Pituitary ependymoma: Report of a rare case with an insight into the histogenesis

Case Report: Sellar Ependymomas: A Clinic-Pathological Study and Literature Review

Ependymomas are primary glial tumors arising from cells related to the ependymal lining of the ventricular system. They are classified into at least nine different molecular subtypes according to molecular phenotype, histological morphology, and tumor location. Primary sellar ependymoma is an extremely rare malignancy of the central nervous system, with only 12 known cases reported in humans. We herein report a case of ependymoma located at the pituitary region in a 44-year-old female patient and discuss the molecular subtype, natural history, clinical presentation, radiological findings, histological features, immunohistochemical characteristics, ultrastructural examinations, treatment, and prognosis of sellar ependymoma. This case report may serve as a helpful reference for clinicians and radiologists in clinical practice.

Null Cell Adenoma of the Pituitary: Pseudo-rosettes Say It Best When Immunohistochemistry Says Nothing At All!

Null cell adenoma is composed of adenohypophyseal cells that show no evidence of any specific cell type differentiation by immunohistochemistry or transcription factors like pituitary-specific positive transcription factor 1 and steroidogenic factor 1. Though rare, pituitary ependymoma and germinoma are also known to occur at sellar region and in such instances, it is challenging to differentiate them from a pituitary null cell adenoma featuring papillary architecture and perivascular pseudo-rosettes. We describe a case of an elderly diabetic lady presenting with headache and blurring of vision for past 3 months due to a sellar tumour. The histology was diagnostically challenging with notable presence of numerous perivascular pseudo-rosettes and negative immunoreactivity for all pituitary hormones. The differential diagnosis and importance of ancillary techniques is discussed.

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.

Pituitary Ependymoma, 10-Year Follow-Up after Partial Resection and Radiation Therapy

Ependymoma usually arises within the ventricles and central canal of the spinal cord. These tumors, found in the sellar region, are extremely rare. We report a case of pituitary ependymoma followed up over 10 years. A 59-year-old male patient presented with fatigue, general weakness, erectile dysfunction, and loss of body hair, including pubic hair. Brain magnetic resonance imaging (MRI) revealed a 3.3×3.5×2.3-cm sellar and suprasellar snowman-shaped enhancing mass. The tumor was partially resected via the trans-sphenoidal approach followed by postoperative radiation therapy. The pathologic confirmation was pituitary ependymoma. At the 10-year follow up, MRI revealed no evidence of tumor progression. With lack of knowledge about pituitary ependymoma, our case is the only case in which the disease has been well controlled over a long period of time without tumor progression.