Background and purpose:In the primary cutaneous CD30 positive lymphoproliferative disorders, despite the common reports about the primary cutaneous anaplastic large cell lymphoma and lymphomatoid papulosis, such reports about the bordline disease-lymphomatoid papulosis (type C) were rare. This article was to introduce and discuss its clinical manifestations and morphological and immunophenotypic features. Methods:Based on the related literature, we reviewed the clinical,pathological and immunohistochemical features from one case presented in Huashan Hospital. Results:The patient, male, was 56 years old with systemic red papuloid skin lesions accompanied with pruritus, which were sporadic, chronic, recurrent and self-healing. The duration of the disease persisted more than 26 years. Recently, the multiple papuloid lesions developed to be agrias, ulcerations and black eschars. Histopathologically, besides the ulcerated epiderm exfoliation, there were medium and large atypical lymphocytes in? trating in dermis layer. These cells showed postive for CD30,TIA-1 and CD3, and negative for ALK and CD20. Conclusions:When diagnosing LyP (type C),a rare disease, we should differentiate it from the primary cutaneous anaplastic large cell lymphoma (C-ALCL) and systemic anaplastic large cell lymphoma involving the skin, and also combine the clinical and histopathological characteristics and immunophenotype to identify its defi nition and nature.

Purpose To investigate the clinical,imaging,pathological features,differential diagnosis and prognosis of em-bryonic dysplastic neuroepithelial tumor(DNT).Methods The clinical data of 33 DNT patients were collected.Immunohis-tochemical results of Olig2,NeuN,Syn,GFAP,IDH1,CD34,BRAF V600E,H3K27M and Ki67 were examined by EnVision method.Histopathological morphology and immunohistochemical features were retrospectively analyzed and relevant literature was reviewed synchronously.Results A total of 28 cases were fol-lowed up,including 10 females and 18 males.The age of onset was 4～57 years,with average 24.97 years.Refractory epilepsy was a common symptom.The lesions were mainly located in the supratentorial cortex,and most of them were well-defined,lobu-lated,cystic or cystic and solid.Microscopically,DNT was mainly composed of oligodendrocytes,neurons floating in the mucous matrix,and proliferative astrocytes.Calcification was rare,and no necrosis or microvascular hyperplasia was ob-served.Immunohistochemistry showed that neurons expressed NeuN and Syn,oligodendrocytes expressed Olig2,and prolifera-tive astrocytes expressed GFAP;p53 was mostly wild-type,and the proliferation index of Ki67 was low(mostly less than 4％).Conclusion DNT is a benign tumor with mixed glial and neu-ronal structures.Precise pathological diagnosis needs to be care-fully considered with imaging characteristics,microscopic mor-phology,immunohistochemistry and molecular test results if nec-essary.Prognosis after complete surgical resection is good.

Purpose To investigate the clinical,imaging,pathological,and genetic characteristics of neuroepithelial tumors with EWSR1 translocation.Methods The clinicopatho-logical data of 6 patients with EWSR1 translocation in neuroepi-thelial tumors were collected,routine HE and immunohistochem-ical staining were performed,the information of high-throughput sequencing was summarized,and the relevant literature was re-viewed.Results The median age of the 6 patients was 11.5 years(ranging from 1.9 to 17 years),including 1 male and 5 females.The tumors located in temporal lobe,frontal lobe,pari-etal lobe,suprasellar region,or lateral ventricle.The clinical manifestations mainly started with seizures.Brain MRI showed abnormal signal focus in the cerebral hemisphere near the cortex in 4 cases,and ventricle/periventricular regions in 2 cases,with an almost clear boundary in 5 cases.Microscopically,the histo-logical changes were diverse,including low-grade gliomas/gli-oneuronal tumors in 3 cases,high-grade gliomas in 2 cases,and glioneuronal tumor with high-grade feature in 1 case.Immuno-histochemically,tumor cells expressed GFAP,S-100,Syn,and Olig2 partially.2 cases exhibited slightly positive of NeuN and 1 case exhibited little dot-like staining of EMA.Next generation sequencing revealed EWSR1 rearrangement in all 6 cases,with chaperone genes including PATZ1 in 5 cases,and PLAGL1 in 1 case.3 cases were treated with chemotherapy after surgery,and no recurrence or progression was found during follow-up.Con-clusion The neuroepithelial tumors with the fusion of EWSR1 and non-ETS commonly occur in the cerebral hemisphere of teenagers and children.Most of the boundaries lesion are still clear,the histomorphological spectrum is diverse,and the bio-logical behavior is presented as a low to moderate malignancy,which provides the possibility for expanding the molecular classi-fication of CNS neuroepithelial tumor.