The Differential Diagnosis And Two-dimensional Electropheresis Analysis Of Uterine Smooth Muscle Tumors

To explore more sensitive and specific immunohistochemical markers in the differential diagnosis of uterine leiomyosarcoma (ULMS) and unusual leiomyomas. Methods:Formalin-fixed paraffin-embedded tissue blocks were selected from 82 patients with smooth muscle tumors of the uterus, including 17 patients with leiomyosarcoma (LMS), 25 with cellular leiomyoma (CL), 15 with bizarre leiomyoma (BL) and 25 with ordinary leiomyoma (OL). The routine streptavidin-peroxidase (SP) immunohistochemical technique was used to examine the expression of desmin, a smooth muscle actin (SMA), calponin h1, h-caldesmon, estrogen receptor (ER), progesterone receptor (PR), proliferating cell nuclear antigen (PCNA), mast cells, and CD44v3 in serial sections of each tumor. Results:The expression rates of desmin, SMA, h-caldesmon and CD44v3 in uterine LMS were all lower than those in CL and BL (all P <0.05), but these markers had limited significance in differentiation of ULMS from CLor BL. Compared to those in CL or BL, the expression rates of ER and PR and the number of mast cells were significantly lower in LMS (all P <0.01), while the expression of PCNA in LMS was higher (P <0.01) . When using the cut-off value of less than 5 mast cells per HPF to distinguish LMS from CL and BL, the sensitivity and specificity of this cut-off value were 100% and 92.5% respectively. Conclusions:Because the estimation of mitotic count was subject to significant variation, combination the immunohistochemical expression of ER and PR with proliferating cell nuclear antigen index and mast cells count seemed to be helpful for the discrimination of unusual leiomyomas from leiomyosarcoma. The number of mast cells was helpful in differential diagnosis of ULMS with high sensitivity and specificity.