CD13+ AML

Robert Pyle (pyle@smtpgw.kfshrc.edu.sa)
Wed, 22 Jan 97 10:33:01 SAU

Thanks to those who have already replied to my initial question on the
apparent case of AML that was positive for only CD13. Most replies
asked for further information which is now available.

Markers employed in the study:
CD2,CD3,CD4,CD5,CD7,CD8,CD10,CD11c,CD13,CD14,CD19,CD20,CD22,CD25,CD33,
CD45, HLA-DR. No material was available for additional studies.

Cytochemistry employed in the study: PAS, SBB, Combined esterase

Immunocytochemistry performed on sections: extensive battery not
further detailed except a partial positivity for OML-3.

Bone Marrow Morphology: Large, non-cohesive, mononuclear cells. No
auer rods noted but some granulation was described. Blast cells
comprised a diffuse infiltrate on this random bone marrow. No blast
cells could be demonstrated in the peripheral blood.

Clinical Presentation: patient presented with bilateral renal masses
and a deep iliac mass. Fine needle aspirates of the mass suggested
possible myeloid origin. Bone marrow was performed demonstrating the
above mentioned blast population.

For all the above testing, the only positivity noted was for CD13 and
the OML-3. I am not totally familiar with the OML-3 antibody but I
know the histo people use it for Ewings Sarcoma investigation. It is
my understanding however, that the antibody was raised from an AML
cell line making us wonder a bit.

The suggestions that this may be a non-hematopoietic tumor is well
taken and we are currently moving toward that diagnosis. By flow
cytometry, cytochemistry, immunohistochemistry, and morphology we are
ruling our small round cell tumors such as Ewings Sarcoma and
Neuroblastoma. Does anyone else know of other non-hematopoietic tumors
that they have seen label postive for CD13? I would note that the
positivity that was seen by flow cytometry was only a partial positive
for CD13. Not all cells uniformly labeled with CD13.

Your input would be much appreciated.

Haywood Pyle
pyle@kfshrc.edu.sa