| Session: Extramedullary manifestation of neoplastic myeloid disorder |
| Case number: 024 |
Submitter(s): Aliyah Rahemtullah, Martin K. Selig, Paola Dal Cin, Robert P. Hasserjian.
Clinical history
A 25-year-old woman with a history of Chernobyl radiation exposure at age 6, but without prior malignancy, presented with an enlarging mass of the right submandibular gland accompanied by sore throat and 10 lb weight loss. Physical exam revealed another 2 cm firm mass in the left breast. Initial CBC: WBC 7,700/mm3, Hgb 14.4 g/dL, Plts 291,000/mm3; Differential: 74% polys, 19% lymphs, 4% monos, 2% eos, 1% basos. The patient was not on any medications.
Details of gross/microscopic pathology:
A 5 cm lobulated, tan, firm mass replaced the salivary gland and extended into adjacent lymph nodes. The salivary gland lobules contained a diffuse infiltrate of large cells with folded nuclei, vesicular chromatin and moderately abundant pink cytoplasm surrounding residual ducts and acini.[figure1] Numerous admixed mature eosinophils and eosinophil precursors were present.[figure2] EM on glutaraldehyde-fixed tissue revealed cells with high N/C ratio, clefted nuclei and dispersed chromatin corresponding to neoplastic cells,[figure3] and cells with lobated nuclei and prominent cytoplasmic granules consistent with admixed eosinophils.[figure4] Core biopsy of the breast mass revealed a similar cellular infiltrate surrounding sclerotic ducts.[figure5] Bone marrow biopsy (B+ fixed, RapidCal-Immuno decalcified) and aspirate showed normocellular marrow with maturing trilineage hematopoiesis and 1% blasts.[figure6] Peripheral blood smear showed mature leukocytes.
Immunophenotype (flow cytometry/immunohistochemistry):
Immunohistochemistry performed on the salivary gland and breast masses showed the large cells to be positive for CD45, CD34, CD117, myeloperoxidase (MPO), lysozyme, CD43 and CD68.[figure7] Stains for B and T-cell markers highlighted scattered small cells. Flow cytometry of the salivary gland mass detected a population of CD45dim+CD33+CD13+MPO+CD14-CD117+CD34+ myeloblasts with high forward scatter comprising 44% of all cells.[figure8] Bone marrow aspirate flow cytometry showed 1% myeloblasts.
Cytogenetics:
As leukemia was unsuspected at surgery, no fresh tissue of the salivary gland was sent for karyotyping. Establishing the specific WHO Classification required directed FISH on paraffin-embedded tissue. FISH with a dual color break apart probe for the CBFB locus at 16q22 revealed a rearrangement in 31/55 (56%) nuclei.[figure9] Bone marrow cytogenetics revealed a normal female karyotype.
Molecular analysis:
Not performed.
Interesting feature(s) of submitted case:
Myeloid sarcoma is a rare presentation of AML; isolated salivary gland and breast masses are unusual. The patient received standard AML induction chemotherapy, with biopsy-confirmed complete regression of the breast mass post-therapy. The lack of bone marrow involvement precluded definitive evaluation for minimal residual disease in this case with exclusive extramedullary involvement.
Proposed diagnosis:
AML with inv(16) (FAB AML-M4Eo) presenting as myeloid sarcoma of the submandibular gland and breast without bone marrow involvement.
Panel diagnosis:
agree with proposed diagnosis
Comments:
Panel comment: foci of plasmacytoid dendritic cells present. Stains performed by the panel: CD123+, HECA focally +, PDGFRa -, NPM- (+in nuclei). Additional comment from the submitter: Immunohistochemistry for CD2 was performed in this case and was found to be negative on the myeloid blasts in the myeloid sarcoma, with positive staining in scattered small T cells.
PowerPoint:
Presentation Link
Images:
 |
Figure 1 |
 |
Figure 2 |
 |
Figure 3 |
 |
Figure 4 |
 |
Figure 5 |
 |
Figure 6 |
 |
Figure 7 |
 |
Figure 8 |
 |
Figure 9 |
Back to Top
Back to Cases by Session
Back to Cases by Contact Submitter