Seifert G, Donath K, Schäfer R
Institute of Pathology, University of Hamburg, Germany.
Pathol Res Pract. 1999;195(4):247-52. doi: 10.1016/S0344-0338(99)80042-9.
Lipomatous pleomorphic adenoma is an unusual subtype with a lipomatous stromal component of more than 90% of the tumour tissue. This special type of pleomorphic adenoma must be distinguished from other types of lipomatous tumours or non-tumourous lipomatosis of the salivary glands. Until now only two cases of lipomatous pleomorphic adenoma have been reported in the literature. We report of a 36-year old woman who developed a well circumscribed nodule measuring 3.5 x 2.5 x 2 cm in the right parotid gland. The cut surface was grey-yellowish. Histologically, more than 90% of the tumour tissue was fatty tissue with univacuolar adipocytes. The pleomorphic epithelial elements were duct-like cells forming small lumina and spindle-shaped myoepithelial cell with surrounding mucoid stroma. Components of pleomorphic adenoma were intermingled with mature adipose tissue which was more concentrated in the central portion of the adenoma. Some compressed epithelial cords in the adipose tissue formed a septa-like pattern. The differential diagnosis to other lipomatous tumours (lipoadenoma, lipoma) and to non-tumourous interstitial lipomatosis as well as the possible pathogenesis as metaplastic change or epithelial-mesenchymal transdifferentiation are discussed.
脂肪型多形性腺瘤是一种不常见的亚型，其脂肪性间质成分占肿瘤组织的90%以上。这种特殊类型的多形性腺瘤必须与其他类型的脂肪性肿瘤或涎腺非肿瘤性脂肪瘤病相鉴别。迄今为止，文献中仅报道过两例脂肪型多形性腺瘤。我们报告一例36岁女性，其右侧腮腺出现一个边界清晰的结节，大小为3.5×2.5×2厘米。切面呈灰黄色。组织学检查显示，超过90%的肿瘤组织为含单泡脂肪细胞的脂肪组织。多形性上皮成分是形成小腔隙的导管样细胞和梭形肌上皮细胞，周围有黏液样间质。多形性腺瘤的成分与成熟脂肪组织相互交织，脂肪组织在腺瘤中央部分更为集中。脂肪组织中一些受压的上皮条索形成类似间隔的形态。文中讨论了与其他脂肪性肿瘤（脂肪腺瘤、脂肪瘤）及非肿瘤性间质脂肪瘤病的鉴别诊断，以及作为化生改变或上皮-间充质转分化的可能发病机制。
