Arterial Embolization and Second-Look in Spindle Cell Oncocytoma of the Pituitary Gland: Case Report and Review of Literature

Pituitary Spindle Cell Oncocytoma: More than a Grade 1 Tumor?

BACKGROUND/OBJECTIVES

Spindle cell oncocytomas (SCOs) of the pituitary gland are rare tumors often misdiagnosed for nonfunctioning pituitary macroadenomas. Although classified as grade 1, they are often challenging in terms of diagnosis and treatment. Pituitary SCOs harbor peculiar features such as hypervascularity and stronger adherence to surrounding structures, with increased risk of hemorrhage, partial resection, and significantly higher recurrence rate. Almost 100 cases have been reported so far. The role of surgery is still crucial for the decompression of the optic chiasm as well as for achieving diagnosis. However, given the higher tendency of recurrence, the role of postoperative radiotherapy has been investigated over the last few years.

CASE PRESENTATION

Here, we reported a case of a 48-year-old female with a pituitary SCO treated at our institution, in which we focused on diagnosis, treatment, and follow-up.

CONCLUSIONS

This type of tumor presents a challenge related to its higher vascularity and strong adherence to the surrounding structures. Adjuvant radiotherapy is something that should be considered, especially when gross total resection is not achieved, and finally, SCOs require diligent follow-up to monitor for any signs of disease recurrence or progression.

Posterior pituitary tumors and other rare entities involving the pituitary gland

Non-neuroendocrine tumors account for around 10% of all primary neoplasms of the sella. If meningiomas, craniopharyngiomas, and germ cell tumors are excluded, the remaining lesions include a broad spectrum of uncommon, benign, and aggressive, often diagnostically challenging lesions. This review aims to summarize the essential clinicopathological features of tumors of the posterior pituitary gland, infundibulum spectrum expressing thyroid transcription factor 1, and primary sellar atypical rhabdoid teratoid tumor, and provide the criteria for their diagnosis and management.

Pituitary spindle cell oncocytoma: Two cases report and literature review

INTRODUCTION

Pituitary spindle cell oncocytoma (PSCO) is a seldom-encountered type of pituitary neoplasm with distinctive histological features. It was first described as a distinct entity by Roncaroli et al. in 2002. We present two cases of PSCO and discuss its clinical, radiological, and histopathological features, along with a review of the existing literature.

PRESENTATION OF CASE

Two cases underwent trans-nasal transsphenoidal surgery for tumor resection and had different treatment following would be discussed in this article. Both had unique pathology pattern as Pituitary spindle cell oncocytoma.

DISCUSSION

Tumors positive for TTF-1 in the sellar region, such as pituicytoma, granular cell tumor, and spindle cell oncocytoma, originate from the posterior pituitary gland and are rare. The expression of thyroid transcription factor-1 (TTF-1) in these tumors aids in distinguishing them from other pituitary neoplasms.

CONCLUSION

Pituitary spindle cell oncocytoma is a rare entity among pituitary tumors. This case report highlights the clinical, radiological, histopathological, and immunohistochemical features of PSCO. Surgeons and pathologists should consider this rare diagnosis in patients with sellar and suprasellar masses, as early recognition and complete surgical resection can lead to favorable outcomes.

Treatment modalities and outcomes of granular cell tumors and spindle cell oncocytomas of the pituitary gland: an analysis of two national cancer databases

BACKGROUND

Spindle cell oncocytomas (SCO) and granular cell tumors (GCT) are rare primary pituitary neoplasms; the optimal treatment paradigms for these lesions are unknown and largely unexplored. Thus, using national registries, we analyze the epidemiology, management patterns, and surgical outcomes of SCOs and GCTs.

METHODS

The National Cancer Database (NCDB; years 2003-2017) and the Surveillance, Epidemiology, and End Results Program (SEER; years 2004-2018) were queried for patients with pituitary SCOs or GCTs. Incidence, extent of surgical resection, and rate of postoperative radiation use for subtotally resected lesions comprised the primary outcomes of interest. All-cause mortality was also analyzed via time-to-event Kaplan-Meier curves.

RESULTS

SCOs and GCTs have an annual incidence of 0.017 and 0.023 per 1,000,000, respectively. They comprise 0.1% of the benign pituitary tumors registered in NCDB. A total of 112,241 benign pituitary tumors were identified in NCDB during the study period, of which 83 (0.07%) were SCOs and 59 (0.05%) were GCTs. Median age at diagnosis was 55 years, 44% were females, and median maximal tumor diameter at presentation was 2.1 cm. Gross total resection was achieved in 54% patients. Ten patients (7%) had postoperative radiation. Comparing patients with GCTs versus SCOs, the former were more likely to be younger at diagnosis (48.0 vs. 59.0, respectively; p < 0.01) and female (59% vs. 34%, p = 0.01). GCTs and SCOs did not differ in terms of size at diagnoses (median maximal diameter: 1.9 cm vs. 2.2 cm, respectively; p = 0.59) or gross total resection rates (62% vs. 49%, p = 0.32). After matching SCOs and GCTs with pituitary adenomas on age, sex, and tumor size, the former were less likely to undergo gross total resection (53% vs. 72%; p = 0.03). Patients with SCOs and GCTs had a shorter overall survival when compared to patients with pituitary adenomas (p < 0.01) and a higher rate of thirty-day mortality (3.1% vs 0.0%; p = 0.013).

CONCLUSION

SCOs and GCTs are rare pituitary tumors, and their management entails particular challenges. Gross total resection is often not possible, and adjuvant radiation might be employed following subtotal resection.

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.

Pterygovaginal artery as a target of embolization before endoscopic skull base surgery

BACKGROUND

The pterygovaginal artery (PtVA), a recurrent branch of the internal maxillary artery (IMA), can be a feeder of skull base tumors. Preoperative embolization can help endoscopic resection of hypervascular lesions, which is performed under a narrow surgical space with restricted instrumental maneuverability.

METHODS

We performed preoperative embolization in five cases with hypervascular skull base lesions supplied by the PtVA, four of which were resected via endoscopic endonasal approach. In two cases, selective PtVA embolization through the distal IMA was successfully conducted.

RESULTS

In all the cases, intraoperative bleeding during endoscopic resection was easily controlled. The medial and lateral origins of the PtVA from the IMA were demonstrated by cone-beam CT images reconstructed from three-dimensional rotational angiography, and anastomoses around the eustachian tube and soft palate were visualized by superselective angiography.

CONCLUSIONS

The PtVA embolization can be an effective strategy before endoscopic skull base tumor resection. When embolizing through the PtVA, clinicians should be aware of its anatomical variations and dangerous anastomoses. Understanding the surrounding angioarchitecture by angiographic techniques helps ensure safe embolization.