Pleomorphic Xanthoastrocytoma with Oligodendroglioma-Like Areas with Negative 1p19q Co-Deletion

The most common mixed glioma encountered in routine surgical practice is oligoastrocytoma (OA); however, its is currently considered a vanishing entity. The 2016 classification of the World Health Organization (WHO) discourages the diagnosis of tumors as mixed glioma. The recommendations are that diffuse gliomas, including those withmixed or ambiguous histological features, should be subjected tomolecular testing. Dual-genotype OAs are not yet a distinct entity or variant in the classification. We report a case ofmixed glioma: a pleomorphic xanthoastrocytoma (PXA)mixed with an oligodendroglioma. The immunohistochemistry (IHC) pattern of isocitrate dehydrogenase 1 (IDH1) negativity with retained nuclear expression of the alpha-thalassemia x-linked intellectual disability syndrome (ATRX) protein, and 1p19q co-deletion negativity in both the components enabled its identification as a mixed glioma rather than a collision tumor. To the best of our knowledge, the case herein presented is the fourth case of PXA with oligodendroglioma. Out of the other three reported cases, only one was of a collision tumor with a dual genotype, and the other two showed similar molecular signatures in both components. The present article discusses the histological, immunohistochemical and molecular features of the aforementioned case.

Nodular lymphocyte predominant Hodgkin lymphoma and diphenylhydantoin: Report of a case and review of the literature.

A variety of lymphoma types have been reported in patients being treated with anticonvulsant therapy. Non-Hodgkin lymphomas have been reported twice as frequently as Hodgkin lymphomas. Association of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) with dilantin therapy is extremely uncommon. We report a case of Hodgkin lymphoma in a 25-year-old male patient who had been treated with diphenylhydantoin sodium for generalized tonic clonic seizures for 15 years. Patient presented with left cervical and axillary lymphadenopathy persisting for more than 2 years after cessation of treatment with diphenylhydantoin. Computerized tomography scan of thorax, abdomen and pelvis revealed no signifi cant lymphadenopathy or any organomegaly. Diagnosis of NLPHL was made on excision biopsy of the cervical lymph node. Although the association between diphenylhydantoin therapy and the development of immunosuppression and lymphoma is well-documented, the role of the drug in the etiology of these disorders is still controversial.