Primary Tumors of the Posterior Pituitary Gland: A Systematic Review of the Literature in Light of the New 2017 World Health Organization Classification of Pituitary Tumors

OBJECTIVE

The rare clinical entity of primary posterior pituitary tumors (PPTs) includes pituicytomas, granular cell tumors, spine cell oncocytomas, and sellar ependymomas. The recent World Health Organization classification of PPTs based on thyroid transcription factor 1 positivity has led to more investigations into the epidemiology, clinical presentation, nature history, histologic features, and operative characteristics of these tumors. The aim of this review is to summarize the characteristics of primary PPTs.

METHODS

Our summary involved an in-depth review of the literature on PPTs. Our systematic review was carried out using the PubMed database and PRISMA guidelines.

RESULTS

An initial search identified 282 publications. After strict application of the inclusion criteria, we found 16 articles for case series of patients with primary PPT (N > 5), which were included in our table for literature review. An additional 10 articles were review articles on PPTs published in the last 20 years and were used as resource for our systematic review. An extensive analysis was then performed to extract relevant clinical data with respect to the clinical radiologic histopathologic profile of primary PPTs and their treatment outcome.

CONCLUSIONS

Primary PPTs are a rare group of pituicyte-derived low-grade nonneuroendocrine neoplasms that arise from the sellar region. The nondescript radiographic findings and subtle endocrine abnormalities also veil their accurate diagnostic prediction. As shown through the narrative as well as the literature review, there is still a lot to be understood about PPTs. A prospective multicenter registry of these rare tumors would benefit both the neurosurgical as well as the endocrinologic knowledge base.

Pituitary Ependymoma: A Case Report and Review of the Literature

BACKGROUND

Pituitary ependymoma is exceptionally rare. Its etiology, clinical presentation, radiologic feature, and treatment strategy are still a matter of debate. Only 7 human cases with limited data were reported in the English literature, and now we described another case of pituitary ependymoma. We also systematically reviewed previously reported cases and described its potential etiology, clinical presentation, radiologic features, pathology, immunohistochemical analysis, and ultrastructural examinations.

CASE DESCRIPTION

A lesion in pituitary fossa was discovered in a 40-year-old man after suffering a progressive deterioration of vision in his right eye for >1 year with intermittent headache. The lesion was microsurgically resected and proved to be ependymoma upon pathologic and histologic examination. The patient made a fully recovery after surgery.

CONCLUSIONS

To our knowledge, only 7 patients with ependymoma in the sellar region have been described in the English literature. We reported 1 more case of pituitary ependymoma and discussed the potential etiology, clinical presentation, radiologic features, pathology, immunohistochemical analysis, ultrastructural examinations, treatment, surgery, radiotherapy, chemotherapy, and prognosis of pituitary ependymoma. The case report may serve as a helpful reference for clinicians and radiologists.