Objectives Leukemia cutis is a conflicting term to describe neoplastic hematopoietic
infiltrates in the skin. Cutaneous myeloid or lymphoid proliferations often present
a serious differential diagnostic challenge for pathologists.Methods This review aims
to outline the confusion associated with the term leukemia cutis and discuss in detail
the foremost common differential diagnoses in daily practice. The review is based
on a summary of the relevant literature as well as on the authors' experience.Results
It addresses precursor cell myeloid and lymphoid tumors that are strictly considered
true leukemia cutis but also more mature neoplasms, including some recently described
mature extramedullary myeloid proliferations. Finally, a practical, comprehensive
stepwise approach combining traditional immunohistochemical marker panels, novel lineage-
or mutational-specific markers, and other ancillary tests is suggested to reach an
entity-specific diagnosis.Conclusion The proper combination of ancillary techniques
can help the pathologist to provide an accurate diagnosis of these challenging skin
lesions.
