Unique Recognizable Histopathologic Variant of Palisaded Neutrophilic and Granulomatous Dermatitis that Is Associated With SRSF2-Mutated Chronic Myelomonocytic Leukemia: Case Report and Review of the Literature.

Palisaded neutrophilic and granulomatous dermatitis (PNGD) represents a cutaneous histopathologic reaction spectrum associated with several underlying disorders. Few cases of PNGD have been associated with chronic myelomonocytic leukemia (CMML), a malignant hematopoietic disorder with features in between those of a myeloproliferative neoplasm and myelodysplastic syndrome. We present a patient with a generalized papular skin reaction involving the neck, chest, and shoulders with histomorphological features on the spectrum of PNGD. Subsequent laboratory workup demonstrated a persistent mild monocytosis, raising concern for CMML. The diagnosis was ultimately confirmed with a bone marrow biopsy and associated mutational analysis through next-generation sequencing which identified deleterious variants in SRSF2, IDH2, and ASXL1. The findings in this case strengthen the previously made association between PNGD and SRSF2-mutated CMML and may help better define a unique recognizable clinical-histopathological-molecular subtype for dermatopathologists.