OBJECTIVETo discuss the clinicopathologic features of rhabdoid glioblastoma of the brain and its differential diagnoses.

METHODSA 10-year-old and a 45-year-old female both presented with gradually worsening headache, limbs twitch and blurred vision. MRI scan revealed a contrast enhancing tumor in the right temporal lobe and left cerebellum respectively. Both patients underwent tumor resection, followed by postoperative radiotherapy and chemotherapy.

RESULTSMicroscopic examination of both tumors showed rhabdoid tumor cells with an eccentric nuclei and eosinophilic cytoplasms. Both tumors had areas of classic glioblastoma with microvascular proliferation and necrosis. Immunohistochemical staining showed the rhabdoid tumor cells were positive for vimentin diffusely and GFAP, EMA, CK focally. Integrase interactor (INI-1) was expressed in most tumor cells, but IDH1 R132H was not detected in both tumors. Fluorescence in situ hybridization revealed 1p/19q co-deletion in one case. One patient was alive without tumor recurrence after 16 months follow-up, the other patient died of intraspinal tumor dissemination 9 months after surgery.

CONCLUSIONSRhabdoid glioblastoma is a rare glial cell tumor with specific rhabdoid tumor cells, a highly aggressive clinical course and poor prognosis. Combining histological features, a panel of selected immunostains including vimentin, GFAP, CK, EMA, SMA and INI-1 is helpful in making an accurate diagnosis for those diagnostically challenging cases with rhabdoid features in central nervous system.

Biomarkers, Tumor ; metabolism ; Brain Neoplasms ; pathology ; Child ; Diagnosis, Differential ; Female ; Glioblastoma ; pathology ; Humans ; In Situ Hybridization, Fluorescence ; Magnetic Resonance Imaging ; Middle Aged ; Necrosis ; Neoplasm Recurrence, Local ; Rhabdoid Tumor ; pathology ; Temporal Lobe ; pathology

OBJECTIVETo study the clinicopathologic characteristics of extrarenal malignant rhabdoid tumor (E-MRT) with emphasis on diagnosis and differential diagnosis.

METHODSThe clinical and pathologic data of 8 E-MRT cases were reviewed. The outcome was analyzed.

RESULTSThere were four males and four females. The age at presentation ranged from 3 days to 8 years (mean, 2.6 years; median, 3 years). The tumors were located in the extremities (n = 1), head and neck (n = 2), trunk (n = 2), cervical cord (n = 1), liver (n = 1) and retroperitoneum (n = 1). Histologically, the tumors were composed of a diffuse proliferation of rounded or polygonal cells with eccentric nuclei, prominent nucleoli, and glassy eosinophilic cytoplasm containing hyaline-like inclusion bodies, arranged in sheets and nests. Cellular atypia was easily observed and mitotic activity was high. Necrotic and hemorrhagic areas were abundant. On immunohistochemistry, the tumor cells expressed vimentin and epithelial marker such as EMA, AE1/AE3, and CAM5.2. The absence of INI1 protein expression was a distinctive feature. Follow-up of all eight cases revealed five deaths in one year and the other three were disease-free at last follow-up of one month, three months and seven months.

CONCLUSIONSE-MRT is a rare and highly aggressive tumor of infancy and childhood. Recurrence and distant metastasis was common and the 5-year survival rate is low. Increased awareness of the clinocopathologic features and immunophenotypes of E-MRT is helpful for correct diagnosis and effective treatment.

Child ; Child, Preschool ; Diagnosis, Differential ; Extremities ; Female ; Head and Neck Neoplasms ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Infant ; Infant, Newborn ; Male ; Neoplasm Recurrence, Local ; Retroperitoneal Neoplasms ; metabolism ; pathology ; Rhabdoid Tumor ; metabolism ; pathology ; Treatment Outcome ; Vimentin ; metabolism

OBJECTIVETo study the immunophenotype and molecular genetics of epithelioid sarcoma (ES), INI1 expression and its role in differential diagnosis.

METHODSTwenty cases of ES were retrieved from the archival files and selected for immunohistochemical study, DNA sequencing and fluorescence in-situ hybridization. The clinical and pathologic features were also reviewed.

RESULTSThe age of patients ranged from 16 to 75 years (mean = 40.2 years). The median age of patients in classic ES and proximal-type was 37.9 years and 42.0 years, respectively. The male-to-female ratio was 1.2: 1.0. Classic ES mostly occurred in the extremities while proximal-type ES often affected the perineum and external genitalia and trunk. Histologically, granuloma-like structures, consisting of aggregates of epithelioid and spindly tumor cells with central necrosis, were observed in classic ES. The epithelioid tumor cells contained abundant eosinophilic cytoplasm, merged with spindly cells at the periphery and admixed with collagen fibers. In proximal-type ES, the tumor cells showed prominent epithelioid and/or rhabdoid features, had marked cytologic atypia and grew in multinodular or diffuse patterns. In 2 cases of proximal-type ES studied, the "rhabdoid" tumor cells demonstrated a diffuse sheet-like growth pattern, mimicking malignant rhabdoid tumor. Immunohistochemical study showed that vimentin was positive in all cases. Pan-cytokeratin, CK8, CK7, epithelial membrane antigen and CD34 were expressed in 16, 15, 1, 18 and 13 cases, respectively. The staining for S-100 protein was focal and weak in 5 cases. None of the cases studied expressed CD31 and HMB45. Loss of INI1 was demonstrated in 10 of the 13 classic ES cases and 5 of the 7 proximal-type ES cases. The mutation of INI1 gene was detected in 1 of the 6 cases. Deletion of INI1 gene including heterozygous deletion, homozygous deletion and haploid was observed in 8 of the 11 cases.

CONCLUSIONSOwing to the histologic heterogeneity, pitfalls in diagnosis of ES sometimes are encountered. INI1 is lost in most cases of ES. Immunohistochemical study, including staining for INI1, provides useful clues in pathologic diagnosis. Instead of INI1 mutation, inactivation of INI1 gene related deletion is not uncommon.

Adolescent ; Adult ; Aged ; Antigens, CD34 ; metabolism ; Chromosomal Proteins, Non-Histone ; genetics ; DNA-Binding Proteins ; genetics ; Female ; Gene Deletion ; Humans ; Immunophenotyping ; In Situ Hybridization, Fluorescence ; Keratins ; metabolism ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Mutation ; Rhabdoid Tumor ; genetics ; SMARCB1 Protein ; Sarcoma ; genetics ; Transcription Factors ; genetics ; Young Adult

Chromosomal Proteins, Non-Histone ; metabolism ; DNA-Binding Proteins ; metabolism ; Diagnosis, Differential ; Follow-Up Studies ; Humans ; Infant ; Infant, Newborn ; Keratins ; metabolism ; Male ; Mucin-1 ; metabolism ; Phosphopyruvate Hydratase ; metabolism ; Rhabdoid Tumor ; metabolism ; pathology ; surgery ; Rhabdomyosarcoma ; metabolism ; pathology ; S100 Proteins ; metabolism ; SMARCB1 Protein ; Sarcoma ; metabolism ; pathology ; Sarcoma, Clear Cell ; metabolism ; pathology ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Transcription Factors ; metabolism ; Vimentin ; metabolism

Actins ; metabolism ; Calcium-Binding Proteins ; metabolism ; Calmodulin-Binding Proteins ; metabolism ; Desmin ; metabolism ; Diagnosis, Differential ; Female ; Humans ; Hysterectomy ; Leiomyoma, Epithelioid ; metabolism ; pathology ; Leiomyomatosis ; metabolism ; pathology ; surgery ; Leiomyosarcoma ; pathology ; Microfilament Proteins ; metabolism ; Middle Aged ; Receptors, Estrogen ; metabolism ; Receptors, Progesterone ; metabolism ; Rhabdoid Tumor ; metabolism ; pathology ; surgery ; Sarcoma, Endometrial Stromal ; metabolism ; pathology ; Uterine Neoplasms ; metabolism ; pathology ; surgery ; Vascular Neoplasms ; metabolism ; pathology ; surgery ; Veins ; pathology ; Vimentin ; metabolism

OBJECTIVETo study the clinicopathologic features, immunohistochemical findings, diagnosis and differential diagnosis of atypical teratoid/rhabdoid tumors (AT/RT) of central nervous system in childhood.

METHODSThe clinicopathologic data, morphologic features and immunophenotypes were reviewed in 6 cases of AT/RT. EnVision method was applied. Antibodies include cytokeratin (CK), epithelial membrane antigen (EMA), vimentin, smooth muscle actin (SMA), muscle specific actin (MSA), glial fibrinary acid protein (GFAP), desmin, placental alkaline phosphatase (PLAP) and INI1.

RESULTSFive of the six cases of AT/RT occurred in infancy and early childhood. Histologically, the predominant component was rhabdoid cells. Cytoplasmic inclusions were present in all cases. Primitive neuroectodermal tumor (PNET) component was also identified in 5 of the 6 cases studied. Immunohistochemically, the tumor cells were positive for cytokeratin, epithelial membrane antigen and vimentin. The staining for INI1, desmin and PLAP was negative. Smooth muscle actin was expressed in 2 cases and glial fibrillary acidic protein in 5 cases. The proliferative index as demonstrated by Ki-67 staining was high.

CONCLUSIONSAT/RT is not a particularly uncommon malignancy in childhood. The histologic hallmark is the presence of rhabdoid cells with cytoplasmic inclusions. The tumor cells are positive for cytokeratin, epithelial membrane antigen and vimentin, and negative for INI1. Differential diagnosis includes PNET, medulloblastoma and medullomyoblastoma.

Brain Neoplasms ; metabolism ; pathology ; surgery ; Child, Preschool ; Diagnosis, Differential ; Female ; Humans ; Infant ; Keratins ; metabolism ; Male ; Medulloblastoma ; metabolism ; pathology ; Mucin-1 ; metabolism ; Neuroectodermal Tumors, Primitive ; metabolism ; pathology ; Rhabdoid Tumor ; metabolism ; pathology ; surgery ; Teratoma ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Child, Preschool ; Dactinomycin ; administration & dosage ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Infant ; Kidney Neoplasms ; drug therapy ; metabolism ; pathology ; surgery ; Male ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rhabdoid Tumor ; drug therapy ; metabolism ; pathology ; surgery ; Rhabdomyosarcoma ; pathology ; Sarcoma, Clear Cell ; metabolism ; pathology ; Synaptophysin ; metabolism ; Vimentin ; metabolism ; Vincristine ; administration & dosage ; Wilms Tumor ; pathology

Astrocytoma ; genetics ; metabolism ; pathology ; Brain Neoplasms ; classification ; genetics ; metabolism ; pathology ; Child ; Child, Preschool ; Chromosomal Proteins, Non-Histone ; genetics ; metabolism ; Chromosome Deletion ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Ependymoma ; genetics ; metabolism ; pathology ; Hedgehog Proteins ; genetics ; metabolism ; Humans ; Medulloblastoma ; classification ; genetics ; metabolism ; pathology ; Proto-Oncogene Proteins B-raf ; genetics ; metabolism ; Rhabdoid Tumor ; genetics ; metabolism ; pathology ; SMARCB1 Protein ; Signal Transduction ; Transcription Factors ; genetics ; metabolism ; Wnt Proteins ; metabolism ; beta Catenin ; genetics ; metabolism

Adult ; Diagnosis, Differential ; Female ; Humans ; Keratins ; metabolism ; Lymphatic Metastasis ; Mucin-1 ; metabolism ; Rectal Neoplasms ; metabolism ; pathology ; surgery ; Rhabdoid Tumor ; metabolism ; pathology ; surgery ; Sarcoma ; metabolism ; pathology ; Synaptophysin ; metabolism ; Vimentin ; metabolism ; Young Adult

Diagnosis, Differential ; Hemangiopericytoma ; metabolism ; pathology ; Hemangiosarcoma ; metabolism ; pathology ; Histiocytoma, Malignant Fibrous ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Leiomyosarcoma ; metabolism ; pathology ; Nerve Sheath Neoplasms ; metabolism ; pathology ; Neuroectodermal Tumors, Primitive ; metabolism ; pathology ; Rhabdoid Tumor ; metabolism ; pathology ; Rhabdomyosarcoma ; metabolism ; pathology ; Soft Tissue Neoplasms ; metabolism ; pathology ; Urinary Bladder ; metabolism ; pathology