Rypka Katelyn, Meisenheimer John, Shaver Rob, Ravishankar Adarsh, Peltola Justin, Mesa Hector, Jacobson-Dunlop Erick, Collier Sigrid, Gaddis Kevin, Goldfarb Noah
Department of Dermatology, University of Minnesota, Minneapolis, Minnesota, United States Department of Dermatology, Minneapolis VA Health Care System, Minneapolis, Minnesota, United States.
Dermatol Online J. 2025 Jun 15;31(3). doi: 10.5070/D331365360.
Mature plasmacytoid dendritic cell proliferation is a condition associated with myeloid neoplasms, most commonly chronic myelomonocytic leukemia. Plasmacytoid dendritic cells can resemble lymphocytes and histiocytes morphologically and immunophenotypically. Mature plasmacytoid dendritic cell proliferation may therefore go unrecognized if the diagnosis is not suspected and appropriate stains for plasmacytoid dendritic cells are not performed. Herein, we present a case of mature plasmacytoid dendritic cell proliferation masquerading clinically and histologically as histiocytoid Sweet syndrome. The patient, who had previously been diagnosed with mature plasmacytoid dendritic cell proliferation that presented as pink, edematous, pruritic papules and plaques, had initially resolved following induction chemotherapy for acute myelomonocytic leukemia. However, he presented later with indurated purpuric plaques on the trunk within weeks of receiving filgrastim for neutropenia. Biopsies demonstrated marked dermal edema, interstitial, superficial, and deep infiltrate with histiocytoid appearing cells concerning for histiocytoid Sweet syndrome. Further work-up demonstrated that the infiltrate was predominantly composed of CD3-, CD4+, CD34-, CD123+, CD56-, CD68-, myeloperoxidase negative mononuclear cells consistent with mature plasmacytoid dendritic cell proliferation. This case demonstrates that MPDCP should be considered in the differential diagnosis of eruptions that clinically and histologically look like histiocytoid Sweet syndrome but stain negatively for myeloperoxidase.
成熟浆细胞样树突状细胞增殖是一种与髓系肿瘤相关的病症，最常见于慢性粒单核细胞白血病。浆细胞样树突状细胞在形态学和免疫表型上可类似于淋巴细胞和组织细胞。因此，如果未怀疑诊断且未对浆细胞样树突状细胞进行适当染色，成熟浆细胞样树突状细胞增殖可能无法被识别。在此，我们报告一例成熟浆细胞样树突状细胞增殖病例，其在临床和组织学上伪装为组织细胞样Sweet综合征。该患者先前被诊断为成熟浆细胞样树突状细胞增殖，表现为粉红色、水肿性、瘙痒性丘疹和斑块，在接受急性粒单核细胞白血病诱导化疗后最初病情缓解。然而，他在因中性粒细胞减少接受非格司亭治疗数周后，躯干出现硬结性紫癜斑块。活检显示明显的真皮水肿，间质、浅层和深层有组织细胞样细胞浸润，疑似组织细胞样Sweet综合征。进一步检查表明，浸润主要由CD3 -、CD4 +、CD34 -、CD123 +、CD56 -、CD68 -、髓过氧化物酶阴性的单核细胞组成，符合成熟浆细胞样树突状细胞增殖。该病例表明，在临床和组织学上看似组织细胞样Sweet综合征但髓过氧化物酶染色阴性的皮疹鉴别诊断中应考虑成熟浆细胞样树突状细胞增殖。
