Contributed by Teresa M LaCaria, MD and Sandra Kaplan, MD
Published on line in June 2006
The patient is a 56-year-old female with a history of IgG-kappa multiple myeloma diagnosed initially at an outside institution. She received conventional chemotherapy and autologous peripheral blood stem cell transplant in the following year. Five years after initial diagnosis, she presents to our institution with anemia (Hgb 8.9 g/dl, Hct 25.6%) and leukocytosis (WBC 22.5 x 109/L).
A peripheral blood smear demonstrated numerous plasmacytoid cells with eccentric nuclei, distinct nucleoli, and moderate cytoplasm. These cells comprised 56% of peripheral blood leukocytes, and ranged from large immature forms with dispersed chromatin to mature forms with clumped chromatin and more abundant cytoplasm. Prominent rouleaux formation was also appreciated on the smear [Figures 1, 2 and 3]. A bone marrow aspirate showed a predominance of plasmacytoid cells (68%) as well. These marrow cells had irregular nuclear contours and prominent nucleoli, and some multi-nucleate forms were also noted [Figures 4, 5, 6, and 7]. Although the patient's marrow was normocellular for age (approximately 50% cellularity), infiltration of the marrow space with atypical cells was observed on biopsy sections [Figures 8 and 9].
Flow cytometry was performed on peripheral blood and bone marrow. Peripheral blood analysis demonstrated a large population of kappa-restricted plasma cells (approximately 50%) that co-expressed CD138 and CD56 [Figures 10 and 11]. Bone marrow analysis revealed a virtually identical immunophenotype.
Cytogenetic studies performed on bone marrow revealed a mosaic abnormal female karyotype with an apparently normal cell line, and a second cell line with multiple consistent abnormalities including monosomy 13. Fluorescence in-situ hybridization (FISH) demonstrated loss of 13q14.3 and 13q34 in 138 of 216 cells examined (63.9%).