Sanada Yuichi, Yoshida Kazuhiro, Itoh Masaoki, Okita Riki, Okada Morihito
Department of Surgical Oncology, Research Institution for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
Hepatobiliary Pancreat Dis Int. 2009 Feb;8(1):97-102.
Invasive pancreatic carcinoma generally appears as poorly defined mass reflecting the infiltrative growth. We aimed to identify the histological and immunohistochemical features in a rare case of pancreatic carcinoma showing exophytic growth.
A 67-year-old woman presented with a mass of 5.0 cm in diameter in the pancreatic head. Preoperative computed tomography revealed a well-demarcated, primarily solid mass with a central low-density area. Magnetic resonance cholangiopancreatography revealed neither encasement nor dilation of the main pancreatic duct. An incorrect preoperative diagnosis was made of solid pseudopapillary tumor of the pancreas. Elevated serum carcinoembryonic antigen (CEA) levels and abnormal FDG positron emmission tomography accumulation suggested that the tumor had malignant potential requiring a pancreatoduodenectomy.
The head of the pancreas contained a well-circumscribed encapsulated mass of 5.0 cm in diameter, comprising 50% adenocarcinoma, with mucinous carcinoma in the center and anaplastic carcinoma at the periphery. The anaplastic carcinoma comprised pleomorphic cells (PCs) and pleomorphic giant cells (PGCs). The PGCs phagocytozed mononuclear PCs and lymphocytes adjacent to the capsule without infiltrating the capsule itself. Immunohistochemistry revealed that the anaplastic carcinoma cells including PGCs were positive for the tumor antigen Mucin 1 and CEA but negative for vimentin.
Our observations suggest anaplastic carcinoma components in the present tumor have a ductal origin and that the exophytic tumor growth is associated with the phagocytotic activity of PGCs.
浸润性胰腺癌通常表现为边界不清的肿块，反映其浸润性生长。我们旨在确定一例罕见的呈外生性生长的胰腺癌的组织学和免疫组化特征。
一名67岁女性，胰头部有一直径5.0 cm的肿块。术前计算机断层扫描显示一个边界清楚、主要为实性的肿块，中央有低密度区。磁共振胰胆管造影显示主胰管未被包绕也无扩张。术前误诊为胰腺实性假乳头状瘤。血清癌胚抗原（CEA）水平升高及异常的氟脱氧葡萄糖正电子发射断层扫描显像提示该肿瘤具有恶性潜能，需行胰十二指肠切除术。
胰头部有一个直径5.0 cm、边界清楚的包膜完整肿块，其中50%为腺癌，中央为黏液癌，周边为间变性癌。间变性癌由多形性细胞（PCs）和多形性巨细胞（PGCs）组成。PGCs吞噬包膜附近的单核PCs和淋巴细胞，但未浸润包膜本身。免疫组化显示包括PGCs在内的间变性癌细胞肿瘤抗原Mucin 1和CEA阳性，波形蛋白阴性。
我们的观察结果提示，本肿瘤中间变性癌成分起源于导管，外生性肿瘤生长与PGCs的吞噬活性有关。
