Cutaneous blastic plasmacytoid dendritic cell neoplasm: successful palliative treatment with oral prednisone in an elderly patient
Authors: C. Vassallo, C. Pezzini, A. Carugno, F. Derlino, G. Croci, M. Paulli, G. Borroni
Journal: British Journal of Dermatology (2014)

Funding sources: no external funding. Conflicts of interest: none declared. Dear Editor, Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare haematological malignancy, previously referred to as ‘blastic NK‐cell lymphoma/leukemia’1 or ‘agranular CD4+/CD56+ haematodermic neoplasm’,2 characterized by proliferation of precursors of plasmacytoid dendritic cells (pDC, CD4+ CD56+) and by prominent cutaneous involvement. The prognosis of BPDCN is remarkably poor, especially in elderly patients, with a nearly constant peripheral blood, bone marrow and lymph node dissemination, even after aggressive chemotherapy.3 An 83‐year‐old man was referred to the Department of Dermatology for a 2‐month progressively enlarging plaque on his scalp, followed by the development of a cervical lymphadenopathy and erythematous nodules on his back. The patient's past medical history included chronic renal failure, ischaemic heart disease, glaucoma of the right eye, hepatitis C virus infection and a myelodysplastic syndrome requiring no treatment. At the time of observation the patient presented with infiltrated, coalescent plaques involving his whole scalp, with prominent ulcero‐necrotic features (Fig. 1a); erythematous nodules on his trunk were also evident. The lesions were very distressing due to the intense pain, weeping, bleeding and fetor, causing marked prostration of the patient. A diagnosis of cutaneous lymphoma was considered, and skin biopsies were performed for histological and immunohistochemical studies. Histopathological findings were characterized by an infiltrate of medium‐sized cells, with scant cytoplasm, small nucleoli and vesciculous nuclei (Fig. 2a,b); the infiltrate showed no signs of epidermotropism, and extended throughout the papillary and reticular dermis, reaching the subcutaneous tissue. Immunostaining with anti CD2, CD4, CD7, CD43, CD56, CD123, TdT, TCL1 and bcl‐2 antibodies was positive (Fig. 2c,d). A proliferation of interferon (IFN)‐1‐producing pDC was found, and a final diagnosis of BPDCN was made. Disease staging was performed and extracutaneous involvement was investigated through radiological and pathological studies: peripheral blood and bone marrow showed no neoplastic localizations, while a cervical lymph node enlargement, with splenomegaly and hepatic hypercaptation could be detected on computed tomography scan. Due to the patient's advanced age and comorbidities, no multi‐agent chemotherapies were administered, according to counselling from haematologists. To reduce his suffering and local inflammation, a daily 25 mg prednisone therapy was started, together with analgesic and antibiotic treatments, with prompt cutaneous improvement. Eight months after diagnosis he presented a striking cutaneous healing of both scalp and trunk lesions, with complete remission of the ulcerated plaques, resulting in a superficial scar (Fig. 1b,c). Relief of the pain quickly occurred and the patient's quality of life greatly improved. He also underwent a liver biopsy, which was consistent with hepatocellular carcinoma, subsequently treated with local alcoholization. Poorly controlled steroid‐induced diabetes occurred and prednisone therapy was stopped; 1 month later, the patient developed multiple erythematous nodules on his scalp, histologically consistent with a recurrence of BPDCN. Oral prednisone was reintroduced with prompt benefits and partial healing of the nodules; a lower‐dosage (12·5 mg) systemic steroid therapy together with insulin treatment is ongoing 1 year after diagnosis. No further cutaneous lesions occurred.