Extent of surgical resection and tumor size predicts prognosis in granular cell tumor of the sellar region

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.

Supra-sellar granular cell tumor: Report of a case with literature review

INTRODUCTION AND IMPORTANCE

Granular cell tumor (GCT) originating from the sellar and suprasellar regions, specifically from the neurohypophysis, is a rare neoplasm. Distinguishing GCT from other pituitary tumors, including pituitary adenoma, pituicytoma, and spindle cell oncocytoma, poses significant challenges. Here, we present a rare case of GCT originating from the posterior pituitary in the supra-sellar region.

CASE PRESENTATION

A 41-year-old woman, with no past medical history, presented to neurology department with decreased visual acuity and peripheral facial paralysis since 3 months. The MRI showed a well-defined supra-sellar, retrochiasmatic, oblong, hypothalamic expansive process. It was isointense T1-weighted, discretely hypotensive T2-weighted, measuring 19x17x16 mm, suggesting pituicytoma or craniopharyngioma. An endoscopic transsphenoidal surgical resection was performed. Microscopic examination showed a proliferation of diffuse architecture made up of rounded polyhedral cells with granular eosinophilic cytoplasm. On immunohistochemistry, tumor cells expressed diffusely TTF1, S-100 protein and SOX-10 confirming the diagnosis of supra-sellar GCT.

DISCUSSION AND CONCLUSION

GCTs are rare neoplasms that predominantly exhibit benign behavior, while the malignancy rate remains at 2 %. Histopathology serves as the definitive diagnostic approach for GCTs. These tumors are resistant to radiotherapy and chemotherapy, necessitating surgical resection as the primary treatment modality. Due to the potential absence of distinct tumor masses and local tissue infiltration by tumor cells, complete excision is crucial, with resection extent extending beyond areas of infiltration.

Granular Cell Tumor and Spindle Cell Oncocytoma of the Pituitary Gland: Imaging and Intraoperative Cytology Diagnostic Dilemmas and Management Challenges

BACKGROUND

 Tumors arising from the posterior pituitary gland are rare and closely resemble pituitary adenoma in presentation and imaging. Most of them come as a histopathologic surprise. We have analyzed the posterior pituitary tumors managed in our institute and have discussed the dilemmas in imaging, challenges in intraoperative squash cytology, and surgical management.

METHODS

 We retrospectively reviewed our operative database of pituitary tumors over the past 10 years, which included five posterior pituitary tumors (three granular cell tumors [GCTs] and two spindle cell oncocytomas [SCOs]). Clinical, imaging, and endocrine characteristics; intraoperative details; histopathologic features; and postoperative outcomes were collected and analyzed.

RESULTS

 The mean age of the patients was 47 years. All patients presented with varying degrees of vision loss. Radiology revealed a sellar / suprasellar lesion with the pituitary gland seen separately in two of three GCTs, whereas a separate pituitary gland could not be identified in both the SCOs. Pituitary adenoma was a radiologic diagnosis in only two of five cases. Three patients underwent a transsphenoidal surgery, whereas two underwent surgery by the transcranial approach. Intraoperative cytology was challenging, though a possibility of posterior pituitary tumor was considered in three of four cases, whereas one was considered meningioma. All the tumors were very vascular and influenced the extent of resection.

CONCLUSIONS

 GCTs and SCOs are relatively uncommon tumors that are difficult to diagnose on preoperative imaging. Intraoperative squash cytology too can pose challenges. A preoperative suspicion can prepare the surgeon for surgery of these hypervascular tumors. The transcranial approach may be necessary in cases of uncertainty in imaging.

Comprehensive Genomic Characterization of A Case of Granular Cell Tumor of the Posterior Pituitary Gland: A Case Report

Granular cell tumors of the pituitary belong to a rare family of neoplasms, arising from the posterior pituitary gland. Although considered benign, they may cause significant morbidity and residual disease after resection can lead to poor clinical outcomes. Currently, there is no known medical therapy for any posterior pituitary gland tumor, in part due to sparse molecular characterization of these lesions. We report data from whole exome sequencing of a case of granular cell tumor of the pituitary, performed under an institutional review board approved protocol. A 77 year-old female underwent resection of an incidentally diagnosed pituitary mass that was causing radiographic compression of the optic nerves with a subclinical temporal field defect and central hypothyroidism. The pathology of the resected specimen demonstrated a granular cell tumor of the posterior pituitary gland. Whole-exome sequencing revealed mutations predicted to be deleterious in key oncogenes, SETD2 and PAX8, both of which have been described in other cancers and could potentially be amenable to targeted therapies with existing approved drugs, including immune checkpoint inhibitors and histone deacetylase inhibitors, respectively. To our knowledge, this is the first comprehensive genomic characterization of granular cell tumor of the posterior pituitary gland. We report mutations in oncogenes predicted to be deleterious and reported in other cancers with potential for therapeutic targeting with existing pharmacologic agents. These data provide new insights into the molecular pathogenesis of GCT of the pituitary and may warrant further investigation.

Granular Cell Tumor: A Technical Approach for Resection of a Rare Suprasellar Mass

BACKGROUND AND IMPORTANCE

Granular cell tumors (GCTs) of the sellar and suprasellar regions are rare tumors that may be managed surgically by multiple strategies. The technical approaches for these tumors have rarely been described in the literature.

CLINICAL PRESENTATION

We introduce the case of a patient presenting with dizziness and headaches who was found to have a suprasellar and retrochiasmatic mass and eventually underwent surgical resection. We discuss the characteristics of this tumor, and the current state of the literature. Also included are details regarding the surgical approach utilized in this case, and a discussion of the various surgical approaches for this type of tumor.

CONCLUSION

There are several approaches for the surgical resection of suprasellar GCTs, and the approach utilized may depend on patient and/or surgeon considerations. Patient-specific considerations must be made to ensure maximal safe resection of these lesions.

Rare neurohypophyseal tumor presenting as giant pituitary macroadenoma with cavernous sinus invasion - A case report and review of literature

Background:

Granular cell tumors (GCTs) of the pituitary are rare tumors of posterior pituitary that can present as giant pituitary macroadenoma due to the slow indolent growth of the tumor. We are reporting this case due to the rarity of GCT and usually these tumors are confined to the suprasellar region since they are arising from the pituitary stalk. GCTs that attain such giant size with cavernous sinus invasion are still rarer.

Case Description:

A 38-year-old female who presented with progressive deterioration of vision and on evaluation by magnetic resonance imaging showed a giant pituitary macroadenoma with bilateral cavernous sinus invasion. The patient underwent pterional craniotomy and near-total excision of the lesion was done due to high vascularity and firmness of the tumor. Histopathology examination of the lesion showed spindle to globular cells with granular cytoplasm and was reported as GCT of the pituitary.

Conclusion:

GCTs are WHO grade1 non-neuroendocrine tumors arising from neurohypophysis and infundibulum. Complete excision is usually difficult due to the high vascularity, firm consistency, and local invasion of the tumor to the cavernous sinus and optic apparatus.

Surgical resection of granular cell tumor of the sellar region: three indications

PURPOSE

This case series evaluates the surgical management of granular cell tumor (GCT) of the sellar region. This rare entity presents a unique diagnostic and surgical challenge.

METHODS

Institutional neuropathology databases at Brigham and Women's Hospital and Massachusetts General Hospital were searched for cases with a tissue diagnosis of GCT, and with a location in the sellar region. Patient, treatment, tumor, and follow-up data were extracted.

RESULTS

Three patients had a diagnosis of GCT of the sellar region occurring over an 18-year period. All three patients were followed postoperatively at our multidisciplinary pituitary center (median follow-up = 30 months; range 12-30 months). Hormonal disturbances, an incidental lesion requiring diagnosis, and neurological symptoms were indications for surgery in these patients. Two patients underwent a craniotomy and one underwent endoscopic transsphenoidal surgery. All three patients were free of tumor recurrence at last follow-up. In one case tested, positive thyroid transcription factor-1 (TTF-1) immunohistochemistry was observed.

CONCLUSION

GCT is generally a benign tumor of the sellar region. Surgical resection is the standard treatment, more recently with transsphenoidal surgery when indicated. Surgical resection results in optimal outcome for patients.

Welcoming the new WHO classification of pituitary tumors 2017: revolution in TTF-1-positive posterior pituitary tumors

The fourth edition of the World Health Organization classification of endocrine tumors (EN-WHO2017) was released in 2017. In this new edition, changes in the classification of non-neuroendocrine tumors are proposed particularly in tumors arising in the posterior pituitary. These tumors are a distinct group of low-grade neoplasms of the sellar region that express thyroid transcription factor-1, and include pituicytoma, granular cell tumor of the sellar region, spindle cell oncocytoma, and sellar ependymoma. This short review focuses on the classification of posterior pituitary tumors newly proposed in EN-WHO2017, and controversies in their pathological differential diagnosis are discussed based on recent cases.