The curious case of HLA-DR-positive APL

The triad of weak/absent CD34, negative HLA-DR expression, and positivity to CD117 is pathognomonic for the diagnosis of acute promyelocytic leukemia. However, in rare cases, strong positivity to HLD-DR and CD34 may be noted.

CD34 expression and the outcome of nucleophosmin 1-mutated acute myeloid leukemia

CD34 positivity has been considered as an adverse prognostic factor in acute myeloid leukemia (AML). Although nucleophosmin 1-mutated (NPM1m) AML is usually CD34 negative, this marker may be expressed at diagnosis or acquired at relapse in a variable number of cases. Our objective was to ascertain if CD34 expression has any influence on the general outcome of this form of acute leukemia. Analysis of clinical outcome (complete remissions, relapses, disease-free survival, and overall survival) was performed depending on the degree of expression of CD34 determined by flow cytometry, in 67 adult patients with NPM1m AML. CD34 expression did not have any influence on the variables analyzed whatever the percentage of blasts expressing this marker. In contrast to other forms of AML, CD34 expression is not an unfavorable prognostic factor in NPM1m AML, neither at diagnosis nor at relapse.

Multiple clustered dermatofibroma presenting in a segmental distribution

Multiple dermatofibromas is a rare entity consisting of more than fifteen lesions. Multiple clustered dermatofibroma is a distinct variant of multiple dermatofibromas and is defined as a well-demarcated plaque composed of individual dermatofibromas. We report a 16-year-old boy with multiple clustered dermatofibroma in a segmental distribution, which has previously not been reported in the literature.