Lee Mi-Woo, Nam Soon-Yuhl, Choi Hye-Jin, Choi Jee-Ho, Moon Kee-Chan, Koh Jai-Kyoung
Department of Dermatology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul 138-736, South Korea.
J Cutan Pathol. 2005 Mar;32(3):240-4. doi: 10.1111/j.0303-6987.2005.00293.x.
Myoepithelioma is a rare but well-characterized group of tumours, among which myoepithelioma of the salivary glands is the best known. We report two patients with myoepithelioma of parotid gland presenting as infra-auricular subcutaneous mass. The lesions were clinically suspected to be epidermal cyst. The biopsies revealed that most of the tumour cells showed epithelioid features with oval or spindle eosinophilic cytoplasm. No ductal or syringomatous epithelial structures were observed. The tumour cells showed cytoplasmic immunoexpressions of vimentin, cytokeratin (AE1/AE3), S-100 protein and smooth muscle actin (SMA). In one patient, a strong calponin positivity was observed. Maguetic resonance imaging (MRI) of both patients revealed exophytic, well-defined, strongly enhancing mass in superficial lobe of parotid gland, confirming the parotid gland origin. Myoepithelioma of parotid gland can be presented as a slowly growing tumour of pre- or infra-auricular area. In dermatologic department, it can be misdiagnosed as various dermal or subcutaneous tumours.
肌上皮瘤是一组罕见但特征明确的肿瘤，其中涎腺肌上皮瘤最为人熟知。我们报告了2例表现为耳下皮下肿块的腮腺肌上皮瘤患者。这些病变临床上怀疑为表皮样囊肿。活检显示，大多数肿瘤细胞呈上皮样特征，具有椭圆形或梭形嗜酸性细胞质。未观察到导管或汗腺样上皮结构。肿瘤细胞显示波形蛋白、细胞角蛋白（AE1/AE3）、S-100蛋白和平滑肌肌动蛋白（SMA）的细胞质免疫表达。在1例患者中，观察到钙调蛋白呈强阳性。两名患者的磁共振成像（MRI）均显示腮腺浅叶有外生性、边界清晰、强化明显的肿块，证实了肿瘤起源于腮腺。腮腺肌上皮瘤可表现为耳前或耳下区域缓慢生长的肿瘤。在皮肤科，它可能被误诊为各种皮肤或皮下肿瘤。
