SPLITTERS VS LUMPERS

The distinction between splitters and lumpers has not been very significant until now, with advantages and disadvantages on either side. Currently it is difficult to be a lumper in medicine. Expressions like "personalized medicine", or "every tumor is different" are heard every day. Pathologists should be at the forefront of this movement, I have always said that we will move a lot faster if we classify the tumors by trying to separate them when there are different histologic features as these morphologic differences are most probably the reflection of molecular differences. Classical examples of this issue in ovarian epithelial tumors are transitional cell carcinoma, and microcystic carcinoma. Regardless of their behavior, or immunoreactivity, or the focal presence of serous carcinoma, they should be separated just because they are different. I am sure that molecular studies will show differences that may change prognosis or treatment. Having them together with serous, or not even mentioning them, like in the case of microcystic carcinoma, will delay any progress. We have learned that there are different types of leiomyomas of the uterus, and this can be significant. We should learn from hematopathology or renal oncologic pathology, because these distinctions among the different tumors are becoming important for patient care. The tumors are telling us " we are different" and we are saying no, you are not because there is a focal area of serous carcinoma, or p53 is positive in both areas.

Lumping diagnosis for the sake of uniformity is not a very good way of making progress in gynecologic oncology.