[CD5- and CD10-positive MYC and BCL2 double-expressor diffuse large B-cell lymphoma with MYD88^L265P mutation: a case report and literature review]

A 75-year-old man who had lymphadenopathy was admitted to our hospital. Histopathological examination of cervical lymph node biopsy specimens showed diffuse proliferation of lymphoma cells with large nuclei. In immunohistochemistry, the lymphoma cells were positive for CD5, CD10, CD20, BCL2, BCL6, and MYC. The patient was diagnosed with CD5- and CD10-positive diffuse large B-cell lymphoma (DLBCL). MYD88^L265P mutations have been detected in DLBCL. Partial response was achieved after six courses of R-THP-COP therapy. However, the patient died because of disease progression 18 months after the diagnosis. On autopsy, lymphoma cells were found in the lymph nodes throughout the body, central nervous system, adrenals, and skin. CD5- and CD10-positive DLBCL account for 0.5-1% of DLBCL cases and have a very poor disease prognosis. This is a rare case of CD5- and CD10-positive DLBCL with MYC and BCL2 expressions harboring MYD88^L265P mutation.