Current understanding of the role and regulation of miRNAs in Burkitt lymphoma.

Since its discovery in 1958, Burkitt lymphoma (BL) has been extensively studied and has become a model for tumorigenesis, but its pathogenesis has not been completely explained and understood yet. The aim of this review was to summarize the current knowledge about BL and, in particular, to discuss the role of miRNAs in its pathogenesis and their possible use as diagnostic and prognostic indicators. The impact of viral-encoded miRNAs is also discussed, with the Epstein-Barr infection being almost invariably detected in the endemic variant of this tumor.

Unusual presentation of primary T-cell lymphoblastic lymphoma: description of two cases.

BACKGROUND: T-cell lymphoblastic lymphoma comprises approximately 85-90% of all lymphoblastic lymphomas. It often arises as a mediastinal mass, and with bone marrow involvement. Presentation at other sites without nodal or mediastinal localization is uncommon. CASE REPORT: We describe clinical, histologic, immunohistochemical, and molecular features of two cases of primary T-cell lymphoblastic lymphoma arising respectively in uterine corpus and testis. The tumors were composed by medium to large cells, exhibiting a diffuse pattern of growth but sometimes forming indian files or pseudo-rosettes. The neoplastic cells strongly expressed TdT and T-cell markers in both uterine corpus and testis. However, the testis case also showed aberrant expression of B-cell markers, thus molecular biology was necessary to achieve a final diagnosis. T-cell receptor gene rearrangement analysis identified a T-cell origin. CONCLUSIONS: To the best of our knowledge, only one doubtful previous case of primary uterine T-cell lymphoblastic lymphoma and no previous cases of primary testicular T-cell lymphoblastic lymphoma have been reported. Due to the morphology of neoplastic cells, a challenging differential diagnosis with all the tumors belonging to the so-called small round blue cell tumor category is mandatory. In ambiguous lineage cases, molecular biology may represent an adequate tool to confirm diagnosis. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1559880973128230.