Nervous System
Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard in Toxicologic Pathology, 2018
These are poorly demarcated tumors, usually of modest size, confined to one major area of the CNS (low grade) or extensive, multicentric, or diffuse lesions with no discernible boundaries spreading over two or more major areas of the CNS (high grade) (Figure 22.11a). Large tumors may, but seldom do, cause clinical signs before the end of a 104-week rat study. They show variable cellularity and may infiltrate the meninges and ependyma. The neoplastic cells show uniform or anaplastic features, including round or fusiform nuclei, a variable amount of eosinophilic cytoplasm, and indistinct cell borders. In larger tumors, there may also be foci of hemorrhage and necrosis, with palisading of neoplastic astrocytes around necrotic foci. Neoplastic cells appearing as perineuronal satellitosis and perivascular cuffing may be present at the periphery of the neoplasm. Reactive astrocytes (gemistocytes positive for GFAP) may be present.
Neoplasms of the Abdomen and Gastrointestinal Tract
John F. Pohl, Christopher Jolley, Daniel Gelfond in Pediatric Gastroenterology, 2014
The treatment of Wilms tumor is multimodality and has been well-defined through the National Wilms Tumor Study (and its successor the Children’s Oncology Group) in North America and the International Society of Paediatric Oncology in Europe. Overall prognosis for children with Wilms tumor is excellent when treated with multimodality therapy. The most important determinants of prognosis are diffuse anaplastic histology and tumor stage. Anaplasia is a marker for resistance to chemotherapy and is associated with worse outcomes for all stages. Loss of heterozygosity at 1p and 16q has recently been identified as a marker for increased risk in children with tumors without anaplasia. The question of whether children whose tumors have loss of heterozygosity benefit from intensification of therapy is currently being investigated.
An Immunohistological Approach to the Differential Diagnosis of Childhood Brain Tumors
John T. Kemshead in Pediatric Tumors: Immunological and Molecular Markers, 2020
Cell surface differentiation antigens which are related to the cell surface and are relevant to brain tumor diagnosis are defined by antibodies UJ13A, UJ127.11, 2D1, B1, and UCHT1 (Table 4). Antibody UJ13A is a most useful reagent; immunohistologically, it will identify all tumors of neuroectodermal origin, both central and peripheral. The single exception is melanoma which does not express this antigen. Its principal role in our laboratories is in the diagnosis of anaplastic or small round cell tumors in which there is doubt as to the tissue of origin. This antibody has already been used clinically in the removal of neuroblastoma cells from bone marrow prior to autologous transplantation24 and in radioimmunolocalization of neuroblastoma25 and brain tumors.26
Dedifferentiated transformation in metastatic liposarcoma of orbit and brain
Published in Orbit, 2020
Sung Eun Kim, Ji Hyun Kim, Suk-Woo Yang
A wide excision of the involved dura, frontal sinus and frontal bone was additionally performed which also showed findings consistent with a poorly differentiated metastatic liposarcoma. The histologic findings indicated that the tissue was the least differentiated and anaplastic. The tumor had highest cellularity and more round cell components and myxoid stroma was negligible (Figure 3). The patient received adjuvant radiation therapy of the left frontal and orbit at 66 Gy for 30 fractions, followed by systemic etoposide, carboplatin, and ifosfamide chemotherapy. The tumor responded well to the treatment. The tumor response was further examined by medical and radiation oncologists using serial imaging studies including chest CT, abdominal CT, bone scan, orbit MRI, brain MRI and right knee MRI. No residual tumor was found. His vision has remained normal throughout the treatment with no ophthalmologic complications and no recurrence has been detected for 3 years of follow-up.
A Multicenter Study of Clinicopathology and Immunohistochemical Distinction between Adult and Pediatric Large B-Cell Lymphoma
Published in Fetal and Pediatric Pathology, 2023
Thu Dang Anh Phan, Tu Thanh Duong, Diem Thi Nhu Pham, Minh Hoang Dang, Thien Thanh Ly, Hanh Thi Tuyet Ngo, Dat Quoc Ngo, Nguyen Dinh The Trinh, Uyen Le Ly, Tu Anh Thai, Ha Thi Ngoc Hua, Thao Thi Phuong Doan
According to the WHO classification, DLBCL is the diffuse proliferation of large mature B-cells with a nuclear size that varies from medium to large, equal to or exceeding normal histiocyte nuclei [6]. DLBCL demonstrates a broad cytologic spectrum that includes a group of tumors with heterogeneity of morphology, immunophenotype, and clinical features rather than a single entity. Three typical cell patterns (centroblastic, immunoblastic, and anaplastic) have been described. In adults, DLBCL has been classified into biologically and clinically relevant subtypes: germinal center B-cells (GCBs) and non-GCB tumors, which have considerable differences in genetic markers expression, activation pathways, and immunophenotypic features. DLBCLs with gene expression GCB show a better prognosis than non-GCB DLBCLs [10, 11]. Classifying DLBCL as GCB or non-GCB is most likely to make a biological difference, which may lead to treatment decisions. While information on the pathogenesis and biology of adult DLBCL cases is more plentiful, data on DLBCL in children are limited.
Role of gamma knife radiosurgery for recurrent or residual World Health Organization grade II and III intracranial meningiomas
Published in British Journal of Neurosurgery, 2020
Moinay Kim, Young Hyun Cho, Jeong Hoon Kim, Chang Jin Kim, Sung Woo Roh, Do Hoon Kwon
The risk of malignant transformation with radiosurgery has been a matter of concern.39–41 The mechanism of an increase in tumour grade with aggressive behaviour is yet unclear. Few available clinical studies have reported an incidence rate of this phenomenon between 18–27%.22,30,42 Malignant transformation may result from an accumulation of genetic changes such as loss of CDKN2AB expression or TERT promoter mutations.43 However, tumour grading at time of relapse is uncertain; whether the tumour is still atypical, or transformed to anaplastic. This may explain the phenomenon of some meningiomas with rapid growth at a distance from the site of resection or SRS.44 There were 3 cases of malignant transformation in our study and it was not significantly associated with tumour recurrence or survival (Figure 2). It is difficult to distinguish whether the malignant process was accelerated by radiosurgery, or whether the resected tumours were in fact initially high-grade tumours. Nevertheless, the possibility of malignant transformation must be considered in meningiomas with successive recurrences prior to radiosurgery. In our study, the earliest detection of tumour recurrence after GKRS was 5 months (median 29.5 months), which was a case of transformation from atypical to anaplastic meningioma. Hence, early tumour recurrence could be a clue of malignant transformation as well.
Related Knowledge Centers
- Cell Division
- Morphology
- Endothelium
- Cellular Differentiation
- Neoplasm
- Nucleolus
- Cell
- Pleomorphism
- Nc Ratio
- Malignant Transformation