Serous tumors of low malignant potential of the ovary-molecular pathology:part 2

A progressive development from serous tumors of low malignant potential (SL MP) to bluntly invasive serous carcinoma has been suggested in parallel to the concept of adenoma-carcinoma sequence in colorectal carcinomas. However , recent genetic data enforces a reassessment of the concept that SLMP tumo rs represent precursor lesions to invasive serous carcinoma. Despite the be nign nature of the majority of these tumors, some will behave worse. The id entification of those SLMP tumors with an aggressive clinical behavior rema ins difficult, regardless of a growing body of molecular pathologic investi gations. Expression of p53, c-erbB2, as well as the presence of ras mutatio ns are not helpful in this respect. Immunostaining of both MMP-2 and baseme nt membrane components such as collagen type IV, as well as the disintegrat ion of collagen type I at the tumor-host inter-face, may be helpful for the diagnosis of a microinvasive SLMP, but it remains questionable whether thi s is important for prognosis. The differential diagnosis to frankly invasiv e carcinoma depends on the detection of destructive stromal invasion. In qu estionable cases, the loss of N-cadherin would argue for the presence of a carcinoma whereas the coexpression of p21 and MDM2 is rather characteristic for SLMP tumors.