Siebert J D, Williams R P, Pulitzer D R
Department of Pathology, University of Texas Health Science Center, San Antonio 78284-7750, USA.
Mod Pathol. 1996 Mar;9(3):249-52.
Common histologic variants of liposarcoma are readily recognized. Histologic classification might be difficult, however, when liposarcoma demonstrates cartilaginous differentiation. Although this phenomenon has previously been noted, it has not, to our knowledge, been reported as a specific pathologic entity. All three patients in the present study were men, ages 37, 42, and 63 years. Each presented with a solitary, enlarging mass of the thigh that was surgically excised. The tumors ranged in size from 8 to 13 cm. Microscopically, each lesion displayed characteristic features of myxoid liposarcoma; in addition, all possessed discrete, rounded foci of mature-appearing hyaline cartilage. One case displayed small foci showing chondrocyte atypia. No other patterns of mesenchymal differentiation were present. All patients received postoperative radiation therapy. No recurrences or metastases have been identified (mean duration, 39 mo). Myxoid liposarcomas with cartilaginous differentiation are of importance because they might be misdiagnosed as malignant mesenchymoma. The latter, if not qualified as to histologic grade, might be presumed to be a biologically more aggressive lesion. In addition, these lesions must be distinguished from two benign processes: chondroid lipoma and extraskeletal chondroma with lipoblast-like cells. Additional studies of this uncommon variant of liposarcoma will be necessary to document further its status as a low-grade sarcoma.
脂肪肉瘤常见的组织学变异型很容易识别。然而，当脂肪肉瘤表现出软骨分化时，组织学分类可能会有困难。虽然这种现象以前曾被注意到，但据我们所知，尚未作为一种特定的病理实体报道过。本研究中的三名患者均为男性，年龄分别为37岁、42岁和63岁。每位患者均表现为大腿部孤立性、进行性增大的肿块，均接受了手术切除。肿瘤大小在8至13厘米之间。显微镜下，每个病变均显示出黏液样脂肪肉瘤的特征性表现；此外，所有病变均有离散的、圆形的成熟透明软骨灶。1例显示有小灶性软骨细胞异型性。未发现其他间充质分化模式。所有患者均接受了术后放疗。未发现复发或转移（平均病程39个月）。具有软骨分化的黏液样脂肪肉瘤很重要，因为它们可能被误诊为恶性间叶瘤。后者如果未明确组织学分级，可能会被认为是生物学行为更具侵袭性的病变。此外，这些病变必须与两种良性病变相鉴别：软骨样脂肪瘤和具有脂肪母细胞样细胞的骨外软骨瘤。有必要对这种不常见的脂肪肉瘤变异型进行进一步研究，以进一步证明其作为低级别肉瘤的地位。
