| Session: Ph- chronic myeloproliferative disease |
| Case number: 106 |
Submitter(s): James R. Cook.
Clinical history
The patient is a 26 year old man who was diagnosed with papillary thyroid carcinoma on FNA of a thyroid mass. A pre-operative CBC displayed leukocytosis with marked eosinophilia (absolute eosinophil count: 14x103 /uL). Eosinophilia was persistent following thyroidectomy, and a bone marrow biopsy was performed. The tryptase level was elevated. Following diagnosis (as described below), the patient was treated with imatinib with normalization of the CBC.
CBC: WBC 22.6x103/uL; Hgb 15.2 g/dL; Plt 236x103/uL
Diff: Segs: 8%; Lymphs: 26%; Monos: 2%; Eos: 62%; Basos: 2%
Tryptase: 44.3 ug/L (normal: 1.9 - 13.5 ug/L).
Details of gross/microscopic pathology:
Bone marrow aspirate:
Differential: Blasts 2%; Promyelo 3%; Myelo/meta/band/segs 45%; Eos 13%; Baso 0%; Mono 0%; Erythroid 14%; Lymphocytes 22%; Plasma cells 1%
Morphology: Prominent eosinophilia including atypical eosinophil precursors with basophilic granules.
Bone marrow biopsy:
Normocellular marrow (70%) with myeloid predominance and areas with marked eosinophilia.
Immunophenotype (flow cytometry/immunohistochemistry):
Peripheral blood flow cytometry: Heterogeneous T-cells and polytypic B-cells, with no evidence of a lymphoproliferative disorder.
Bone marrow biopsy: Tryptase immunohistochemistry identifies mildly increased, scattered, often spindled mast cells that appear to coexpress CD25.
Cytogenetics:
Bone marrow: 46,XY[20].
Molecular analysis:
FISH studies: Positive for CHIC2 (4q12) deletion, consistent with FIP1L1-PDGFRA fusion. Negative for BCR/ABL
RT-PCR: Positive for FIP1L1-PDGFRA fusion.
Interesting feature(s) of submitted case:
1) Diagnosis of this uncommon entity requires a molecular approach (RT-PCR or FISH) in the evaluation of unexplained eosinophilia.
2) Cases such as this meet current WHO criteria for classification as either chronic eosinophilic leukemia or systemic mastocytosis, highlighting the need for refinement of current classification systems.
Proposed diagnosis:
FIP1L1-PDGFRA positive chronic eosinophilic leukemia
(Alternate: systemic mastocytosis with eosinophilia and FIP1L1-PDGFRA fusion).
Panel diagnosis:
agree with proposed diagnosis
Comments:
Panel comment: Diagnosis of SM is probable because there is a significant increase of spindle-shaped mast cells with aberrant expression of CD25 (performed by the panel). However, compact infiltrates and D816V (performed by the panel) were not detectable. Spindle-shaped loosely scattered CD25+ mast cells would also fit with CEL.
Images:
 |
Figure 1 |
 |
Figure 2 |
 |
Figure 3 |
 |
Figure 4 |
 |
Figure 5 |
 |
Figure 6 |
 |
Figure 7 |
 |
Figure 8 |
Back to Top
Back to Cases by Session
Back to Cases by Contact Submitter