Nuclear Lobulation in the Plasma Cells of a Patient with Multiple Myeloma (Bence Jones Type)

Abstract

A 67-year-old female was admitted because of bone pain in July, 1984. Based on the presence of anemia, the elevation of serum creatinine and calcium levels, the depression of serum immunoglobulins, Bence Jonces proteinuria (lambda type, 3.0 g/day), multiple osteolytic lesions and plasmacytosis in the bone marrow, a diagnosis of multiple myeloma of Bence Jones lambda type was made. After chemotherapy with cyclophosphamide and melphalan, her clinical status had been improved in August, 1984. In April, 1986, plasma cells in the bone marrow increased to 80%. The majority of plasma cells in her bone marrow had the indented or lobulated nuclei and some of them were also observed in the peripheral blood. Electron-microscopically, immature plasma cells with dilated cysternae of rough endoplasmic reticulums, multilobulated nuclei and numerous perinuclear cytoplasmic fibrils were observed. The majority of nuclear DNA contents of plasma cells, measured by cytofluorometry, showed the diploid DNA content and no differences existed between the nuclear DNA contents of plasma cells with lobulated nucleus and those with round nucleus. The chromosome numbers ranged from 52 to 53 and a 14 q+chromosome abnormality was observed in 18 of 19 karyotypes examined.
The case presented here has suggested that the clonal selection caused by chemotherapy and/or perinuclear cytoplasmic fibrils may play a role in the development of nuclear lobulation.