58° Congresso Nazionale SCIVAC: Oncologia veterinaria

58° Congresso Nazionale SCIVAC • Milano, 7-9 Marzo 2008 • Oncologia veterinaria - Alle soglie del III Millennio
increased N/C ratio. The nuclear chromatin was dense and fine and one or
more distinct nucleoli were visible. Cytoplasmic microvacuolizations, basophilia
and blebbing were reported. Based on these findings, the sample was
suggestive of an acute myeloid leukemia probably of megakaryoblastic origin.
The latter revealed the same leukemic cells scattered in the splenic parenchyma.
In order to precisely characterize this type of myeloproliferative
disorder, samples (blood and bone marrow) were submitted to a referral laboratory
for flow cytometry analysis.
The immunological panel revealed a 7,2% CD3 positivity (T lymphocytes),
5,8% CD79 (panB-lymphocytes), 2,3% CD34 (blast cells), 4,0% CD14 (monocytes),
64,5% CD9 (platelets), 59,5% CD61 (platelets), 17,7% CD18 (b2-
integrins). Based on the immunological profile a diagnosis of acute megakaryoblastic
leukemia was made.
A trasfusion of 250 ml of fresh canine blood was given. Ampicillin (20 mg/kg
TID) and metronidazol (7 mg/kg TID) were administered. The blood trasfusion
increased the PCV to 18,5%. Following stabilization, chemotherapy with
100 mg/m 2 of cytosine arabinoside divided 4 times daily was started. The dog
did not respond to chemotherapy and after four days Hct dropped again to
12%. At this time the owners elected to euthanize the dog.
Discussion. The lineage of an immature neoplastic population can not be determined
morphologically alone. Nowadays the association between morphological
and immunophenotypical evaluation can, with no doubt, grows
the accuracy of the diagnosis. Compared to immunohistochemistry, flow
cytometry can be used with blood and/or bone marrow samples with no need
of tissue or core biopsy. Furthermore flow cytometry allows the evaluation
of several parameters in few seconds and provides the clinician of daily results.
In the present work, flow cytometry has established megakaryocytic lineage
showing the presence of two megakaryocyte/platelet associated antigens
(CD9, CD61). In human medicine CD9 is commonly used as a platelets
and megakaryocytes marker. There is evidence of cross-reactivity of human
anti-CD9 monoclonal antibody with canine samples. In particular, to
our knowledge, the use of CD9 was never described before, for this use in
the dog.
Bibliografia disponibile su richiesta all’autore.
Indirizzo per la corrispondenza:
Fabio Valentini
Ospedale Veterinario “Gregorio VII”
Piazza di Villa Carpegna, 52 - 00165 Roma
Fax 06-66068250 - E-mail: f.valentini@email.it
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