软组织多形性玻璃样变血管扩张性肿瘤的临床病理学观察

Pleomorphic hyalinizing angiectatic tumor of soft parts:a clinicopathological study of six cases

目的探讨软组织多形性玻璃样变血管扩张性肿瘤（pleomorphic hyalinizing angiectatic tumor of soft parts,PHAT）的临床病理特点。方法回顾性分析6例PHAT的临床资料、组织学形态和免疫组化标记,并复习相关文献。结果6例均发生于成年人,男性和女性各占3例,平均年龄为44岁。肿瘤分别位于下肢（3例）、颈部（2例）和腹膜后（1例）。临床上多表现为无痛性肿块,术前病程为3个月-38年。大体上,肿瘤境界清楚,结节状,平均直径为4.3 cm。切面呈灰白、灰红或灰褐色,部分病例可见出血性囊腔。镜下,肿瘤内含有成簇分布的薄壁扩张血管,血管壁附有一层厚的玻璃样变物质（纤维素和胶原纤维）,可向血管周围间质内延伸,血管之间为片状分布的多形性瘤细胞,核大深染,核内可见假包涵体,但核分裂象罕见。部分区域内瘤细胞呈梭形,排列成条束状,类似神经鞘瘤。免疫组化标记显示,瘤细胞主要表达vimentin,部分病例还表达CD34和CD99,而S-100蛋白、α-SMA、bcl-2、EMA和CD68均为阴性。6例均经手术切除,随访8个月-13年,无1例复发。结论PHAT是一种具有低度恶性潜能的软组织肿瘤，熟悉其形态学特征有助于诊断和鉴别诊断。临床上对PHAT宜采取完整性切除，并注意随访。

Purpose To study the clinicopathological characteristics of pleomorphic hyalinizing angiectatic tumor of soft parts （PHAT）. Methods The clinical, pathoglogical and immunohistochemical features of six cases of PHAT were analyzed. The literature was reviewed. Results All cases occurred in adults with an equal gender distribution. The average age was 44 years （ range 24 - 64 yrs）. The tumors were located in the lower extremities （ n = 3 ） , neck （ n = 2 ）, and retroperitoneum （ n = 1 ）. The main clinical presentation was a painless mass with duration ranging from 3 months to 38 years. Grossly, the tumors were well circumscribed, measuring 4. 3 cm in mean diameter. They showed grayish, gray to tan color on cut surface. In 2 cases, hemorrhagic cysts of varying size were noted. Microscopically, the tumor was characterized by clusters of thin-walled ectatic vessels lined by thick hyalinizing fibrin-collagen material,with sheetlike or fascicular proliferation of spindled to pleomorphic cells between or around the vessels. Mitotic figures were rare, however, nuclear pseudoinclusions were prominent. Immunohistechemically, the neoplastic cells were positive for vimentin, with partial expression of CD34 and CD99, but negative for S-100 protein, desmin, α-SMA and CD31. MIB-1 proliferative activity was lower than 2%. Follow-up data showed no recurrence after complete excision in all 6 cases. Conclusions PHAT is a rare soft tissue neoplasm with low grade malignant potential. Recognizing its characteristic features will facilitate the diagnosis and differential diagnosis. Complete resection with negative margins remains the mainstay of treatment. Long-term surveillance is required.