor cells with finely granular, eosinophilic cytoplasm. Focal anaplastic changes and necrosis were present. Immunohistochemically, the tumor cells were positive for vimentin, epithelial membrane antigen, S-100, galectin-3, and thyroid transcription factor 1. Four months later, the tumor had progressed, and second surgery with adjuvant radiotherapy was performed; the patients remains under observation. In this report, we proposed distinctive radiologic features for differential diagnosis between SCO and other pituitary tumors.

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.