Goodlad J R, Mentzel T, Fletcher C D
Department of Histopathology, St Thomas's Hospital, London, UK.
Histopathology. 1995 Mar;26(3):229-37. doi: 10.1111/j.1365-2559.1995.tb01436.x.
Low grade fibromyxoid sarcoma is a recently recognized, uncommon soft tissue neoplasm with a tendency to develop in deep soft tissue of young adults. Diagnostic criteria have not been well defined and this tumour has not been widely accepted as a distinct entity. Eleven new cases are reported here for which reproducible histological features are described and in which the immunohistochemical profile of the tumour cells is documented for the first time. Ten of the eleven patients were male and the majority were young or middle-aged adults (median age 45 years). All except one of the tumours were situated in deep soft tissue. Lower limb (four cases) and chest wall (three cases) were the commonest primary sites; one case each arose in the groin, buttock, axilla and retroperitoneum. Follow-up (median duration 6 years) was available in nine patients. Six developed local recurrence and in five cases recurrences were multiple. Pulmonary metastasis occurred in one patient. All tumours were characterized by the presence of bland spindle cells, showing a mainly whorled or focally linear arrangement, set in alternating areas with a fibrous or myxoid stroma. Tumour cells were small, spindle to stellate, with poorly defined, palely eosinophilic cytoplasm and hyperchromatic ovoid nuclei. Most tumour cells showed strong staining with antibodies to vimentin, while occasional cells stained positively for actin, desmin and cytokeratin, in keeping with focal myofibroblastic differentiation. Ultrastructural examination in one case revealed features of fibroblasts. Careful consideration of the morphological and immunohistochemical features of these tumours permits a positive diagnosis of low grade fibromyxoid sarcoma and allows its distinction from a number of other benign and malignant soft tissue neoplasms.
低度恶性纤维黏液样肉瘤是一种最近才被认识的、不常见的软组织肿瘤，倾向于在年轻成年人的深部软组织中发生。其诊断标准尚未明确界定，并且该肿瘤尚未被广泛接受为一种独立的实体。本文报告了11例新病例，描述了其可重复的组织学特征，并首次记录了肿瘤细胞的免疫组化谱。11例患者中有10例为男性，大多数为年轻或中年成年人（中位年龄45岁）。除1例肿瘤外，所有肿瘤均位于深部软组织。下肢（4例）和胸壁（3例）是最常见的原发部位；腹股沟、臀部、腋窝和腹膜后各有1例。9例患者有随访资料（中位随访时间6年）。6例出现局部复发，其中5例为多次复发。1例患者发生肺转移。所有肿瘤的特征是存在温和的梭形细胞，主要呈漩涡状或局灶性线性排列，与纤维或黏液样间质交替出现。肿瘤细胞小，呈梭形至星状，胞质界限不清、淡嗜酸性，核呈深染的卵圆形。大多数肿瘤细胞对波形蛋白抗体呈强阳性染色，而偶尔有细胞对肌动蛋白、结蛋白和细胞角蛋白呈阳性染色，符合局灶性肌成纤维细胞分化。1例患者的超微结构检查显示有成纤维细胞特征。仔细考虑这些肿瘤的形态学和免疫组化特征有助于对低度恶性纤维黏液样肉瘤做出肯定诊断，并使其与其他一些良性和恶性软组织肿瘤相鉴别。
