Khan Z M, Cockerell C J
Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, USA.
Am J Dermatopathol. 1997 Apr;19(2):174-9. doi: 10.1097/00000372-199704000-00012.
Atypical fibroxanthoma is a malignant fibrohistiocytic neoplasm that develops most commonly on sun-exposed skin of elderly individuals. A number of different variants have been described, ranging from a purely spindle cell type to a xanthomatous form. We recently observed an unusual variant of atypical fibroxanthoma in which there were numerous osteoclast-like multinucleated giant cells. Histologically, there was a diffuse spindle cell neoplasm in the dermis exhibiting fibrohistiocytic differentiation associated with inflammatory cells. The neoplastic spindle cells were markedly pleomorphic and many were in mitosis, some being tripolar and tetrapolar. In addition to these features, which are common in atypical fibroxanthoma, there were numerous multinucleated giant cells scattered throughout the lesion with features resembling normal osteoclasts. Epithelioid cells with features of histiocytes were seen in association with these cells. No osteoid was observed, however, that suggested monocyte-macrophage differentiation. The histologic appearance of this lesion was reminiscent of the giant cell variant of malignant fibrous histiocytoma, also termed malignant giant cell tumor of soft parts. Thus, osteoclast-like giant cells may be seen in atypical fibroxanthoma. These cells probably represent multinucleated histiocytes rather than true osteoclasts. It is important to recognize this variant to avoid confusion with other malignant soft tissue neoplasms.
非典型纤维黄色瘤是一种恶性纤维组织细胞瘤，最常发生于老年人暴露于阳光下的皮肤。已描述了许多不同的变体，从纯粹的梭形细胞类型到黄色瘤样形式。我们最近观察到一种非典型纤维黄色瘤的不寻常变体，其中有许多破骨细胞样多核巨细胞。组织学上，真皮内有弥漫性梭形细胞肿瘤，表现出与炎症细胞相关的纤维组织细胞分化。肿瘤性梭形细胞明显多形性，许多处于有丝分裂状态，有些为三极和四极。除了这些非典型纤维黄色瘤常见的特征外，整个病变中还散在着许多多核巨细胞，其特征类似于正常破骨细胞。可见具有组织细胞特征的上皮样细胞与这些细胞相关。然而，未观察到类骨质，提示单核细胞-巨噬细胞分化。该病变的组织学表现让人联想到恶性纤维组织细胞瘤的巨细胞变体，也称为软组织恶性巨细胞瘤。因此，非典型纤维黄色瘤中可能会出现破骨细胞样巨细胞。这些细胞可能代表多核组织细胞而非真正的破骨细胞。认识到这种变体很重要，以避免与其他恶性软组织肿瘤混淆。
