Uterine leiomyosarcoma arising in leiomyoma: clinicopathological study of four cases and literature review.

In this study we examined four cases of leiomyosarcoma (LMS) arising in leiomyoma (LM). The patients ranged from 40 to 64 years old. Symptoms were unspecific and preoperative diagnosis of LMS had not been made. Size of the tumors ranged from 4 cm to 20.5 cm. All patients were in stage I and no patients developed recurrent disease. Histologically, the LMS component showed moderate to severe cytological atypia and an increased mitotic count in all cases. Tumor cell necrosis in the LMS was seen in three cases. Associated LM component was cellular in one case. The LMS component showed p53 expression in three of four cases and p16 expression was seen in two cases. The LM component lacked p53 expression in all cases and demonstrated p16 expression in two cases, including one case of cellular LM. In all cases, Ki-67-positive cells were less than 5% in the LM component and more than 25-30% in the LMS component. This study reveals that: (i) malignant transformation can occur even in relatively small LM; (ii) patients with LMS with an LM component have a favorable prognosis; and (iii) immunohistochemical examination of p53, p16 and Ki-67 is useful for identification of malignant focus.

Immunohistochemistry of p63 in primary and secondary vulvar Paget's disease.

Vulvar Paget's disease (VPD) is classified into primary and secondary types. Differentiation of these subsets in biopsy specimen is important for appropriate therapy. Expression profile of cytokeratin (CK) 7 and CK20, gross cystic disease fluid protein-15 and uroplakin III has been reported as a differentiation marker of primary and secondary VPD. To examine the role of p63 immunostaining in differential diagnosis between primary VPD and VPD secondary to urothelial carcinoma (VPD-UC), expression of p63 was examined in nine cases of VPD. Paget cells in seven cases of VPD without UC did not express p63. In two cases of VPD associated with UC, Paget cells and UC cells had identical CK expression profile. UC cells were positive for p63 in both cases. In one case, Paget cells were positive for p63 and examination of the resected specimen showed that VPD was secondary to UC. In another case, Paget cells were negative for p63 and this was diagnosed as primary VPD independent of UC. This indicates that p63 is absent in Paget cells in primary VPD and is therefore useful in differentiating primary VPD from VPD-UC.