Ezenekwe Amobi M, Collins Brian T, Ponder T Brent
Department of Pathology, Saint Louis University School of Medicine, Missouri, USA.
Acta Cytol. 2005 Sep-Oct;49(5):549-53. doi: 10.1159/000326204.
Mixed giant cell tumor (MGCT) of the pancreas is a rare malignant neoplasm. The tumor contains pleomorphic giant cells (PGC), pleomorphic mononuclear cells (PMC) and osteoclastic giant cells (OGC). We describe the first fine needle aspiration biopsy (FNAB) diagnosis of this tumor.
A 76-year-old woman was discovered (on imaging studies) to have an apparently inoperable mass in the head of the pancreas. Computed tomography-guided FNAB showed a malignant neoplasm with features of an MGCT. PGC/PMC, OGC and spindle cells were present. The PGC/PMC expressed epithelial antigens, pancytokeratin, CAM 5.2, AE1/AE3 and epithelial membrane antigen (EMA). The spindle cells focally stained for EMA. OGC were negative for the epithelial antigens. OGC, PGC/PMC and the spindle cells were positive for the mesenchymal marker vimentin.
FNAB was instrumental in making the diagnosis of a rare pancreatic tumor, MGCT. Immunocytochemistry was helpful in making a definitive diagnosis and suggested that MGCT is a carcinosarcoma like neoplasm. The morphology and immunocytochemical profile raise the possibility that osteoclastic giant cell tumor and pleomorphic giant cell tumor may be different morphologic and biologic expressions of the same tumor.
胰腺混合性巨细胞瘤（MGCT）是一种罕见的恶性肿瘤。该肿瘤包含多形性巨细胞（PGC）、多形性单核细胞（PMC）和破骨细胞样巨细胞（OGC）。我们描述了首例经细针穿刺活检（FNAB）诊断的该肿瘤病例。
一名76岁女性（经影像学检查）被发现胰腺头部有一个明显无法手术切除的肿块。计算机断层扫描引导下的FNAB显示为具有MGCT特征的恶性肿瘤。存在PGC/PMC、OGC和梭形细胞。PGC/PMC表达上皮抗原、全细胞角蛋白、CAM 5.2、AE1/AE3和上皮膜抗原（EMA）。梭形细胞局部EMA染色阳性。OGC上皮抗原呈阴性。OGC、PGC/PMC和梭形细胞间充质标志物波形蛋白呈阳性。
FNAB有助于诊断罕见的胰腺肿瘤MGCT。免疫细胞化学有助于做出明确诊断，并提示MGCT是一种类似癌肉瘤的肿瘤。其形态学和免疫细胞化学特征提示破骨细胞样巨细胞瘤和多形性巨细胞瘤可能是同一肿瘤的不同形态学和生物学表现形式。
