Gynecological Issues Identified By Pathology Review
Gynecological Issues Identified By Pathology Review
According to WHO, a mixed carcinoma should only be diagnosed when the minor component makes up at least 10% of the neoplasm. However, I would recommend that all morphological subtypes within an ovarian carcinoma be documented and the percentages listed, even if the minor component accounts for less than 10%. One point I wish to make is that true mixed carcinomas of the ovary (unlike in the uterus) are relatively uncommon, although they do occur, and there is a tendency to overdiagnose these. A combination of endometrioid and clear cell carcinoma occasionally occurs as both tumour types commonly arise in endometriosis. Neoplasms that are diagnosed as mixed serous and endometrioid or mixed serous and clear cell carcinoma mostly represent high grade serous carcinomas with areas that mimic endometrioid or clear cell carcinoma (figure 7); the combination of serous and endometrioid or serous and clear cell carcinoma is uncommon. WT1 may be useful in this regard as serous carcinomas of the ovary are usually diffusely positive while most endometrioid and clear cell carcinomas are negative. The combinations of serous and undifferentiated or endometrioid and undifferentiated carcinoma sometimes occur. The former should be reported as a high grade serous carcinoma with a comment that undifferentiated areas are present and that these are in keeping with the extreme end of the spectrum of high grade serous carcinoma. As in the uterus, the combination of endometrioid and undifferentiated carcinoma occasionally occurs (discussed in detail later) and this probably represents dedifferentiation within a low grade endometrioid adenocarcinoma (dedifferentiated endometrioid adenocarcinoma).
(Enlarge Image)
Figure 7.
High grade ovarian serous carcinoma with clear cells; the clear cell areas may result in misdiagnosis as a clear cell carcinoma or mixed carcinoma with a clear cell component.
Mixed Carcinomas of the Ovary
According to WHO, a mixed carcinoma should only be diagnosed when the minor component makes up at least 10% of the neoplasm. However, I would recommend that all morphological subtypes within an ovarian carcinoma be documented and the percentages listed, even if the minor component accounts for less than 10%. One point I wish to make is that true mixed carcinomas of the ovary (unlike in the uterus) are relatively uncommon, although they do occur, and there is a tendency to overdiagnose these. A combination of endometrioid and clear cell carcinoma occasionally occurs as both tumour types commonly arise in endometriosis. Neoplasms that are diagnosed as mixed serous and endometrioid or mixed serous and clear cell carcinoma mostly represent high grade serous carcinomas with areas that mimic endometrioid or clear cell carcinoma (figure 7); the combination of serous and endometrioid or serous and clear cell carcinoma is uncommon. WT1 may be useful in this regard as serous carcinomas of the ovary are usually diffusely positive while most endometrioid and clear cell carcinomas are negative. The combinations of serous and undifferentiated or endometrioid and undifferentiated carcinoma sometimes occur. The former should be reported as a high grade serous carcinoma with a comment that undifferentiated areas are present and that these are in keeping with the extreme end of the spectrum of high grade serous carcinoma. As in the uterus, the combination of endometrioid and undifferentiated carcinoma occasionally occurs (discussed in detail later) and this probably represents dedifferentiation within a low grade endometrioid adenocarcinoma (dedifferentiated endometrioid adenocarcinoma).
(Enlarge Image)
Figure 7.
High grade ovarian serous carcinoma with clear cells; the clear cell areas may result in misdiagnosis as a clear cell carcinoma or mixed carcinoma with a clear cell component.
