Pineoblastoma in adults

Post-Surgical Prognosis of Patients with Pineoblastoma: A Systematic Review and Individual Patient Data Analysis with Trends over Time

Most of the literature on pineoblastoma consists of case reports and single-institution series. The goal of this systematic review and individual patient data (IPD) analysis was to summarize the existing literature, identify factors associated with overall survival (OS), and provide a contemporary update on prognosis for patients with pineoblastoma. Forty-four studies were identified with 298 patients having IPD. Kaplan-Meier analyses were used to report survival outcomes based on age, tumor metastases, extent of resection (EOR), adjuvant therapy, and publication year. Cox regression was performed to identify independent predictors of time to mortality. Multivariable recursive partitioning analysis was used to identify the most important subgroups associated with mortality. Patients were classified based on publication year before and after the last systematic review on this topic (pre-2012 and 2012 onwards) and compared using univariate and multivariable analyses. This study demonstrates that EOR less-than-gross total resection, metastatic presentation, adjuvant chemotherapy without radiation, and tumor presentation in children less than three years old are associated with poorer prognosis. Since 2012, the 5-year actuarial OS has improved from 32.8% to 56.1%, which remained significant even after accounting for EOR, age, and adjuvant therapy. Pineoblastoma remains a severe rare disease, but survival outcomes are improving.

Concomitant, Single Burr Hole Endoscopic Third Ventriculostomy and Tumor Biopsy for Pineal Lesions: Feasibility, Safety, and Benefits

Obtaining a prompt diagnosis, avoiding indwelling ventriculoperitoneal shunt, and enhancing the predictive value of pathologic examinations are only some of the advantages conferred by a simultaneous third ventriculostomy and tumor biopsy in patients with pineal region tumors. The objective of this study was to retrospectively search the literature on concomitant, single burr hole endoscopic third ventriculostomy (ETV) and tumor biopsy (TB) for pineal region tumors and to analyze the feasibility, surgical safety, and benefits of these 2 combined procedures. Consequently, a comprehensive, systematic literature search was performed in compliance with the updated PRISMA 2020 guidelines within electronic databases MEDLINE/PubMed, EMBASE, PLOS, and Cochrane Library. Statistical analysis was performed with IBM SPSS 28.0.1.1(14), using Kendall's and Spearman's tests, with a P < 0.05 considered significant. A total of 25 studies were selected and included in this review, for a total of 368 patients (mean age 20.6 years; range 1-86 years; SD 17.5). More than two-thirds of the procedures were operated with a rigid endoscope and 27.6% were performed with either a flexible endoscope, a combination of the 2, or not otherwise specified. Germinoma represented the most frequent diagnosis (20.1%) followed by astrocytoma (12.9%) and pineocytoma (9.9%). The single-entry approach allowed a correct histologic diagnosis in 88.7% of the examined cases. Summing up, concomitant ETV and TB represent a valuable option for the management of non-communicating hydrocephalus and the initial assessment of pineal region tumors. The histologic confirmation rate was 88.7% in the examined cohort, with only 10% of the biopsies yielding inconclusive results.

Radiotherapy Is Associated With Improved Overall Survival in Adult Pineoblastoma: A SEER Database Analysis

OBJECTIVE

Pineoblastomas (PBLs) are rare high-grade tumors treated variably with surgery and/or radiation. The role of surgical extent of resection and radiotherapy (RT) in adult PBL remains unclear. We queried the Surveillance, Epidemiology, and End Results (SEER) database to assess these variables' effects on overall survival (OS) in adult PBL.

METHODS

The SEER (1975-2016) database was queried for adult patients with diagnosis of PBL (ICD-0-3: 9362/3). Variables extracted included age, sex, race, geographical region, extent of tumor resection, RT, chemotherapy (CT), and OS data. Comparisons were performed with the χ2 test for categorical variables, Cox proportional hazards models to assess the association of clinical variables on OS, and Kaplan-Meier curves were generated.

RESULTS

A total of 201 patients with PBL were identified with mean age 40.0 years (interquartile range 27.0-51.0) and most patients being male (53%) and Caucasian (77%). 101 (50%) patients received RT, and gross total resection was achieved in 83 (41%). Age stratification by decade revealed statistically significant poorer OS in patients aged ≥70 years. In bivariate analysis, RT with or without surgery was associated with improved 5-year OS compared with no RT (77.3% vs. 63.2%, P = 0.020). In multivariate analysis, age was a poor prognostic factor for OS (P < 0.001) and RT did appear to improve survival (P = 0.020). Extent of surgical resection was not significantly associated with improved survival.

CONCLUSIONS

In adult patients with PBL, RT may offer an OS benefit irrespective of surgery or extent of surgical resection. Patients ≥70 years of age are associated with poorer OS.

Epidemiology of pineoblastoma in the United States, 2000-2017

Background

Pineoblastoma (PB) is a rare malignant brain tumor originating in the pineal gland. Here, we provide a comprehensive epidemiological analysis of PB in the United States from 2000 to 2017.

Methods

Data on 1133 patients with PB were acquired from the Central Brain Tumor Registry of the United States, in collaboration with the Centers for Disease Control and Prevention and the National Cancer Institute, from 2000 to 2017. Age-adjusted incidence rates (AAIRs) per 100 000 and incidence rate ratios (IRRs) were reported for age, sex, race, and ethnicity. Using the National Program of Cancer Registries survival database, median survival and hazard ratios (HRs) were evaluated for overall survival from 2001 to 2016.

Results

Incidence was highest in ages 0-4 years (AAIR: 0.049, 95% CI: 0.042-0.056), decreasing as age increased. Incidence was higher among patients who are Black compared to patients who are White (IRR: 1.71, 95% CI: 1.48-1.98, P < .001), and was impacted by age at diagnosis, with Black-to-White incidence highest in children ages 5-9 years (IRR: 3.43, 95% CI: 2.36-4.94, P < .001). Overall survival was lower for males (HR: 1.39, 95% CI: 1.07-1.79, P = .013). All age groups, excluding those over 40, had improved survival compared to ages 0-4 years. Those who received surgical intervention had better survival compared to those who did not receive surgical treatment.

Conclusion

PB incidence is highest among children and patients who are Black, and there may be a potential interaction between these factors. Survival is worse among males, young children, and elderly adults, and those who received no surgery. Comprehensive, population-based statistics provide critical information on PB characteristics that could be useful in impacting patient care and prognosis.

Management dilemmas in pineoblastoma recurrence diagnosed during pregnancy

Pineoblastoma is an extremely rare intracranial neoplasm, with increased risk of craniospinal metastasis. There is only one case reported in the literature who presented during pregnancy. Described here is a woman who presented at five months of gestation with recurrence of pineoblastoma, who had previously defaulted adjuvant therapy following surgical decompression. The challenges in the diagnosis and treatment of pineoblastoma and its effects on pregnancy are also discussed.

A rare case of extremely delayed osseous metastasis of pineoblastoma

Pineoblastoma is a rare, primitive, and malignant tumor arising from the parenchyma of the pineal gland. It typically metastasizes along the cerebral neural axis, with rare extraneural metastasis and even more rare intraosseous extraneural metastasis. A patient with pineoblastoma, initially treated with chemotherapy, presented 10 years after initial diagnosis with multiple osseous metastases including his pelvis, femur, and vertebrae, and is currently undergoing chemotherapy.

Outcome and prognostic features in paediatric pineoblastomas: analysis of cases from the Surveillance, Epidemiology, and End Results registry (1990-2007)

BACKGROUND

Paediatric pineoblastomas are rare central nervous system tumours. Patient and treatment factors associated with outcome are poorly defined and limited to small retrospective case series and single case reports.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) cancer registry, we investigated clinical and pathological factors associated with outcome in paediatric pineoblastomas. Paediatric patients (< 16 years old) with pineoblastomas diagnosed between 1990 and 2007 were identified from the SEER database. Kaplan-Meier survival analysis and Cox models were used to examine the effect of variables on overall survival. The variables analysed included patient's age at diagnosis, gender, race, tumour spread and size, surgical resection and the use of adjuvant radiotherapy.

RESULTS

Seventy-eight patients were identified from the database. Twelve patients were excluded as 11 had no surgery and one patient was excluded as the surgical status was unknown. Analysis of the remaining 66 patients revealed a median age at diagnosis of 5.5 years. Three patients underwent biopsy. Seventeen patients underwent full and partial resection, respectively. A further 46 patients underwent surgery the nature of which was not recorded. Thirty-nine patients (59.1%) received adjuvant radiotherapy. Eight patients (12.1%) had both surgery (full or partial resection) and radiotherapy. The median overall survival was 40.5 months. Univariate analysis demonstrated that older age at diagnosis was the only positive predictor of overall survival.

CONCLUSION

This study represents the largest analysis of paediatric pineoblastomas to date. The only clinically relevant prognostic factor was older age at diagnosis. The role of surgery and adjuvant radiotherapy on overall survival remains to be defined.

Microsurgical resection of pineal region tumors

The extensive variety of possible histologic subtypes makes it imperative to establish a tissue diagnosis in patients with pineal region tumors. Management decisions regarding adjuvant therapy, prognosis, and follow-up strategies vary with the histologic diagnosis. Specialized surgical and stereotactic techniques have evolved to provide the neurosurgeon with an array of safe and effective options for obtaining a tissue diagnosis. Advanced microsurgical techniques combined with improved preoperative management and postoperative critical care methods have made aggressive surgical resection a mainstay of management. Aggressive surgical resection has resulted in excellent long-term prognoses for nearly all patients with benign tumors and a large percentage of patients with malignant tumors. However, pineal region surgery remains fraught with potential pitfalls, and these favorable results are dependent on an advanced level of surgical expertise.

Twenty-seven cases of pineal parenchymal tumours of intermediate differentiation: mitotic count, Ki-67 labelling index and extent of resection predict prognosis

OBJECTIVE

Optimal grading and treatment of pineal parenchymal tumours of intermediate differentiation (PPTID) have not been established due to their rarity. After careful review of more than 500 pineal region tumours treated in our centre, 27 patients with PPTID were identified.

METHODS

Diagnoses were confirmed according to WHO classification and graded as suggested by Jouvet et al. The relationship between the WHO grade, histopathological characters, management and outcome was analysed.

RESULTS

The WHO grade did not demonstrate significant correlation with outcome. Mitotic count and Ki-67 labelling index (LI) were detected as prognostic factors. Stratification of patients by mitotic count and Ki-67 LI correlated significantly with overall survival and progression-free survival. All the patients underwent resection. Gross total resection (GTR) was achieved in 16/27 (59.3%) patients, subtotal resection in 6/27 (22.2%) patients and partial resection in 5/27 (18.5%) patients. Log rank test confirmed GTR correlated with significantly better survival. Adjuvant therapy had a tendency to correlate significantly with progression-free survival. Among the high-risk patients, 6/9 patients with residual tumour received radiotherapy and 50% (3/6) were free of local tumour recurrence. In the other three high-risk patients with residual tumour who did not receive adjuvant therapy, recurrence occurred early and Ki-67 LI predicted prognosis.

CONCLUSIONS

Risk evaluation combining mitotic count and Ki-67 LI predicts prognosis. Surgery is the most efficient management. GTR is related to better prognosis. If GTR is not achieved, adjuvant therapy might delay tumour progression or recurrence, especially in high-risk patients.

Complete regression of adult pineoblastoma following radiotherapy: A case report and review of the literature

Adult pineoblastomas (PBs) are rare central nervous system tumors. Little is known with regard to the clinical features and outcomes of adult PB, and optimal treatment strategies for adult PB remain to be determined. The current report describes a case of PB in a 46-year-old male, who presented with obstructive hydrocephalus due to a large pineal region mass. Considering the potential effect on quality of life, the patient underwent a partial resection. Postoperative radiotherapy, comprising prophylactic craniospinal irradiation at a dose of 34.2 Gy followed by a local 25.3-Gy 'boost' to the tumor site for a total dose of 59.5 Gy, resulted in the complete regression of the tumor without neurological deficits. The patient has remained free of recurrence for 36 months after radiotherapy. This case highlights a minimally invasive strategy to treat a rare pineal region tumor with significant involvement of critical structures that resulted in a favorable response and an excellent neurological outcome. The radiographic and histopathological features of PB are also reviewed, and the various treatment options reported in the literature are discussed.

Clinical, Pathological, and Surgical Outcomes for Adult Pineoblastomas

INTRODUCTION

Pineoblastomas are uncommon primitive neuroectodermal tumors that occur mostly in children; they are exceedingly rare in adults. Few published reports have compared the various aspects of these tumors between adults and children.

METHODS

The authors report a series of 12 pineoblastomas in adults from 2 institutions over 24 years. The clinical, radiologic, and pathologic features and clinical outcomes were compared with previously reported cases in children and adults.

RESULTS

Patient age ranged from 24 to 81 years, and all but 1 patient exhibited symptoms of obstructive hydrocephalus. Three patients underwent gross total resection, and subtotal resection was performed in 3 patients. Diagnostic biopsy specimens were obtained in an additional 6 patients. Pathologically, the tumors had the classical morphologic and immunohistochemical features of pineoblastomas. Postoperatively, 10 patients received radiotherapy, and 5 patients received chemotherapy. Compared with previously reported cases, several differences were noted in clinical outcomes. Of the 12 patients, only 5 (42%) died of their disease (average length of survival, 118 months); 5 patients (42%) are alive with no evidence of disease (average length of follow-up, 92 months). One patient died of unrelated causes, and one was lost to follow-up. Patients with subtotal resections or diagnostic biopsies did not suffer a worse prognosis. Of the 9 patients with biopsy or subtotal resection, 4 are alive, 4 died of their disease, and 1 died of an unrelated hemorrhagic cerebral infarction.

CONCLUSIONS

Although this series is small, the data suggest that pineoblastomas in adults have a less aggressive clinical course than in children.

Pineal lesions: a multidisciplinary challenge

The pineal region is a complex anatomical compartment, harbouring the pineal gland surrounded by the quadrigeminal plate and the confluents of the internal cerebral veins to form the vein of Galen. The complexity of lesions in that region, however, goes far beyond the pineal parenchyma proper. Originating in the pineal gland, there are not only benign cysts but also numerous different tumour types. In addition, lesions such as tectal gliomas, tentorial meningiomas and choroid plexus papillomas arise from the surrounding structures, occupying that regions. Furthermore, the area has an affinity for metastatic lesions. Vascular lesions complete the spectrum mainly as small tectal arteriovenous malformations or cavernous haemangiomas.Taken together, there is a wide spectrum of lesions, many unique to that region, which call for a multidisciplinary approach. The limited access and anatomical complexity have generated a spectrum of anatomical approaches and raised the interest for neuroendoscopic approaches. Equally complex is the spectrum of treatment modalities such as microsurgery as the main option but stereotactic radiosurgery as an alternative or adjuvant to surgery for selected cases, radiation as for germinoma (see below) and or combinatorial chemotherapy, which may need to precede any other ablative technique as constituents.In this context, we review the current literature and our own series to obtain a snapshot sentiment of how to approach pineal lesions, how to interrelate alternative/competing concepts and review the recent technological advances.

Adults with CNS primitive neuroectodermal tumors/pineoblastomas: results of multimodal treatment according to the pediatric HIT 2000 protocol

Central nervous system primitive neuroectodermal tumors (CNS-PNET) and pineoblastomas (PBL) are rare in adulthood. Knowledge on clinical outcome and the efficacy and toxicities of chemotherapy in addition to radiotherapy is limited. Patients older than 21 years at diagnosis were followed in the observational arm of the prospective pediatric multicenter trial HIT 2000. After surgery, craniospinal irradiation and maintenance or sandwich chemotherapy were recommended. Radiotherapy was normo- (35.2 Gy; tumor region, 55.0 Gy; metastasis, 49.6 Gy) or hyperfractionated (40.0 Gy; tumor bed, 68.0 Gy; metastasis, 50-60 Gy). Maintenance chemotherapy consisted of eight courses (vincristine, lomustine, cisplatin). Sandwich chemotherapy included two cycles of postoperative chemotherapy followed by radiotherapy, and four courses of maintenance chemotherapy. Seventeen patients (CNS-PNET, n = 7; PBL, n = 10), median age 30 years, were included. Eight patients had a postoperative residual tumor and four patients metastatic disease. The median follow-up of ten surviving patients was 41 months. The estimated rates for 3-year progression-free survival (PFS) and overall survival were 68 ± 12 and 66 ± 13%, respectively. PBL compared to CNS-PNET tended towards a better PFS, although the difference was not clear (p = 0.101). Both chemotherapeutic (maintenance, n = 6; sandwich, n = 8) protocols did not differ in their PFS and were feasible with acceptable toxicities. Intensified regimens of combined chemo- and radiotherapy are generally feasible in adults with CNS-PNET/PBL. The impact of intensified chemotherapy on survival should be further assessed.

Technique, outcomes, and acute toxicities in adults treated with proton beam craniospinal irradiation

BACKGROUND

Proton craniospinal irradiation (p-CSI) has been proposed to reduce side effects associated with CSI. We evaluated acute toxicities and preliminary clinical outcomes in a series of adults treated with p-CSI.

METHODS

We reviewed medical records for 50 patients (aged 16-63 y) with malignancies of varying histologies treated consecutively with vertebral body-sparing p-CSI at MD Anderson Cancer Center from 2007 to 2011. Median CSI and total boost doses were 30.6 and 54 Gy. Forty patients received chemotherapy, varying by histology. Median follow-up was 20.1 months (range, 0.3-59).

RESULTS

Median doses to the thyroid gland, pituitary gland, hypothalamus, and cochleae were 0.003 Gy-relative biological effectiveness (RBE; range, 0.001-8.5), 36.1 Gy-RBE (22.5-53.0), 37.1 Gy-RBE (22.3-54.4), and 33.9 Gy-RBE (22.2-52.4), respectively. Median percent weight loss during CSI was 1.6% (range, 10% weight loss to 14% weight gain). Mild nausea/vomiting was common (grade 1 = 46%, grade 2 = 20%); however, only 5 patients experienced grade ≥2 anorexia (weight loss >5% baseline weight). Median percent baseline white blood cells, hemoglobin, and platelets at nadir were 52% (range, 13%-100%), 97% (65%-112%), and 61% (10%-270%), respectively. Four patients developed grade ≥3 cytopenias. Overall and progression-free survival rates were 96% and 82%, respectively, at 2 years and 84% and 68% at 5 years.

CONCLUSIONS

This large series of patients treated with p-CSI confirms low rates of acute toxicity, consistent with dosimetric models. Vertebral body-sparing p-CSI is feasible and should be considered as a way to reduce acute gastrointestinal and hematologic toxicity in adults requiring CSI.

Clinicopathologic study of pineal parenchymal tumors of intermediate differentiation

OBJECTIVE

Pineal parenchymal tumors of intermediate differentiation (PPTID) are extremely rare tumor entities, and only limited data are available regarding their pathologic features and biologic behaviors. Because grading criteria of pineal parenchymal tumors (PPTs) have yet to be established, the treatment strategy and prognosis of PPTIDs remain controversial. We describe the clinicopathologic study of six patients with PPTID and compare responses for the treatment and prognosis with cases of pineocytoma (PC) and pineoblastoma (PB). From this analysis, we attempt to clarify the treatment strategy for PPTIDs.

METHODS

This study included 15 patients with PPTs, consisting of 6 PCs, 6 PPTIDs, and 3 PBs. We focused on the 6 patients with PPTIDs. All PPTID cases were treated surgically, and radiotherapy and chemotherapy were administered as adjuvant therapies in some cases. We have earlier reported the histopathologic study (Neuropathology 32:647-653, 2012). Briefly, we examined mitotic figures and necrosis by hematoxylin-eosin staining and immunohistochemical markers such as neuronal markers (synaptophysin, neurofilament (NF), and neuronal nuclear antigen), and an MIB-1 labeling index was determined.

RESULTS

In the PPTID cases, the extent of resection was variable and the recurrence rates among patients varied according to stage and treatment. All PC patients underwent total resection with no recurrence. All PB patients underwent resection and adjuvant therapy with radiotherapy and chemotherapy. There were no recurrences in patients with PC or PB. The results of histopathologic findings have been already reported as mentioned above. Briefly, the results indicated no mitotic figure or necrosis in any of the six cases of PPTID, but those features were observed in PB cases. All cases even including PC and PB were immunopositive for neuronal markers. The MIB-1 labeling index of PPTID was 3.5%, whereas it was 0% in PC and 10.5% in PB.

CONCLUSIONS

Good radiosensitivity of PPTIDs was observed in our series. Because there are cases with discrepancies between images and pathologic findings, it is very difficult to determine the proper treatment strategy for PPTIDs. Proliferative potential was correlated with World Health Organization grade, although the immunoreactivity of neuronal markers did not correlate with the histologic grade.

Contrast-enhanced MR imaging in neuroimaging

MR imaging without and with gadolinium-based contrast agents (GBCAs) is an important imaging tool for defining normal anatomy and characteristics of lesions. GBCAs have been used in contrast-enhanced MR imaging in defining and characterizing lesions of the central nervous system for more than 20 years. The combination of unenhanced and GBCA-enhanced MR imaging is the clinical gold standard for the noninvasive detection and delineation of most intracranial and spinal lesions. MR imaging has a high predictive value that rules out neoplasm and most inflammatory and demyelinating processes of the central nervous system.

Primary pineal tumors: outcome and prognostic factors--a study from the Rare Cancer Network (RCN)

PURPOSE

To better define outcome and prognostic factors in primary pineal tumors.

MATERIALS AND METHODS

Thirty-five consecutive patients from seven academic centers of the Rare Cancer Network diagnosed between 1988 and 2006 were included. Median age was 36 years. Surgical resection consisted of biopsy in 12 cases and resection in 21 (2 cases with unknown resection). All patients underwent radiotherapy and 12 patients received also chemotherapy.

RESULTS

Histological subtypes were pineoblastoma (PNB) in 21 patients, pineocytoma (PC) in 8 patients and pineocytoma with intermediate differentiation in 6 patients. Six patients with PNB had evidence of spinal seeding. Fifteen patients relapsed (14 PNB and 1 PC) with PNB cases at higher risk (p = 0.031). Median survival time was not reached. Median disease-free survival was 82 months (CI 50 % 28-275). In univariate analysis, age younger than 36 years was an unfavorable prognostic factor (p = 0.003). Patients with metastases at diagnosis had poorer survival (p = 0.048). Late side effects related to radiotherapy were dementia, leukoencephalopathy or memory loss in seven cases, occipital ischemia in one, and grade 3 seizures in two cases. Side effects related to chemotherapy were grade 3-4 leucopenia in five cases, grade 4 thrombocytopenia in three cases, grade 2 anemia in two cases, grade 4 pancytopenia in one case, grade 4 vomiting in one case and renal failure in one case.

CONCLUSIONS

Age and dissemination at diagnosis influenced survival in our series. The prevalence of chronic toxicity suggests that new adjuvant strategies are advisable.

Outcome and prognostic features in adult pineoblastomas: analysis of cases from the SEER database

BACKGROUND

Adult pineoblastomas (PBL) are rare central nervous system tumors. Patient and treatment factors associated with outcome are poorly defined and limited to small retrospective case series and single case reports. Using the Surveillance, Epidemiology, and End Results (SEER) cancer registry, we investigated clinicopathological factors associated with outcome in adult PBL.

METHODS

Adult patients (≥16 years old) with PBL diagnosed between 1990 and 2007 were identified from the SEER database. Kaplan-Meier survival analysis and Cox models were used to examine the effect of variables on overall survival. The variables analyzed included patient's age at diagnosis, gender, race, tumor location, uni-focal or multi-focal tumor, tumor size, surgical resection, and the use of adjuvant radiotherapy.

RESULTS

Ninety-five patients were identified, with a median age at diagnosis of 39.2 years. Sixty-one patients (64 %) underwent surgery and 44 patients (47.4 %) received adjuvant radiotherapy. Forty-two patients (44 %) had both surgery and radiotherapy. The median overall survival was 176 months. Univariate analysis identified younger age at diagnosis, uni-focal and localized disease as important predictors of overall survival. On multivariate analysis, only age at diagnosis and localized disease emerged as important prognostic factors.

CONCLUSIONS

Despite the numerous limitations of the SEER database, this study represents the largest analysis of adult PBL to date. Clinically relevant prognostic factors were younger age of diagnosis and localized disease. The role of surgery and adjuvant radiotherapy remains to be defined. Our data suggest these treatment modalities may not influence overall survival.

Distinguishing between germinomas and pineal cell tumors on MR imaging

BACKGROUND AND PURPOSE

Tumors of pineal cell origin have different prognosis and treatment than those of germ cell origin. The recent literature suggests that these tumors often look alike. Our study aimed to differentiate between pineal cell tumor and germinoma based on ADC values, the homogeneity of the mass, and MR imaging characteristics.

MATERIALS AND METHODS

We enrolled 20 patients who had pretreatment MR imaging scans with histologic verification of tumors of pineal cell origin and germinomas. The tumors were measured for the ADC values and for homogeneity by the coefficient of variation of ADC values, and T1WI and T2WI signal intensity values.

RESULTS

The 20 subjects (8 females and 12 males) ranged in age from 1.5-64.9 years, with a mean age of 23.9 years (SD 17.7 years). The mean age of those with germinomas was 13.7 years (SD 3.8 years), less than the mean of 29.4 years for those with pineal cell tumors (SD 19.9 years; P = .016). These 2 groups showed no significant difference in coefficients of variation on T1WI, T2WI, and ADC images. However, germinomas showed statistically significant higher ADC values (mean 1590.69 ± 532.96 × 10(-6) mm(2)/s) than pineal cell tumors (mean 883.58 ± 317.48 × 10(-6) mm(2)/s; P = .02). An accuracy of 89.5%, sensitivity of 83.3%, specificity of 92.3%, PPV of 83.3%, and NPV of 92.3% were yielded for an ADC threshold of 1250.00 × 10(-6) mm(2)/s.

CONCLUSIONS

Germinomas showed higher ADC values than the pineal cell tumors (P = .02), and the patients were younger. Otherwise, there were no definitive imaging characteristics that distinguished pineal cell tumors from germinomas.

The long-term postsurgical prognosis of patients with pineoblastoma

BACKGROUND

For this report, the authors comprehensively summarized the existing literature on patients with pineoblastoma and identified the variables and treatments that had an impact patient on outcomes.

METHODS

A comprehensive search identified 109 studies that collectively described the outcomes of patients with pineoblastoma. Individual patient data were classified based on treatment and were subjected to univariate comparisons. Cox regression analysis included comparisons of survival outcomes controlling for age, extent of resection, and treatment group, and between-group survival comparisons were performed using the Kendall tau (rank correlation) statistic.

RESULTS

Two hundred ninety-nine patients met inclusion criteria. The overall survival rate was 54% (175 of 299 patients) at a mean follow-up of 31 ± 1.9 months (range, 1-159 months). The analyses demonstrated a markedly worse prognosis for children aged ≤ 5 years compared with older patients (5-year survival rate: 15% for children aged ≤ 5 years vs 57% for children aged ≥ 5 years; log-rank P < .00001). In addition, a graded increase in survival was observed with increasing degrees of resection (5-year survival rate: 84% for patients who underwent gross total resection vs 53% for patients who underwent subtotal resection vs 29% for patients who underwent debulking; log-rank P < .0001). Multivariate analysis indicated that not achieving gross total resection markedly worsened patient survival (subtotal resection: hazard ratio, 6.47; 95% confidence interval, 2.3-19; P = .001. debulking: hazard ratio, 9.27; 95% confidence interval, 3.2-27; P < .0001).

CONCLUSIONS

The current findings emphasize the importance of aggressive surgical resection in the treatment of pineoblastoma. In addition, the authors conclude that clinical trials should not mix young patients with older patients or patients who undergo subtotal resection with patients who undergo gross total resection, because such heterogeneity may alter the variability of responses to treatment and reduce the likelihood of success.

Contemporary management of pineoblastoma

Pineoblastomas (PBs) represent the most aggressive of the pineal parenchymal tumors. Routine treatment consists of operative management of obstructive hydrocephalus and cerebrospinal fluid studies followed by maximal resection and adjuvant chemotherapy/radiotherapy, resulting in a median survival of 20 months. Important prognostic factors for survival of patients with PB include extent of resection, age at presentation, disseminated disease, and craniospinal radiotherapy. Novel strategies being evaluated for the treatment of PB include high-dose chemotherapy with autologous stem cell therapy, stereotactic radiosurgery, and histone deacetylase inhibitors.

Pathology of pineal parenchymal tumors

Tumors of the pineal region can arise from multiple cellular origins and thus represent a very heterogeneous group of pathologies. Such tumors include pineal parenchymal tumors, germ cell tumors, astrocytomas, ependymomas, and papillary pineal tumors. Within the subgroup of pineal parenchymal tumors, there is a histopathologic spectrum ranging from pineocytoma to pineal parenchymal tumors of intermediate differentiation to pineoblastoma. The current World Health Organization classification and the pathologic features of each of the pineal parenchymal tumor subtypes are reviewed in this article.

Pineal tumors

Pineal tumors are a rare and heterogeneous group of primary central nervous system neoplasms, including pineal parenchymal tumors (pineocytomas, pineal parenchymal tumors of intermediate differentiation, and pineoblastomas), germ cell tumors, and neuroepithelial tumors, such as astrocytomas, ependymomas, and papillary tumor of the pineal region. Their classification has evolved over time, with several updates incorporated into the most recent World Health Organization classification, published in 2007. This review highlights the most recent classification and grading scheme for pineal parenchymal tumors and discusses the newly recognized papillary tumor of the pineal region, including clinicopathologic features, differential diagnosis, and management options.

Pineal parenchymal tumors. Management with interstitial iodine-125 radiosurgery

PURPOSE

To evaluate the efficacy of interstitial radiosurgery (IRS) for pineal parenchymal tumors (PPTs).

PATIENTS AND METHODS

18 consecutively admitted patients (twelve male and six female, age range 6-68 years, median age 34 years) with PPTs (eight pineocytomas, ten malignant PPTs) were treated at the authors' institution with IRS using stereotactically guided iodine-125 seed implantation ((125)I-IRS) as either primary or salvage therapy. The cumulative tumor surface dose ranged from 40 to 64 Gy. Adjuvant radiotherapy of the whole brain or the craniospine was done in patients with grade III and grade IV PPT. The median follow-up period was 57.4 months (range 6-134 months).

RESULTS

Overall actuarial 5- and 8-year survival rates after IRS were 100% and 86% for pineocytomas, and the overall actuarial 5-year survival rate was 78% for high-grade PPTs. Follow-up magnetic resonance imaging showed complete remission in 72% (13/18) and partial remission in 28% (5/18) of the cases. One patient developed an out-of-field relapse 4 years after partial remission of a pineocytoma, which had already been treated with IRS. There was no treatment-related mortality. Treatment-related morbidity occurred in two patients only.

CONCLUSION

This study indicates that stereotactic (125)I-IRS for the management of PPTs is quite efficient and safe. Due to the low rate of side effects, IRS may develop into an attractive alternative to microsurgery in de novo diagnosed pineocytomas. In malignant PPTs, IRS may be routinely applied in a multimodality treatment schedule supplementary to conventional irradiation.

Pinealoblastoma with prominent retinoblastic differentiation: an unusual case in an adult

We present an extremely rare case of pinealoblastoma with retinoblastic differentiation in a 32-year-old woman who presented with a history of intermittent headache of 2 years duration and diminution of vision for 2 months which eventually lead to total loss of vision. The fundus examination showed bilateral secondary optic atrophy. She did not have any previous history of retinoblastoma. The family history was non-contributory. Paraffin section of the tumor showed a primitive neuroectodermal tumor with numerous Flexner-Wintersteiner rosettes and the tumor cells were strongly positive for synaptophysin and negative for GFAP, S-100 protein and epithelial membrane antigen. This is the first case in the literature of a sporadic case of pinealoblastoma with prominent retinoblastic differentiation as evidenced histomorphologically by the presence of numerous Flexner-Wintersteiner rosettes in an adult female.

Post-radiation reactive changes in a single vertebral body mimicking metastatic pineoblastoma

This 18-year-old woman presented with headache and diplopia over several months and was found to have an enhancing pineal tumor with resultant obstructive hydrocephalus. Following standard preoperative diagnostic tests, including spinal axis imaging, the patient was taken to the operating room for an endoscopic third ventriculostomy to relieve hydrocephalus and then subsequently underwent a craniotomy for gross-total resection of the pineal mass. The patient was discharged after an uneventful hospital course and received standard adjuvant cranial-spinal radiation and chemotherapy as an outpatient. Follow-up imaging 1 year after surgery demonstrated a metabolically active, lytic lesion in the C-3 vertebral body and new lung lesions suggesting a metastatic pineoblastoma. The patient underwent a C-3 anterior corpectomy and reconstruction without complication as aggressive therapy for presumed metastatic disease. Final pathological results from the vertebral lesion were consistent with radiation-induced reactive changes, not metastatic pineoblastoma as originally suspected. The patient recovered well and remains symptom free. To the authors' knowledge this is the first reported case of reactive changes mimicking metastasis in a single vertebral body following standard therapy for resected primary pineoblastoma.

INTRAOPERATIVE DIRECT THIRD VENTRICULOSTOMY AND AQUEDUCTAL STENTING IN DEEP-SEATED MIDLINE BRAIN TUMOR SURGERY

OBJECTIVE

Surgical resection of deep-seated midline brain tumors does not always resolve obstruction of cerebrospinal fluid pathways, and an additional operation—ventricular shunting—is required. To prevent postoperative obstructive hydrocephalus, we combine tumor removal and internal ventricular shunting in 1 stage.

METHODS

Between 2000 and 2006, 82 patients with deep-seated midline brain tumors (tumors of the third ventricle, pineal region, thalamus, upper brainstem, and superior half of the fourth ventricle) underwent 84 tumor resections with intraoperative internal ventricular shunting. Two types of intraoperative shunting were performed: direct third ventriculostomy with fenestration of the premammillary membrane of the third ventricle floor and Liliequist's membrane, 53 operations; and aqueductal stenting, 30 operations. In 1 patient, third ventriculostomy and aqueductal stenting were performed simultaneously.

RESULTS

As most of the tumors had an infiltrative growth pattern, gross total tumor removal was achieved in only 31% of patients in this series. There were no fatal outcomes related to the surgery. Follow-up data were collected in 73 patients (89%) and ranged from 2 to 68 months (median, 16 months). Additional shunting because of inadequate function of stoma or stent was performed in 13 patients at various times after surgery (median, 30 days). The Kaplan-Meier survival analysis demonstrated that at 12 and 24 months the intraoperative direct third ventriculostomy success rates were 67 and 61%, respectively; aqueductal stenting success rates were 93% at both 12 and 24 months.

CONCLUSION

Intraoperative direct third ventriculostomy and aqueductal stenting under direct visual control were found to be reliable methods of hydrocephalus management in patients with deep-seated midline brain tumors.

Management of pineal region tumors

Tumors of the pineal region represent a diverse collection of tumors with a variety of natural histories. This diversity necessitates accurate histologic diagnosis to allow rational therapeutic planning. Evaluation of a pineal lesion should begin with craniospinal MRI and analysis of the cerebrospinal fluid (CSF). Whereas certainty of the histologic diagnosis is now a requirement for treatment in Western nations, some Asian centers continue to recommend a test dose of radiation therapy based on the high incidence of germinoma in those countries. If there is high clinical suspicion of a germinoma or tectal glioma, stereotactic or endoscopic biopsy may be pursued. All other lesions should be referred for open biopsy with microsurgical techniques. This approach provides adequate tissue for diagnosis, may be curative in low-grade tumors, and may substantially improve survival in patients with malignant tumors. If open surgery is not desired by the patient or practitioner, stereotactic or endoscopic biopsy may be followed by radiosurgery for localized, well-demarcated tumors. Radiation therapy is the first-line therapy for germinomas. Although the optimal radiation dosage and volume have not been decided, the current Children's Oncology Group trial may offer definitive evidence to address this dilemma in germ cell tumors. Evidence of CSF seeding requires craniospinal radiation and adjuvant chemotherapy regardless of tumor type. Diagnosis of any of the malignant tumors (non-germ cell tumors, pineoblastomas, and parenchymal tumors of intermediate determination) also requires craniospinal radiation (with local tumor doses of at least 50 Gy) and adjuvant chemotherapy (generally platinum based). Patients with tectal gliomas may undergo excision with or without postoperative radiation; however, they also may be observed with vigilant follow-up alone.

Postoperative adjuvant treatment for pineal parenchymal tumour of intermediate differentiation

Pineal parenchymal tumour of intermediate differentiation (PPTID) in adults is rare and a treatment strategy for this condition has not yet been established. We present a case of an elderly patient treated with postoperative adjuvant therapy using radio- and chemotherapy. This 60-year-old man presented with a 3-month history of memory disturbance, gait instability and double vision. Computed tomography and magnetic resonance imaging demonstrated a mass in the pineal region that suggested a malignant tumour. Partial removal of the tumour was undertaken via the right occipital transtentorial approach. The histological diagnosis was PPTID. Postoperative radio- and chemotherapy were administered, with a good response. Little is known about the clinical behaviour of PPTID in adults. Our treatment plan indicates one effective option for the management of such tumours.

Pineal parenchymal tumors of intermediate differentiation in adults: Case report and literature review

Pineal parenchymal tumors (PPT), including pineoblastomas, are very uncommon, especially in adults. Because of the small number of reported cases, the histological and biological features of these tumors are still being defined, as is their optimal management. Also, the pathological variability of these tumors makes it difficult to draw general conclusions about their behavior. We report the case of a PPT of intermediate differentiation (PPTID) with an excellent outcome. A 3.2 cm tumor in the pineal and tectal region with obstructive hydrocephalus was found in a 28-year-old female complaining of headaches and hypoesthesia of the right side of the face. Stereotactic biopsy revealed a highly cellular tumor composed of small cells that contained little cytoplasm that were arranged in a diffuse pattern. Mitotic activity was low and there was no evidence of necrosis. Immunohistochemical examination demonstrated positive staining for neuron-specific enolase and synaptophysin. There was no expression of neurofilaments or GFAP. Ki-67 proliferation index was 12%. The diagnosis was a PPTID. Treatment consisted of combined neoadjuvant chemotherapy and craniospinal radiotherapy. Six years after treatment, the patient is alive and free of any clinical or radiological signs of relapse. This paper discusses the pathological and biological features of these tumors and the treatment options available.

The role of Gamma Knife radiosurgery in the treatment of pineal parenchymal tumours

OBJECT

The aim of this study was to document the possible role of Gamma Knife radiosurgery, suitable for the treatment of deep and well limited tumors, in the management of pineal parenchymal tumors (PPT).

POPULATION AND METHODS

We reviewed retrospectively a series of 13 patients with PPT treated by Gamma Knife radiosurgery during 16 procedures. Mean age was 31 (range 10 to 74). Eight patients had pineocytomas (61.5%), and 5 had pineoblastomas (38.5%). Radiosurgery was performed alone in 6 cases, after partial microsurgical resection in 3 cases, in association with chemotherapy in 3 cases and following conventional fractionated radiotherapy in 1 case. The marginal dose to these tumors ranged from 11 to 20 Gy (mean 15 Gy).

RESULTS

With a mean follow-up of 34 months (range 6 to 88), all tumors responded to treatment and disappeared or ceased growing. Two patients with pineoblastoma had tumor size progression out of the initial target requiring several radiosurgery procedures. At the end of the follow-up period, 10 out of 12 patients were alive. Two patients with pineoblastoma died because of carcinomatous meningitis or tumor size progression. We observed no mortality or major morbidity related to radiosurgery.

CONCLUSION

This study confirms that radiosurgery can be an effective and safe primary treatment modality for patients with pineocytomas. It should have a role in multimodality therapy which includes microsurgical resection, fractionated radiotherapy and chemotherapy for the management of malignant pineal tumors.

High-dose chemotherapy with autologous stem-cell rescue in children and adults with newly diagnosed pineoblastomas

PURPOSE

We evaluated the usefulness of a treatment regimen that included high-dose chemotherapy (HDC) with autologous stem-cell rescue (ASCR) in patients with newly diagnosed pineoblastoma (PBL).

PATIENTS AND METHODS

Twelve patients with PBL were initially treated with surgery and induction chemotherapy. All but two patients underwent radiotherapy. Subsequently, all patients received HDC using cyclophosphamide (CTX) + melphalan (MEL) or busulfan (Bu) + MEL regimens and ASCR.

RESULTS

A total of six children and six adults with median ages of 4.2 (range, 0.3 to 19.8 years) and 23 years (range, 23 to 43.7 years), respectively, were treated according to this strategy. Four patients had metastatic disease confined to the neuraxis. Five of 12 patients (42%) had a complete tumor resection at diagnosis. Ten patients received radiotherapy at median doses of 36.0 and 59.4 Gy to the neuraxis and pineal region, respectively. Eleven patients received HDC with CTX + MEL, and one patient received BU + MEL followed by ASCR. Nine patients are alive with no evidence of disease recurrence at a median of 62 months from diagnosis (range, 28 to 125 months), including three patients with metastatic disease and two infants who did not receive any radiotherapy. Three patients have died of progressive disease at 19, 32, and 37 months from diagnosis, respectively. The actuarial 4-year progression-free and overall survivals are 69% (95% confidence interval [CI], 39% to 99%) and 71% (95% CI, 43% to 99%), respectively.

CONCLUSION

The use of HDC in addition to radiotherapy seems to be an effective treatment for patients with newly diagnosed pineoblastoma.

Principles of treatment of the pineal region tumors

BACKGROUND

A pineal region tumor is an uncommon deep-seated, heterogeneous group of mass lesions of the brain, and the management strategy of any types of these tumors remains controversial. It is the purpose of this communication to present results of our experience in treating patients with these neoplasms.

METHODS

From 1976 to 1999 about 700 patients with tumors of the pineal region and posterior third ventricle were managed at the Burdenko Neurosurgery Institute. In more than 330 cases the tumor was removed. In this paper we present results of 287 patients with histologically verified pineal region tumors for the period from 1976 to 1999. All of them had verified tumor histology, excluding only five cases in which stereotactic biopsy procedures were uninformative. There are four main groups of tumors: the germ cell tumors-87 (31%); the pineal parenchymal tumors-75 (27%); the glial tumors-77 (27%); and miscellaneous-43 (15%). There were 255 surgical procedures for tumor removal performed in 244 and stereotactically guided biopsies in 61 patients, 168 (58%) with obstructive hydrocephalus who underwent cerebrospinal fluid shunting. Radiation therapy was administered in 145 (51%) and chemotherapy in 16 patients. Follow-up data were collected in 209 cases (80%). Survival was calculated with the Kaplan-Meier product limit method.

RESULTS

The occipital transtentorial and infratentorial supracerebellar approaches were the most commonly used on our series-138 (54%) and 87 (34%), respectively. In the remaining cases, subchoroidal approach, approach through the fourth ventricle, and the combined approaches were used. A total tumor removal was achieved in 148 operations (58%), subtotal in 74 (29%) and partial in 33 (13%). The projected 5-year and 10-year survival rates for patients with malignant pineal tumors, who received irradiation after tumor resection or underwent radiation therapy alone, were: 95% and 88% for pure germinomas, 80% and 50% for high grade gliomas, 44% and 0% for malignant pineal parenchymal tumors, and 20% and 0% for malignant germ cell tumors, respectively.

CONCLUSIONS

Benign pineal tumors should be cured with surgery alone. Malignant tumors should be treated with aggressive resection followed with irradiation and chemotherapy. Pure germinomas, which are exquisitely radiosensitive, can be cured by conventional radiation therapy alone.

The role of radiosurgery for the treatment of pineal parenchymal tumors

OBJECTIVE

Radiosurgery is an appealing alternative management strategy for selected patients with biopsy-proved pineal parenchymal tumors. The purpose of this report was to clarify its role in conjunction with other surgical, radiation, and medical approaches.

METHODS

We retrospectively evaluated 16 patients who had undergone radiosurgery as the primary or adjuvant treatment for pineal parenchymal tumors. Ten patients (62.5%) had pineocytomas, two (12.5%) had mixed pineocytoma and pineoblastoma, and four (25%) had pineoblastomas. The mean marginal dose was 15 Gy, and the mean tumor volume was 5.0 cm(3). The mean follow-up periods from the time of diagnosis or the time of radiosurgery were 61 and 52 months, respectively.

RESULTS

The overall actuarial 2- and 5-year survival rates after diagnosis were 75.0 and 66.7%, respectively. In 14 patients who were evaluated with imaging, 4 (29%) demonstrated complete remission, 8 (57%) had partial remission, 2 (14%) had no change, and no patient had local progression. The local tumor control rate (complete remission, partial remission, or no change) was 100%. Five patients died during follow-up. One patient with a pineocytoma and three patients with pineoblastomas died secondary to leptomeningeal or extracranial spread tumor. No cause of death was established for one patient. Two patients developed adverse radiation effects after radiosurgery.

CONCLUSION

Our initial experience suggests that stereotactic radiosurgery is a valuable primary management modality for patients with pineocytomas. As adjuvant therapy, radiosurgery may be used to boost local tumor dose during multimodality management of malignant pineal parenchymal tumors.

Malignant pineal parenchymal tumors in adult patients: patterns of care and prognostic factors

OBJECTIVE

The aim of our study was to analyze patterns of care and to identify prognostic factors in patients at least 18 years of age who received radiotherapy for malignant pineal parenchymal tumors.

METHODS

In a multicenter, retrospective study, we analyzed data for 37 previously published cases and 64 patients treated at the participating institutions.

RESULTS

A total of 56 patients received postoperative radiotherapy, and 45 patients received primary radiotherapy. Chemotherapy was administered to 34 patients. The median follow-up period was 38 months, and median overall survival was 100 months. The variables that significantly influenced overall survival were the extent of disease (localized versus disseminated; P = 0.0002), differentiation (pineal parenchymal tumor of intermediate differentiation versus pineoblastoma; P = 0.001), and residual disease (> or = 50% versus < 50% reduction in size; P < 0.0001). In a multivariate analysis, the parameters turned out to be independent risk factors. The median survival in patients with local or spinal failure was 15 months. Local control was better in older patients (> or = 32 yr versus < 32 yr; P = 0.02). Spinal control was more successful in patients with pineal parenchymal tumors of intermediate differentiation than it was in patients with pineoblastomas (P = 0.03). Nine of 45 treatment failures occurred later than 5 years after treatment.

CONCLUSION

Stage, histological characteristics, and response are independent risk factors in adults with malignant pineal parenchymal tumors. Late relapses are common.

Vertebral metastases from pineoblastoma

Two male patients aged 26 and 18 years presented with vertebral metastases originating from pineoblastomas on which surgery had been performed 8 years and 5 months earlier, respectively. In the first case in which the metastasis developed in the T8 corpus, the disease is presently under control after high-dose chemotherapy and autologous blood stem cell transplantation. The second patient (sacral metastasis), despite aggressive adjuvant therapy, died 2 years after the last operation because of spinal seeding. These uncommon cases are discussed with reference to the literature on extraneural metastases that originate from neuroepithelial tumors of the central nervous system.

Clinicopathological study of pineal parenchymal tumors: correlation between histopathological features, proliferative potential, and prognosis

This study describes the clinicopathologic features of 13 cases with pineal parenchymal tumors. Based on the histopathologic findings, especially the extent of atypia and pineocytic differentiation as determined by Bodian's staining, we classified these tumors into pineocytomas (4), pineocytomas with anaplasia (4) and pineoblastomas (5). All the cases with pineocytoma and pineocytoma with anaplasia were adults, and all the cases with pineoblastoma were younger children. One patient with pineocytoma died of other disease 7 months after initial treatment. One patient with pineocytoma with anaplasia died 168 months after initial treatment. The other patients with pineocytoma and pineocytoma with anaplasia survived between 9 and 179 months after surgery. However, all of the five pineoblastoma patients died within 14 months after initial treatment. The mean MIB-1 index in pineoblastomas was significantly higher than that in other types of pineal parenchymal tumors, but there were no differences between pineocytomas and pineocytomas with anaplasia with respect to the MIB-1 index. The mean MIB-1 index in neurofilament protein-immunopositive cases was significantly lower than that in immunonegative cases. With regard to the malignant potential, we emphasize that a clear distinction should be made between pineoblastomas in children and other types of pineal parenchymal tumors in adults.

Parenchymal pineal tumors: a clinicopathological study of 76 cases

PURPOSE

The aim of this study was to identify factors that could lead to optimization of the management of pineal parenchymal tumors (PPT) which remains equivocal and controversial.

METHODS AND MATERIALS

In order to determine factors that influence PPT prognosis, a series of 76 consecutive patients from 12 European centers with histologically proven tumors was retrospectively reviewed. The clinical records and material for histologic review were available in all cases. Follow-up was achieved in 90% of cases.

RESULTS

According to WHO classification, there were 19 pineocytomas, 28 intermediate and mixed PPT, and 29 pineoblastomas. According to a four-grade institutional classification, there were 11 Grade 1, 27 Grade 2, 20 Grade 3, and 18 Grade 4. Surgical resection was attempted in 44 patients, whereas 30 had biopsy only. In one case, diagnosis was made at autopsy and in another on spinal deposits. Forty-four patients were irradiated following surgery, 15 patients received chemotherapy. Forty-one patients were alive (median follow-up: 85 months); 9 patients died perioperatively; 26 patients relapsed. Univariate analysis showed a good outcome correlated with age above 20 years, tumor diameter less than 25 mm, and low-grade histology. Multivariate analysis confirmed histology and tumor volume to be significant independent prognostic factors. The extent of surgery and radiotherapy had no clear influence on survival.

CONCLUSIONS

This review highlights the prognostic features of PPT and may help to determine treatment strategies based on radiologic and pathologic characteristics.