Submitting Author: Deeb, George, MD
Institution: Roswell Park Cancer Institute
Additional authors:Vishala Neppalli MD, Bora Baysal PhD MD, Sheila N. Jani Sait PhD, Elizabeth Griffiths MD
Session: AML with myelodysplasia-related changes

The patient is 57-year-old lady who was diagnosed with myelodysplastic syndrome (MDS) treated with azacitidine (a total of 16 cycles) with initial good response but thereafter the patient became transfusion dependent. The patient was referred to our institution for further management. A bone marrow sample was obtained (BM-1, 17 months after outside diagnosis of MDS and pre-lenalidomide therapy) confirming the diagnosis of MDS with isolated del(5q); CBC showed WBC 2.76 x10^9/L, Hemoglobin (Hgb) 7.1 g/dL, and platelt count (Plt) 438 x10^9/L. Lenalidomide therapy was initiated and 10 months later complicated with neutropenia when it was put on hold and then re-instituted two weeks later at lower dose. Fifteen months after the BM-1 sample, second bone marrow sample (BM-2) was obtained; CBC showed WBC 2.00, Hgb 10.1, and Plt 64. The Revlimid dose was further reduced due to persistent neutropenia and thrombocytopenia and thereafter placed on hold. Twenty months after the BM-1 sample, third follow up bone marrow sample (BM-3) was obtained showing progressing disease with excess blasts type 1; CBC showed WBC 1.41, Hgb 8.2, and Plt 11. A rregimen of azacitidine and lenalidomide was initiated.

All evaluated bone marrow and blood smears were Wright-Giemsa stained. The blood smears corresponding to BM-1 had frequent platelets; those of BM-2 and BM-3 had obvious decreased frequency of platelets. Only the blood smear corresponding to BM-3 had rare circulating blasts without Auer rods. The bone marrow aspirate smears showed marked dysplasia involving the trilineage hematopoiesis with increased frequencies of blasts, no Auer rods seen, from 3%, 2%, to 9% in BM-1, BM-2, and BM-3, respectively, increased frequencies of ring sideroblasts from 5%, 35%, to 36% in BM-1, BM-2, and BM-3, respectively; and decreased frequencies of megakaryocytes from hyperplastic in BM-1 to hypoplastic megakaryopoiesis in BM-3.

CD42b immunoperoxidase stain, performed on the FFPE decal iced core biopsy sections of BM-1 to 3, highlights marked dysplastic megakaryocytic hyperplasia in BM-1 and dysplastic but less prominent megakaryopoiesis in BM-3. Reticulin stain on core sections show mild reticulin myelofibrosis in all biopsies. Flow cytometry analyses were performed on samples submitted as bone marrow aspirate from BM-1 to 3, the granulocytes showed slight hypogranulation in analysis BM-1 and more prominent hypogranulation in BM-2 and 3 samples. The myeloblasts had the following immunophenotypic features in BM-1: CD45 (dim), HLA-DR, CD34, CD38, (heterogeneous), CD13, CD33, CD11b (subset), CD7 (subset), and CD117; the following features in BM-2 and 3: CD45 (dim), HLA-DR, CD34, CD38 (subset), CD10 (subset), CD13, CD33, CD56, and CD117, with newly encountered CD10 and CD56 expression and loss of CD7 expression.

Conventional karyotyping and fluorescence in-situ hybridization (FISH) studies using Vysis LSI EGR1/D5S23, D5S721, and Cytocell Del5q probes were performed on the submitted bone marrow aspirate from the three samples.

BM-1 had 46,XX,del(5)(q13q33)[17]/46,XX[3]; BM-2 had 46,XX,del(5)(q13q33) [15] /46,XX[5], and BM-3 had 46,XX,del(5)(q13q33) [20]. The FISH results are reported as the percentage of cells harboring the abnormal signals out of 200 interphase nuclei scored; BM-1 had 47%, BM-2 59%, and BM-3 88%.

Molecular analyses for FLT3 and NPM1 gene mutations were performed on the sample BM-1; wild-type FLT3 and NPM1 genes were detected.

This patient underwent a treatment with a specific chemotherapeutic agent (lenalidomide) with expected good response in patients with myelodysplastic syndrome with isolated del(5q); in despite of the expected good response the disease progressed clinically and changed phenotypically with increased frequency of blasts and profound thrombocytopenia with megakaryocytic hypoplasia in association with apparent persistent identical gross chromosomal changes; the findings are suggestive of selection of resistant clone or clonal evolution/second hit that is not detected by conventional cytogenetics. Molecular studies to identify mutated gene/s that may be implicated in tumor progression and resistance to lenalidomide therapy are being under invistigate in this patient.

Myelodysplastic syndrome with isolated del(5q) progressing on lenalidomide therapy.

Refractory anemia with excess blasts-1 (RAEB-1), progressed from myelodysplastic syndrome with isolated del(5q)

Case 397