ABSTRACT
<p><b>OBJECTIVE</b>To study the clinicopathologic features, immunophenotype and histogenesis of dysembryoplastic neuroepithelial tumor (DNT).</p><p><b>METHODS</b>Fourteen cases of DNT were retrieved from the archival files of the Department. The histopathologic features and immunohistochemical findings were retrospectively studied. The long-term follow-up data were analyzed.</p><p><b>RESULTS</b>Eleven of the 14 cases studied were located in the temporal lobe. Histologically, the tumor consisted of a heterogeneous admixture of neuronal and glial cells (including 1 simple form case, 8 complex form cases and 5 non-specific form cases). The specific glioneuronal element was seen in 9 cases. Variable degrees of cortical dysplasia (CD) were found in 10 out of the 11 cases which had sufficient tissue samples for thorough histologic examination. The morphologic appearance of CD included the presence of heterotopic neurons in molecular layer and/or white matter (7 cases), persistent subpial granular cell layer (4 cases), dyslamination (10 cases) and cellular abnormalities. Immunohistochemically, the oligodendroglial-like cells expressed Olig2. Some of which were positive for nestin, MAP-2, neurofilament and glial fibrillary acidic protein, but negative for NeuN. Long-term follow up revealed that 12 patients had class I postoperative seizure and 2 patients had class II seizure. No tumor recurrence was detected.</p><p><b>CONCLUSIONS</b>DNT is frequently associated with CD. The morphologic diagnosis can be confirmed by immunohistochemical study using a panel of antibodies.</p>
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Male , Young Adult , Anticonvulsants , Therapeutic Uses , Basic Helix-Loop-Helix Transcription Factors , Metabolism , Brain Neoplasms , Metabolism , Pathology , General Surgery , Epilepsy , Drug Therapy , Follow-Up Studies , Intermediate Filament Proteins , Metabolism , Malformations of Cortical Development , Pathology , Microtubule-Associated Proteins , Metabolism , Neoplasms, Neuroepithelial , Metabolism , Pathology , General Surgery , Nerve Tissue Proteins , Metabolism , Nestin , Oligodendrocyte Transcription Factor 2 , Oligodendroglia , Pathology , Retrospective StudiesABSTRACT
<p><b>OBJECTIVE</b>To study the loss of heterozygosity (LOH) at chromosomes 1p or 19q in oligodendroglial tumors.</p><p><b>METHODS</b>Twenty-eight cases of oligodendroglial tumors were enrolled into the study. Real-time quantitative polymerase chain reaction-based microsatellite analysis was performed on paraffin-embedded tumor tissues in order to study the status of chromosomes 1p and 19q.</p><p><b>RESULTS</b>Among the 28 cases of oligodendroglial tumors, 24 cases (85.7%) showed 1p LOH, while 18 cases (64.3%) showed 19q LOH and 17 cases (60.7%) showed LOH of both 1p and 19q. LOH at 1p or 19q was present in 25 (89.3%) of the 28 cases.</p><p><b>CONCLUSIONS</b>Real-time quantitative polymerase chain reaction-based microsatellite analysis is a rapid and specific way in detecting LOH in paraffin-embedded tumor tissues. LOH at 1p or 19q is present in majority of the oligodendroglial tumors studied.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Brain Neoplasms , Genetics , Chromosomes, Human, Pair 1 , Chromosomes, Human, Pair 19 , Loss of Heterozygosity , Microsatellite Repeats , Oligodendroglioma , Genetics , Polymerase Chain Reaction , MethodsABSTRACT
<p><b>OBJECTIVE</b>To study the immunohistochemical expression of OCT4, CD117 and CD30 in germ cell tumors and to assess their diagnostic value.</p><p><b>METHODS</b>Immunohistochemical study for OCT4 was performed on formalin-fixed, paraffin-embedded tissues of 63 cases of germ cell tumors, including seminoma (21), dysgerminoma (7), germinoma (8), embryonal carcinoma (8), yolk sac tumor (6), mature teratoma (10) and immature teratoma (3), as well as 25 cases of non-germ cell tumors, including granulosa cell tumor (8), clear cell adenocarcinoma (4), Leydig's cell tumor (5), diffuse large B-cell lymphoma (4) and malignant melanoma (4). Besides, the expression of CD117 and CD30 in all germ cell tumors was studied.</p><p><b>RESULTS</b>All cases of seminoma and germinoma, 6/7 cases of dysgerminoma and 7/8 cases of embryonal carcinoma were positive for OCT4, with strong nuclear staining. All other germ cell tumors and non-germ cell tumors were negative for OCT4, except for 1 case of yolk sac tumor and 1 case of clear cell adenocarcinoma which showed weak staining. Positive membranous expression of CD117 was demonstrated in 19/21(90.5%) seminoma, 5/7 dysgerminoma and 7/8 germinoma. Focal weak membranous staining was also noted in 1 case of yolk sac tumor. The melanocytes in teratoma were also positive for CD117. All cases of embryonal carcinoma were negative. On the other hand, positive membranous expression of CD30 were demonstrated in 6/8 embryonal carcinoma. One case of germinoma and 1 case of yolk sac tumor showed weak cytoplasmic positivity. All cases of seminoma and dysgerminoma, 7/8 germinoma and all cases of teratoma were negative for CD30.</p><p><b>CONCLUSIONS</b>OCT4 is a sensitive and relatively specific marker for diagnosing seminoma, dysgerminoma, germinoma and embryonal carcinoma. CD117 and CD30 immunostains, when used in combination, represent valuable tools for distinguishing embryonal carcinoma and seminoma, dysgerminoma, germinoma.</p>