子宫奇异型平滑肌瘤的临床病理分析

目的探讨子宫奇异型平滑肌瘤组织形态、免疫组织化学及生物学行为特征.方法对25例子宫奇异型平滑肌瘤进行瘤体大体及镜下观察;20例行平滑肌肌动蛋白(SMA)、增殖细胞核抗原(PCNA)、雌激素受体(ER)、孕激素受体(PR)免疫组织化学SP和ABC法染色,20例子宫富于细胞性平滑肌瘤作为对照组;并行临床资料分析及跟踪随访.结果临床主要表现为阴道不规则出血、腹痛和盆腔包块,1例合并大量腹水,2例合并妊娠,无应用孕酮类药物者.镜下部分或全部胞核奇异,双核或多核易见,核内多见1至数个较大红染包涵体样物(直径7～26 μm),核分裂象0～2/10高倍视野(HPF).20例奇异型平滑肌瘤做 SMA染色,全部奇异瘤细胞胞质呈肌源性表达,与对照组相同;PCNA染色,观察组15例(75.0%)呈弱阳性,与对照组相比,差异有显著意义(P=0.027);在观察组中18例(90.0%)ER呈阴性表达,表现有ER丢失现象,对照组则全部阳性,两组相比差异有极显著性意义,P＜0.005;PR两组均呈阳性;同时发现大部分核内包涵体样物呈肌源性表达,即SMA阳性.长期随访无复发.结论子宫奇异型平滑肌瘤虽形态奇异,但属良性肿瘤.本组形态学变化与外源性孕酮药物无关,与妊娠关系应予以关注.免疫组织化学表达有一定特征,应与平滑肌肉瘤及恶性潜能待定平滑肌瘤进行鉴别.

A clinicopathological study of bizarre leiomyoma

OBJECTIVE: To investigate the feature of histomorphology and biology of uterine bizarre leiomyoma from the clinical, pathological features as well as the immunohistochemical expression. METHODS: Totally 25 cases of leiomyomas were studied. Among them, immuno-histochemical staining (SP and ABC methods) for smooth muscle actin (SMA), proliferative cell nucleus antigen (PCNA), estrogen receptors (ER), and progesterone receptors (PR) were performed in 20 cases. The clinical features and follow-up records were analyzed. RESULTS: The main clinical findings were irregular vaginal bleeding, pain and pelvic tumor. One case was with immense amount of ascitis and the other two were with pregnancy. All the cases had no history of taking pregestine. Light microscopy showed that part of all the cell nuclei were bizarre, accompanying with double or multiple nuclei in which rather big and reddish staining inclusion bodies were obtained (D = 7 - 26 micro m), and the mitotic figures were 0 - 2/10 HPF. Among 20 cases with immunohistochemical staining, markers indicating muscle cells in origin were positive in the bizarre cells, 15 of which (75%) with negative or weak positive PCNA, and 18 of which (90%) with negative ER. There were significant difference between the studied and control groups (P = 0.027, P < 0.005 respectively) and in addition, PR was positive in both these two groups. A majority of the nucleus inclusion bodies was SMA positive. Follow-up records demonstrated so far no recurrence cases obtained. CONCLUSIONS: Uterine atypical leiomyoma belongs to benign tumor, although its shape is bizarre. In this group, the morphology changes are correlated with pregnancy, but not with pregestine. The expression of immunohistochemistry shows certain features, and is important to identify uterine bizarre leiomyoma with leiomyosarcoma and STUMP in pathological diagnosis.