Acta Dermato-Venereologica 97-6 97-6CompleteContent | Page 22

747 Expression of Mucin 1 in Mycosis Fungoides Tumour Cells: A Case Report Takushi SHIRAI 1 , Yukiko KINIWA 1 *, Shiho ASAKA 2 , Yasuyo SHIMOJO 2 , Fuminao KAMIJO 1 and Ryuhei OKUYAMA 1 Department of Dermatology, and 2 Division of Clinical Investigation, Shinshu Univerisity School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan. E-mail: [email protected] 1 Accepted Feb 20, 2017; Epub ahead of print Feb 20, 2017 Mucin 1 (MUC1), a member of the mucin family, is a highly glycosylated transmembrane protein normally present on the luminal surface of secretory glands (1). Overexpression of MUC1 in tumour cells and elevated serum MUC1 level have been reported in patients with cutaneous T-cell lymphoma (CTCL) (2, 3). We report here a patient with increased serum MUC1 level and aberrant MUC1 expression in the tumour cells of mycosis fungoides (MF), the most common subtype of primary cutaneous T-cell lymphoma. CASE REPORT A 53-year-old woman with a 5-year history of MF visited our hospital. Her disease had progressed to tumour-stage (T3N0M0, stage IIB) despite multiple treatments, in- SHORT COMMUNICATION cluding psoralen plus ultraviolet-A phototherapy, local radiation, total-body electron-beam radiation, vorinostat and etoposide. Serum KL-6 (Krebs von den Lungen-6, a biomarker of interstitial pneumonia) was measured prior to administration of intravenous interferon (IFN)-γ, which occasionally leads to interstitial pneumonia. KL-6 is an epitope located in the N-terminal domain of MUC1. Her serum level was high, 1,171 U/ml (normal range 105–435 U/ml) (Fig. 1A, B); however, computed tomo- graphy (CT) showed no significant findings in her lungs, except radiation pneumonitis in the right lung (Fig. 1C). She was treated with IFN-γ (Day 0), followed by mo- gamulizumab and gemcitabine. Despite these treatments, new lesions appeared in the lymph nodes and spleen on day 143 (T3NXM1, stage IVB). Her serum KL-6 level increased to 9,650 U/ml as the disease progressed on day 146. After 5 courses of CHOP (a combination therapy of cyclophospha- mide, doxorubicin, vincristine and prednisolone), serum levels of soluble interleukin-2 receptor (sIL-2R) and KL-6 decreased, together with clinical improvement in lymphoma lesions on day 238. Both KL-6 and sIL-2R re- flected the patient’s clinical condition. Interstitial pneumonia did not occur during the course of treatment (Fig. 1C). She underwent allogeneic bone marrow transplantation. However, her skin lesions worsened 14 days after the transplantation. Skin biopsy showed CD4-positive lym­phoma cell infiltration in both the epidermis and dermis when the patient was Stage IIB. MUC1 positive cells were sparse in those lymphoma cells by immunohistochemical staining using a KL-6 antibody (Fig. 2A–C). The relapsed lesions exhibited a dense Fig. 1. Clinical characteristics and KL-6/sIL2R time course. (A) Clinical findings of skin lesions. Day 0: initiation date of intravenous interferon (IFN)-γ. (B) Krebs von den Lungen-6 (KL-6) and sIL-2R levels. The patient was treated with: (i) recombinant IFN-γ, followed by: (ii) mogamulizumab; (iii) gemcitabine; (iv) a combination of cyclophosphamide, doxorubicin, vincristine and prednisolone; and (v) bone marrow transplantation. (C) Computed tomography did not reveal any significant alterations, except for radiation pneumonitis in the right lung. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2017 Acta Dermato-Venereologica. doi: 10.2340/00015555-2638 Acta Derm Venereol 2017; 97: 747–748