More than 90% of the world population experience the infection by Epstein-Barr virus (EBV), this virus has the potential to survive in B cells for the entire life period of infected individuals. However, if the balance between host and virus is disturbed, silent EBV infection could change to neoplasms. Socioeconomic factors affect exposure to EBV so the age of primary infection varies worldwide. In underdeveloped population infection occurs at lower age and EBV infection remains subclinical in high number of patients. Different neoplasms associated with EBV infection are EBV-positive Hodgkin lymphoma (HL), EBV-associated Burkitt lymphoma, diffuse large B-cell lymphoma, post-transplant lymphoproliferative disorders (PTLD), smooth muscle tumor and nasopharyngeal carcinoma. This review article presents detail information about pathogenesis, clinical presentation and treatment of pediatric patients with these disorders.

Background: Malignant neoplasms of the anal canal are rare accounting for approximately 4% of all colorectal malignancies.Objectives: The present study aimed to report the clinicopathological characteristics and treatment outcomes of 41 cases with malignant neoplasms of the anal canal.Patients and Methods: Between 1999 and 2012, 41 consecutive patients were diagnosed with primary malignant neoplasm of the anal canal which were treated and followed up at Namazi hospital. Only primary malignant tumors arising from the anal canal were included. Patients with secondary anal canal involvement from rectal or perianal skin cancers and metastatic tumors were excluded.Results: There were 22 women and 19 men, age ranging from 33 to 83 years, with a median age of 57 years at diagnosis. Sixteen patients (39%) had localized disease, 21 (51%) had regional disease, and 4 (10%) had metastatic disease at diagnosis. Squamous cell carcinoma (61%) was the most frequent histologic subtype, followed by adenocarcinoma (27%), malignant melanoma (10%), and gastrointestinal stromal tumor (2%). After a median follow-up of 51 (11-169) months for surviving patients, 22 patients were alive and without disease, three were alive with disease, and 19 patients died due to the disease. Histological subtype (P=001), and stage of disease (P=0.002) were prognostic factors for overall survival. The 5-year local control, disease-free, and overall survival rates for all patients were 63.9%, 53%, and 59.4% respectively.Conclusions: This study indicated that squamous cell carcinoma, adenocarcinoma, and malignant melanoma are the most frequent malignant neoplasms in the anal canal. Histological subtype and disease stage are the most important prognostic factors for overall survival in this region.

Background & objective: Primary pleural neoplasms are rare entities compared with the pleural involvement by metastatic carcinoma. The current study aimed at investigating the complete spectrum of pleural neoplasms and differentiating between them with the aid of immunohistochemistry (IHC). Methods: Consecutive pleural biopsy specimens positive for a neoplasm, both primary and metastatic, were included in the study. Diagnosis or a differential diagnosis was suggested on histopathology confirmed by a panel of IHC markers such ascytokeratin(AE1/AE3), epithelial membrane antigen (EMA), vimentin, calretinin, CD34, CD99, SMA, bcl2, S100, CK7, CK20, TTF1, GCDFP, HMB45, LCA, synaptophysin, chromogranin, and naspsin. Results: A total of 35 cases of pleural neoplasms included 15 (42. 9%) primary pleural neoplasms and 20 (57. 1%) metastatic carcinoma. Synovial sarcoma, malignant mesothelioma (MM), and solitary fibrous tumor (SFT) accounted for 14. 2%, 11. 4%, and 8. 5% of metastatic cases, respectively. Epithelioid sarcoma(ES), neuroendocrine carcinoma, and inflammatory myofibroblastic tumor were less common, each contributing to 2. 9% of pleural neoplasms. Among the 20 cases of metastatic carcinoma, 13 were from the lung and 7 from the breast. Lung neoplasms metastasizing to the pleura were adenocarcinoma (n=12) and atypical carcinoid (n=1). Conclusion: Analysis of histopathological pattern along with a panel of appropriate IHC markers distinguished the rare entities of pleural neoplasms essential to determine the prognosis and treatment modality.