Cytopathological spectrum of peripheral neuroblastic tumours in fine needle aspiration cytology and categorisation as per International Neuroblastoma Pathology Classification.

OBJECTIVE: The aim of this analysis was to describe the cytopathology spectrum of peripheral neuroblastic tumours (NTs) including neuroblastoma (NB), ganglioneuroblastoma (GNB) and ganglioneuroma (GN). Feasibility of applying the International Neuroblastoma Pathology Classification (INPC) to further subtype NTs in cytology was evaluated. METHODS: All peripheral NTs reported on fine needle aspiration during 2011-2015 were retrieved and detailed cytomorphological evaluation was performed. Based on INPC criteria, NBs were further categorised as undifferentiated, poorly differentiated and differentiating subtypes. Mitotic-karyorrhectic index was evaluated. Immunocytochemistry on cell blocks was reviewed wherever available. MYCN amplification by fluorescence in situ hybridisation was performed in 11 cases on smears. RESULTS: A total of 90 cases including 83 NBs, six GNB and one GN were evaluated. The age range was 12 days-12 years, with 55 males and 45 females. Both the primary and metastatic locations were aspirated. Applying the INPC criteria, there were 61 poorly differentiated, 14 undifferentiated, eight differentiating NB and six GNB. Immunocytochemistry on cell blocks showed positivity for at least two neuronal markers in NB. Mitotic-karyorrhectic index was high in 63, low in 22 and intermediate in two cases, respectively. MYCN amplification by fluorescence in situ hybridisation was feasible on smears and was amplified in 6 out of 11 cases tested. CONCLUSION: Peripheral NT types including NB, GNB and GN have distinctive cytomorphology. NBs can be further subtyped as undifferentiated, poorly differentiated and differentiating subtypes as per INPC criteria.

Fine-needle aspiration of ganglioneuroma, maturing type (a.k.a., "borderline ganglioneuroblastoma") in the mediastinum of a young man: Case report and discussion of classification.

We report a very unusual case of a posterior mediastinal tumor in a young man, which we diagnosed by fine-needle aspiration cytology as most consistent with ganglioneuroma, maturing subtype. The cytopathologic features were interpreted using the classification of neuroblastic tumors as defined by the International Neuroblastoma Pathology Committee. Neuroblastic tumors are peculiar tumors that have capacity for maturation, and hence they present as a spectrum of tumors, ranging from the undifferentiated neuroblastoma, to ganglioneuroblastoma, to the mature version ganglioneuroma. The practicing surgical pathologist or cytopathologist who does not regularly encounter pediatric specimens may experience difficulty interpreting a specimen from one of these tumors. The following case report discusses application of these criteria to cytopathologic diagnosis of these tumors.

[Neurogenic tumors of the mediastinum in adults]. / Tumeurs nerveuses du médiastin de l'adulte.

In adults, mediastinal neurogenic tumours constitute the third group of mediastinal tumours, after thymomas and lymphomas. If the group of neurogenic tumour is frequent, each type of tumour is relatively unusual in everyday's clinic. Among them, nerve sheath tumours are the more frequent, followed by tumour of the autonomic system. Askin tumour remains uncommon. Treatment of this tumour requires complete preoperative work-up, including standard radiography, CT-scan, MRI, and sometimes nuclear imaging. In most cases, the treatment is based on surgical resection, and may be associated with radiotherapy or chemotherapy in case of malignant tumour or incomplete resection. Better understanding of these tumours, including their molecular abnormalities, may lead to new changes in their classifications, and to their management.

[Peripheral neuroblastic tumors: anatomo pathological classification]. / Les tumeurs neuroblastiques périphériques, classification anatomo-pathologique.

Peripheral Neuroblastic Tumors are classified according to the recommendations of the INPC into four categories and their subtypes: 1/Neuroblastoma stroma poor, undifferentiated, poorly differentiated, and differentiating, 2/ganglioneuroblastoma stroma composite, nodular, 3/ganglioneuroblastoma stroma composite, intermixed and 4/ganglioneuromas stroma dominant, maturing and mature. The classification is based on age and morphologic features of PNT, including the differentiation grade of the neuroblasts and the mitosis-karyorrhexis index. Histopathological classification has prognostic impact in predicting overall and event-free survival allowing the categorisation of PNT into two groups: favorable subset and unfavorable subset.

Revision of the International Neuroblastoma Pathology Classification: confirmation of favorable and unfavorable prognostic subsets in ganglioneuroblastoma, nodular.

BACKGROUND: Ganglioneuroblastoma, nodular (GNBn) comprises one of the categories of peripheral neuroblastic tumors. All tumors in this category, according to the original International Neuroblastoma Pathology Classification, are classified into an unfavorable histology group. Subsequently, it has been reported that GNBn can be divided into two prognostic subsets, a favorable subset (FS) and an unfavorable subset (US). METHODS: Histology slides from 70 patients who were enrolled in Children's Cancer Group studies 3881 and 3891 and who had a diagnosis of GNBn were reviewed jointly by the members of International Neuroblastoma Pathology Committee (INPC): 1) to confirm the diagnosis of GNBn, 2) to identify the FS and US by applying the same age-linked criteria that were used to distinguish the favorable histology group and unfavorable histology group in conventional neuroblastoma tumors from the neuroblastomatous component of GNBn tumors, and 3) to verify the significant prognostic difference between these two subsets. The patients had been used in a previous study, and survival data for the patients were updated since the time of their last report. RESULTS: The review clarified and illustrated morphologic characteristics of classical GNBn and it variants. The diagnosis of GNBn was confirmed in 67 of 70 patients. There were 22 patients with GNBn in the FS and 45 patients with GNBn in the US. The estimated survival differences between the FS and US patients with GNBn were statistically significant (8-year event free survival rate: 86.1% vs. 32.2%; P = 0.0003; overall survival rate: 90.5% vs. 33.2%; P = 0.0003). CONCLUSIONS: This study confirmed the recently defined prognostic subsets of GNBn. The INPC proposes to modify the International Neuroblastoma Pathology Classification by distinguishing the FS and the US among patients with GNBn tumors.

International neuroblastoma pathology classification for prognostic evaluation of patients with peripheral neuroblastic tumors: a report from the Children's Cancer Group.

BACKGROUND: The International Neuroblastoma Pathology Classification was established in 1999 for the prognostic evaluation of patients with neuroblastic tumors (NTs). METHODS: Pathology slides from 746 NTs (the Children's Cancer Group [CCG]-3881 and CCG-3891 studies) were evaluated according to the International Classification. First, prognostic effects of the morphologic indicators (grade of neuroblastic differentiation: undifferentiated [U], poorly differentiated [PD] and differentiating [D]; and mitosis-karyorrhexis index [MKI]: low [L-MKI], intermediate [I-MKI], and high [H-MKI]) for tumors in the neuroblastoma (NB) category were tested. Then, prognostic significance of the International Classification for all NTs in four categories (neuroblastoma [NB]; ganglioneuroblastoma, intermixed [GNBi]; ganglioneuroma [GN]; and ganglioneuroblastoma, nodular [GNBn]) was analyzed. Finally, age distribution of the patients in the four categories as well as three subtypes (based on the grade of differentiation) in the NB category was compared. RESULTS: There were 630 NB tumors, 30 GNBi tumors, 10 GN tumors, and 76 GNBn tumors. In the NB category, prognostic effects of the indicators (three grades of differentiation and three mitosis-karyorrhexis index [MKI] classes: low [L], intermediate [I], and high [H]) were affected significantly by the age of the patients. The age-linked evaluation of the indicators according to the International Classification successfully distinguished two prognostic subgroups: the favorable histology (FH) subgroup (PD/D and L/I-MKI tumors in patients age < 1.5 years, D and L-MKI tumors in patients ages 1.5-5.0 years; 90.4% 5-year event free survival [EFS]) and the unfavorable histology (UH) subgroup (U and/or H-MKI tumors in patients of any age, PD and/or I-MKI tumors in patients ages 1.5-5.0 years, any grade of differentiation, and any MKI class in patients age > or = 5 years; 26.9% EFS) (P < 0.0001). The International Classification also distinguished the FH group (FH subgroup with NB, GNBi, and GN tumors) and the UH group (UH subgroup with NB and GNBn tumors) for all NTs (90.8% EFS and 31.2% EFS, respectively; P < 0.0001) and provided independent prognostic information on both patient age and disease stage (P < 0.0001). Among patients with FH tumors, the median ages of patients with the PD and D subtype tumors in the NB category were 0.43 years (range, 0-1.50 years) and 1.50 years (range, 0.02-4.65 years), respectively, and the median ages of patients with GNBi and GN tumors were 3.51 years (range, 0.96-14.85 years) and 4.80 years (range, 1.94-17.05 years), respectively. In contrast, patients with UH tumors generally were older when they were diagnosed, and with median ages of 2.99 years (range, 1.30-8.84 years) for patients with U subtype tumors, 2.59 years (range, 0.0-12.57 years) for patients with PD subtype tumors, 2.16 years (range, 0.35-9.90) for patients with D subtype tumors, and 3.26 years (range, 0.57-15.90 years) for patients with GNBn tumors. CONCLUSIONS: This study confirmed the prognostic significance of the International Classification, substantiated age-linked prognostic effects of the morphologic indicators for patients with the tumors in the NB category, and supported the concept of an age-appropriate framework of maturation for patients with the tumors in the FH group.

Histopathology defines prognostic subsets of ganglioneuroblastoma, nodular.

BACKGROUND: Ganglioneuroblastoma, nodular (GNBn) is a rare subtype of the family of neuroblastic tumors (neuroblastoma, ganglioneuroblastoma, and ganglioneuroma) that are classified in the unfavorable histology group according to the International Neuroblastoma Pathology Classification (Shimada system). Tumors of this subtype have been considered to represent a prototypic example of biologically and clinically nonaggressive (Schwannian stroma-rich and stroma-dominant) components combined with biologically and clinically aggressive nodular (Schwannian stroma-poor) components. However, detailed histopathologic analysis as well as thorough prognostic evaluation of patients with this subtype has not been reported. METHODS: Pathology slides and reports from a total of 70 GNBn patients from the Children's Cancer Group (CCG)-3881 and CCG-3891 studies were reviewed. Sixty-eight tumors were classified in the favorable subset (FS) or the unfavorable subset (US) based on the evaluation of nodular components by applying the same histopathologic criteria (patient age, grade of neuroblastic differentiation, mitosis-karyorrhexis index) that are used for neuroblastomas in the International Neuroblastoma Pathology Classification. Patient prognosis as well as clinical and biologic characteristics within the subsets were analyzed, and the results were compared with those from 654 non-GNBn patients who were enrolled in the same CCG studies during the same period. RESULTS: Patients with GNBn tumors, usually diagnosed at age > 1 year, had a significantly lower overall 5-year event free survival (EFS) rate than patients with non-GNBn subtypes (44.7% EFS vs. 65.0% EFS; P = 0. 0073). A significant difference in the outcome of the patients between the FS (22 patients; 86.1% EFS; 95.0% survival rate) and the US (46 patients; 29.0% EFS; 40.7% survival rate) of the GNBn subtype (P < 0.0005) was shown. When the cohort of patients with GNBn tumors was subdivided into FS and US, the outcomes were similar to those of patients with tumors of favorable histology (397 patients; 90.5% EFS; 97.6% survival rate) and with tumors of unfavorable histology (257 patients; 27.0% EFS; 35.7% survival rate) of the non-GNBn type. The patients with US tumors frequently (63.0%) presented with distant metastasis. CONCLUSIONS: The current study demonstrates that the nodular components in GNBn tumors are not always aggressive. The prognosis of these patients can be determined by the analysis of age-linked histopathologic features.

Terminology and morphologic criteria of neuroblastic tumors: recommendations by the International Neuroblastoma Pathology Committee.

BACKGROUND: As part of the international cooperative effort to develop a complete set of International Neuroblastoma Risk Groups, the International Neuroblastoma Pathology Committee (INPC) initiated activities in 1994 to devise a morphologic classification of neuroblastic tumors (NTs; neuroblastoma, ganglioneuroblastoma, and ganglioneuroma). METHODS: Six member pathologists (H.S., I.M.A., L.P.D., J.H., V.V.J., and B.R.) discussed and defined morphologically based classifications (Shimada classification; risk group and modified risk group proposed by Joshi et al.) on the basis of a review of 227 cases, using various pathologic characteristics of the NTs. The classification-grading system was evaluated for prognostic significance and biologic relevance. RESULTS: The INPC has adopted a prognostic system modeled on one proposed by Shimada et al. It is an age-linked classification dependent on the differentiation grade of the neuroblasts, their cellular turnover index, and the presence or absence of Schwannian stromal development. Based on morphologic criteria defined in this article, NTs were classified into four categories and their subtypes: 1) neuroblastoma (Schwannian stroma-poor), undifferentiated, poorly differentiated, and differentiating; 2) ganglioneuroblastoma, intermixed (Schwannian stroma-rich); 3) ganglioneuroma (Schwannian stroma-dominant), maturing and mature; and 4) ganglioneuroblastoma, nodular (composite Schwannian stroma-richlstroma-dominant and stroma-poor). Specific features, such as the mitosis-karyorrhexis index, the mitotic rate, and calcification, were also included to allow the prognostic significance of the classification to be tested. Recommendations are made regarding the surgical materials to use for an optimal pathobiologic assessment and the practical handling of samples. CONCLUSIONS: The current article covers the essentials and important points regarding the histopathologic evaluation of NTs. Using the morphologic criteria described herein, the INPC is proposing the International Neuroblastoma Pathology Classification. It is reported in a companion article in this issue (Cancer 1999;86:363-71).

The International Neuroblastoma Pathology Classification (the Shimada system).

BACKGROUND: The International Neuroblastoma Pathology Committee, which is comprised of six member pathologists, was convened with the objective of proposing a prognostically significant and biologically relevant classification based on morphologic features of neuroblastic tumors (NTs) (i.e., neuroblastoma, ganglioneuroblastoma, and ganglioneuroma). METHODS: A total of 227 cases were reviewed. Consensus diagnoses from morphologic features (criteria described separately) based on five of six or six of six agreements by the reviewer pathologists were used for prognostic analysis. Prognostic effects of morphology, both individual and in combination, taken in conjunction with age (Shimada classification, histologic grade, and risk group), were analyzed. RESULTS: Approximately 99% of cases (224 of 227) had consensus diagnoses for categorization: neuroblastoma (Schwannian stroma-poor), 190 cases; ganglioneuroblastoma, intermixed (Schwannian stroma-rich), 5 cases; ganglioneuroma (Schwannian stroma-dominant) maturing, 1 case; ganglioneuroblastoma, nodular (composite Schwannian stroma-rich/stroma-dominant and stroma-poor), 19 cases; and NT-unclassifiable, 9 cases. For the NTs, subtype (93% consensus: undifferentiated, 6 cases; poorly differentiated, 155 cases; and differentiated, 15 cases), mitosis-karyorrhexis index (90% consensus: low, 94 cases; intermediate, 40 cases; and high, 37 cases), mitotic rate (75% consensus: low, 89 cases; high, 50 cases; and not determined, 4 cases), and calcification (100% consensus: yes, 110 cases and no, 80 cases) were recorded. Statistical analysis demonstrated that the Shimada classification system (90% consensus; 3-year event free survival: 85% for the group with favorable histology and 41% for the group with unfavorable histology; P = 0.31 x 10(-9)) had a significantly stronger prognostic effect than individual features and other combinations. CONCLUSIONS: The International Neuroblastoma Pathology Classification, a system based on a framework of the Shimada classification with minor modifications, is proposed for international use in assessing NTs.

Conventional versus modified morphologic criteria for ganglioneuroblastoma. A review of cases from the Pediatric Oncology Group.

BACKGROUND: Conventional criteria for ganglioneuroblastoma (GNB) do not require the presence of ganglioneuromatous component for pathologic diagnosis. This leads to inclusion of a mixed variety of neuroblastic tumors in the category of GNB. Therefore, GNB diagnosed by conventional criteria includes tumors showing more than 5% ganglion cells but no predominant ganglioneuromatous component, as well as tumors containing predominant ganglioneuromatous component. By previously described modified criteria, the former would be considered differentiating neuroblastoma (NB), and only the latter would be considered GNB. Data on Pediatric Oncology Group cases were analyzed to compare the prognostic subgroups of GNB diagnosed by conventional and modified criteria. The two prognostic subgroups (low risk and high risk) were defined on the basis of previously described prognostic differences between histologic grades of differentiating NBs and subtypes of GNB. METHODS: Pathologic data from cases of neuroblastic tumors registered on Pediatric Oncology Group NB protocols 8104 and 8441 were reviewed. The GNBs diagnosed by conventional and modified criteria were divided into low-risk and high-risk histology subgroups as follows: (1) GNB by conventional criteria: low-risk group, differentiating NB of histologic grades 1 and 2 and GNB of intermixed and borderline subtypes; high-risk group, differentiating NB of histologic grade 3 and GNB of nodular subtype; (2) GNB by modified criteria: low-risk group, GNB of intermixed and borderline subtypes; high-risk group, GNB of nodular subtype. RESULTS: The low- and high-risk subgroups of GNBs diagnosed by conventional (69 cases) and modified (36 cases) criteria showed statistically significant differences in survival (P = .03 and .01, respectively). However, from the histologic point of view, GNBs diagnosed by modified criteria form a more uniform morphologic group, which can be divided into low- and high-risk subgroups by a single set of morphologic criteria. In contrast, GNBs diagnosed by conventional criteria form a heterogeneous group, which requires two sets of criteria (ie, histologic grade and subtypes of GNB) for its classification into low- and high-risk subgroups. CONCLUSIONS: The modified criteria for GNB define a morphologically uniform group of neuroblastic tumors to which a single set of prognostic criteria can be applied. It is recommended that the term GNB should be used both clinically and pathologically to designate a distinctive subgroup of neuroblastic tumors, in contrast to the current use, which designates both NB and GNB.

Comparison of ultrastructural features among neuroblastic tumors: maturation from neuroblastoma to ganglioneuroma.

Neuroblastic tumors have the unique ability to differentiate and mature. This family of tumors is composed of the neuroblastoma, ganglioneuroblastoma, and ganglioneuroma. These tumors are derived from primordial neural crest cells that form the sympathetic nervous system. The purpose of this study was to characterize the ultrastructural features of neuroblastic tumors in a pediatric population. Forty-five neuroblastic tumors (15 neuroblastomas, 15 ganglioneuroblastomas, and 15 ganglioneuromas) were examined using standard transmission electron microscopic techniques. Undifferentiated neuroblastomas were composed of primitive cells with rare neurite-like processes containing clear secretory vesicles and no Schwann cell differentiation. Poorly differentiated and differentiating neuroblastomas showed more frequent neuritic processes with infrequent dense core granules and infrequent immature Schwann-like cells. Ganglioneuroblastomas possessed an admixture of cell types, including immature ganglion cells without associated satellite cells, intermediate cells, and differentiating neuroblasts. The neuropil contained immature Schwann cells encasing haphazardly arranged neuritic processes. Ganglioneuromas were composed of mature ganglion cells with occasional binucleation. The neuropil contained mature Schwann cells with well-organized neuritic processes and abundant collagen deposition. Differentiation or maturation of tumor cells, neuritic processes, and Schwann cells may thus be discerned ultrastructurally in primary neuroblastic tumors in pediatric patients.

Tumors of the neuroblastoma group.

The basic histologic changes associated with the maturational sequences of neuroblastoma tumors are reviewed. The author describes a histopathologic classification system developed for distinguishing favorable and unfavorable prognoses, based on the combination of tumor morphology and patient's age at diagnosis. Also discussed are the results of recent analyses of the biologically significant relationship between histologic findings and molecular markers, such as amplification of the N-myc oncogene and expression of the nerve growth factor receptor gene. Clinical trials involving neuroblastoma tumors are briefly reviewed.