Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a very rare and aggressive hematologic malignancy and to date, only one case of presented with periorbital ecchymosis and subconjunctival hemorrhage (SCH) has been reported. Here, we would like to introduce the first Korean case of the BPDCN presenting as periorbital ecchymosis and massive SCH. Written informed consent for publication of the research details and clinical images was obtained from the patient.

An 88-year-old woman visited our clinic with periorbital ecchymosis and massive SCH. These signs first started in her right eye a month and a half ago, and the same signs appeared in her left eye a month later. She had no history of trauma or underlying medical conditions except hypertension. Her corrected visual acuity was 20 / 100 in the right eye and hand motion in the left eye due to preexisting macular degeneration. Periorbital swelling, ecchymosis and SCH were seen in both eyes, and the SCH was so massive that it covered the cornea. (Fig. 1A-1C). The lesions were very hard and painless in nature. The blood count was normal, and the coagulation test was within the normal range. An orbital magnetic resonance imaging showed bilateral diffuse enhancing mass with low apparent diffusion coefficient in eyelid, lacrimal gland, lacrimal sac and nasolacrimal duct (Fig. 1D, 1E). An incisional biopsy was performed and on pathologic examination, numerous atypical plasmacytoid cells were found (Fig. 1F) and were positive for CD123, CD4, CD56, and TCL1 (Fig. 1G-1J), leading to the diagnosis of BPDCN. She also had breast nodule and biopsy diagnosed it as BPDCN. We referred the patient to the Department of Hematology-Oncology for chemotherapy.

BPDCN was adopted in the 2008 World Health Organization (WHO) Classification of Tumors of Hematopoietic and Lymphoid Tissues under the category “acute myeloid leukemia and related precursor neoplasms” [1] and was listed as its own category in the 2016 WHO revision [2]. The most important sign of BPDCN is bruise-like skin lesions [3]. The skin lesions of reported cases were mostly found on the trunk and limbs [4], but rarely on the periorbital and conjunctival regions. Since BPDCN can be misdiagnosed as non-Hodgkin lymphoma or acute myeloid leukemia or melanoma, definitive diagnosis should be made by histopathologic examination. BPDCN usually exhibits a specific immunophenotype that must be confirmed by either immunohistochemistry or by flow cytometry. The diagnosis relies on the demonstration of CD123, CD4, and CD56 positivity by tumor cells, together with markers more restricted to plasmacytoid dendritic cells such as TCF4, TCL1, CD303, or CD304 and lack of expression of markers of CD3, CD14, CD19, CD34, lysozyme, and myeloperoxidase [5].

In conclusion, we present a first case of BPDCN of periorbital and conjunctival lesions in Korea, which is an exceedingly rare neoplasm. Although BPDCN is extremely rare, it should be considered as a differential diagnosis of nontraumatic periorbital ecchymosis and massive SCH.