Case 8

Submitting Author: Soma, Lori, MD
Institution: University of Washington and Diagnostic Pathology Medical Group
Additional authors:Zarir Karanjawal M.D. Ph.D., Michael Carroll M.D.
Session: AML secondary to myeloproliferative neoplasms and other types of disease progression in MPN

Click for virtual slide 1

HISTORY

43 year old male with a history of Crohn's disease and papillary thyroid carcinoma presents with marked leukocytosis (147K).

DETAILS

2011. Bone marrow aspirate and biopsy, iliac crest (MGG, Bouin's fixative): Markedly hypercellular marrow with marked granulocytic predominance. Blasts not increased. Mildly increased eosinophils.

Peripheral blood (MGG): Markedly leukocytosis with leukoerythroblastic picture, 3% circulating blasts and normochromic normocytic anemia

2012. Bone marrow aspirate and biopsy, iliac crest (MGG, Bouin's fixative); Hypercellular marrow with granulocytic predominance and 28% blasts.

Peripheral Blood (MGG): 46% circulating blasts.

IMMUNOHISTOCHEMISTRY AND FLOW CYTOMETRY

2011 Flow Cytometry: No increased or abnormal myeloid blast population

2012 Flow Cytometry: Approximately 20% myeloid blasts expressing CD13, CD33, CD34 and subset CD117, MPO, HLA-DR

CYTOGENETIC FINDINGS

2011. Classical cytogenetic studies: 46,XY,t(9;22)(q34;q11.2)[20]

Fluorescence in situ hybridization: negative for rearrangement of PDGRβ, PDGFα/FIP1L1 fusion, and CBFα rearrangement

2012. Classical cytogenetic studies: 46,XY,t(9;22)(q34;q11.2)[4]/46,idem,inv(16)(p13.2q22)[5]/46,XY[1]

MOLECULAR FINDINGS

2011: none

2012: c-KIT mutation negative (exons 8 and 17)

INTERESTING FEATURES

Inversion 16 in blast phase chronic myelogenous leukemia is uncommon, and those reported tend to have a worse prognosis compared to de novo acute myeloid leukemia with inversion 16. KIT mutations have not been looked at extensively in CML blast phase with inversion 16, although this case is negative.

PROPOSED DIAGNOSIS

2011: Chronic myelogenous leukemia, BCR-ABL1 positive

2012: Chronic myelogeneous leukemia, BCR-ABL1 positive, blast phase with inversion 16(p13.2q22)

CONSENSUS DIAGNOSIS

Chronic myelogenous leukemia, BCR-ABL1 positive, blast phase with inv(16)(p13.2q22); CBFB-MYH11 and t(9;22)(q34;q11.2); BCR-ABL1