A rare composite karyotype in a Filipino with diffuse large B-cell cell lymphoma
Non-Hodgkin's lymphomas (NHLs) are neoplasms of the immune system arising almost anywhere in the body, but most frequently developing in lymph nodes. Diffuse large B-cell lymphoma is the most common of the NHLs, reportedly comprising 30% of the newly diagnosed cases. Clinico-pathologic features of the disease are very heterogeneous, making classification quite difficult. We present a 17-year old female with multiple enlarged mesenteric lymph nodes. Histopathological analysis of the tumor showed effacement of nodal architecture by a diffuse population of large cells with vesicular nuclei, prominent centrally located nucleoli, finely dispersed chromatin and scanty cytoplasm. Occasional histiocytes were also seen interspersed among tumor cells. Immnuohistochemical staining demonstrated CD19 and CD20 reactivity with surface lambda light chain consistent with B-cell lymphoma. Cytogenetic analysis carried out from primary culture of biopsy sample revealed great karyotypic heterogeneity. A composite karyotype was observed and is as follows;
45-52,XX,+X,add(1)(p36),del(3)(p21),der(3)t(3;17)(p26;q11),+4,+5,
-6,+7,+8,+9,+10,-17,-18,-19,-20,+21,+1-3mar(24). In the absence of mulicolor FISH or SKY this karyotype may be considered tentative. Many of the earlier cytogenetic findings on NHL reported translocation involving two chromosomes. The present case reveals numerous abnormalities and may point to multiple gene involvement in the development of the malignancy.