Dr Mohammed on the Challenges of Diagnosing BPDCN

Turab J. Mohammed, MD, hematology/oncology fellow, Moffitt Cancer Center, discusses challenges associated with the diagnosis of blastic plasmacytoid dendritic cell neoplasm (BPDCN), and strategies to improve early diagnosis of this disease.

BPDCN is characterized as a rare and aggressive hematologic malignancy, Mohammed begins. It often remains undiagnosed, particularly in patients whose only disease indicator is variable skin involvement, Mohammed states. Cutaneous lesions can manifest as brown or purple lesions, tumor-like nodules, or rapidly appearing bruises on the skin without explanation.

When these patients first present symptoms in clinical practice, they are typically sent to either dermatologists or their primary care physician for initial diagnosis, Mohammed explains. Patients who are suspected of having BPDCN will then be referred to a hematologist, and will undergo a skin biopsy, he adds. In general, skin biopsies with immunohistochemical specific markers are an important first step in the diagnosis of patients with BPDCN, as it can elucidate both the histology and immunophenotype of this disease, Mohammed details.

Additional diagnostic tools include molecular imaging, which can help identify splenomegaly or the degree of lymph node involvement or adenopathy, Mohammed continues. To complete the work-up, a bone marrow biopsy followed by ancillary flow cytometry can also be conducted for patients who do not display obvious cytopenia, he adds. This strategy aids BPDCN diagnosis by potentially revealing common mutational drivers associated with the disease. These can include CD123, CD4, and CD56, which are expressed on the cell surface, Mohammed details.

Although a majority of patients with BPDCN express these surface markers, a small percentage of patients have infrequent or decreased expression, which can make them difficult to diagnose, Mohammed notes. Additional testing should be performed in this population to identify potential biomarkers of plasmacytoid dendritic cell origin, such as CD303, CD304, and TCL1, Mohammed concludes.