Tumor cells forming sinusoids connected to vasculature are involved in hemorrhage of pineal choriocarcinoma

Pineal Gland Tumors: A Review

Simple Summary

Pineal neoplasms are tumors with different and variable morphological, histological, and radiological characteristics and, consequently different diagnosis and management. Due to their rarity, pineal tumors may be misdiagnosed. Pineal tumors, are divided into germ cell tumors, pineal parenchymal tumors and tumors that derive from adjacent structures. In this review, we report the clinical relevance of the main pineal gland tumors, underlining the importance of studying the triggering causes of pineal region carcinogenesis, to realize appropriate diagnosis and, consequently, better clinical management.

Abstract

The pineal gland is a small, pinecone-shaped endocrine gland that participates in the biological rhythm regulation of vertebrates. The recognized major product of the pineal gland is melatonin—a multifunctional endogenous indoleamine. Accumulating evidence suggests that the pineal gland is important for preserving ideal health conditions in vertebrate. Tumors of the pineal region account for approximately 3–11% of pediatric brain neoplasms but fewer than 1% of brain neoplasms in adults. It is fundamental to expand advanced imaging techniques together with both clinical and laboratory knowledge, to help to differentiate among pineal neoplasms and thus facilitate accurate primary diagnoses and proper therapeutic interventions. In this review, we report the gross anatomy of the pineal gland and its functional significance and discuss the clinical relevance of pineal gland tumors, underlining the importance of identifying the leading causes of pineal region masses.

Adult Brain Tumors and Pseudotumors: Interesting (Bizarre) Cases

Some brain tumors results are interesting due to their rarity at presentation and overwhelming imaging characteristics, posing a diagnostic challenge in the eyes of any experienced neuroradiologist. This article focuses on the most important features regarding epidemiology, location, clinical presentation, histopathology, and imaging findings of cases considered "bizarre." A review of the most recent literature dealing with these unusual tumors and pseudotumors is presented, highlighting key points related to the diagnosis, treatments, outcomes, and differential diagnosis.

Bifocal germinomas in the pineal region and hypothalamo-neurohypophyseal axis: Primary or metastasis?

Whether bifocal germinomas (BFGs) synchronously presenting within the pineal region and the hypothalamo-neurohypophyseal axis (HNA) are primary germinomas of dual-origin remains to be elucidated. We analyzed MRI images and clinical features of 95 neurohypophyseal germinomas and 21 BFG patients and developed a tentative definition of the BFGs. We found dual-primary BFGs (true BFGs) do exist. The fundamental difference between primary and metastatic HNA germinomas was the direction of tumor growth. For a true BFG, the primary HNA tumor grew from the neurohypophysis toward the hypothalamus and almost invaded the whole pituitary stalk. For a false BFG (primary pineal germinoma with HNA metastasis), the metastatic HNA tumor first appeared at the third ventricular floor (TVF), grew toward the neurohypophysis, but commonly did not invade the inferior pituitary stalk. Compared to false BFGs, true BFGs commonly had diabetes insipidus as the first symptom, dysfunction of the anterior pituitary, no high-intensity MRI signal at the posterior pituitary, a larger extension of the HNA tumor, and fewer numbers of remote lesions from cerebrospinal fluid seeding. Accordingly, 12.8% (12/96) of our germinoma patients had true BFGs, and of these, 58.3% (7/12) were free of remote metastases and warranted treatment with limited radiotherapy. True BFGs with remote metastases and all false BFGs should be treated with craniospinal irradiation. We provided evidence for the diagnosis of true BFGs that is useful for radiotherapy strategy, suggesting that the existence of metastasis to other locations is not a diagnostic criterion for a true BFG.

Determining an Optimal Cutoff of Serum β-Human Chorionic Gonadotropin for Assisting the Diagnosis of Intracranial Germinomas

Background

Beta (β)-human chorionic gonadotropin (β-HCG) is used to confirm the diagnosis and plan treatment of intracranial germinomas. However, the cutoff values of serum β-HCG in diagnosis of intracranial germinomas reported in the literature are inconsistent. To establish an appropriate cutoff value of serum β-HCG for diagnosis of intracranial germinomas, we retrospectively reviewed the records of intracranial tumor patients who received serum β-HCG and α-fetoprotein (AFP) tests for diagnostic purposes at our hospital from 2005 to 2014.

Methods

A total of 93 intracranial germinomas and 289 intracranial non-germ cell tumors were included in this study. Receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of 3 cutoffs (0.1, 0.4, and 0.5 mIU/mL) for diagnosing intracranial germinomas. The serum β-HCG level of intracranial germinoma patients was further analyzed to investigate the effect of metastasis status and tumor location on serum β-HCG level.

Results

The area under the ROC curve was 0.81 (P < .001), suggesting β-HCG is an effective marker. Of the 3 cutoff values, 0.1 mIU/mL possessed a highest sensitivity (66.67%) and good specificity (91%). Although there was no β-HCG level difference between metastatic and non-metastatic intracranial germinoma patients, the diagnostic rate of metastatic neurohypophyseal germinomas was significantly higher than that of its non-metastatic counterpart (P < .05), implying that the location of the germinoma might need to be considered when β-HCG is used as a marker to predict metastasis.

Conclusions

Determining an optimal cutoff of serum β-HCG is helpful for assisting the diagnosis of intracranial germinoma.