Investigation of NPM1 mutation frequency in cutaneous blastic plasmacytoid dendritic cell neoplasms.
Complex karyotype is more frequent in blastic plasmacytoid dendritic cell neoplasm than myeloid sarcoma.
Investigation of NPM1 mutation frequency in cutaneous blastic plasmacytoid dendritic cell neoplasms.
Blastic plasmacytoid dendritic cell neoplasm (blastic plasmacytoid dendritic cell neoplasm) and acute myeloid leukemia (acute myeloid leukemia) show overlapping clinicopathological presentations, which makes it challenging to differentiate on a small skin biopsy.
We aimed to investigate NPM1 mutations in cutaneous blastic plasmacytoid dendritic cell neoplasm cases and compare them with cutaneous NPM1 positive leukemia cutis cases.
From a multi-institutional search, we identified and analyzed 13 cases of cutaneous blastic plasmacytoid dendritic cell neoplasm and 19 cases of cutaneous myeloid sarcoma (7 of which were primary leukemia cutis) with NPM1 mutations.
over a third of blastic plasmacytoid dendritic cell neoplasm cases show complex karyotype, more than twice the rate in myeloid sarcoma
Blastic plasmacytoid dendritic cell neoplasm patients presented at an older age, with lower white blood cell count, higher hemoglobin level, and elevated platelets counts as compared to cutaneous myeloid sarcoma patients (p < 0.05).
The bone marrow of patients in both groups was similarly involved at the time of diagnosis with no significant difference in rate; however, the percentage of involvement was significantly different among the two groups.
Mutational profile differed among the two groups with absence of NPM1 mutations in blastic plasmacytoid dendritic cell neoplasm cases.
We find that blastic plasmacytoid dendritic cell neoplasm patients present in a similar way to cutaneous acute myeloid leukemia patients but appear to uniformly lack NPM1 mutations.
Our study suggests that NPM1 can be used as a surrogate immunohistochemical stain to differentiate this rare disease from myeloid sarcoma in a rapid and cost-effective method.