A case of surgical treatment for primary BCL2-“negative” follicular lymphoma without t(14;18) in early stage of the submandibular lymph node

Follicular lymphoma (FL) is characterized by the t(14;18)(q32;q21) resulting in constitutive overexpression of BCL2. We report an unusual case of early stage of FL without t(14;18)(q32;q21). The patient was a 74-year-old Japanese female who presented to our hospital with a complaint of swelling of the submandibular region. The lymph node was successfully removed by a minimally invasive procedure. Giemsa chromosome banding stain showed no abnormality. A flow cytometry analysis of the lymphoma cells in lymph node showed the following results: CD19(+), CD20(+), CD23(+), and immunoglobulin light chains kappa(+) and lambda(−). Immunophenotypes of the lymphoma cells were BCL2(−), MUM1(−), CD10(+), and BCL6(+). We diagnosed an early stage neck FL stage I without t(14;18)(q32;q21). The patient was managed successfully with surgical excision without signs of recurrence for 1 year. This case suggests genetically distinct subgroup of BCL2-negative, surgical treatment, and new insights into the pathogenesis of FL.