Making it clear: a review of the MR imaging features of clear cell carcinoma of the ovary
Type:Scientific Electronic Presentation
Authors: Miguel Braga, Teresa Margarida Cunha
Keywords:clear cell carcioma of the ovary

Ovarian tumours are divided based on histopathologic features with epithelial surface cell tumours being the most common. Specific subtypes include serous (the most common), mucinous, seromucinous, endometrioid, clear cell, Brenner, and undifferentiated [1].


The radiologist plays an important role in the diagnosis of ovarian tumours, namely in suggesting ovarian origin, predicting benign, borderline and malignant subtypes, and evaluating the extent of disease.


Imaging findings of ovarian tumours are often nonspecific, however, some subtypes have distinguishing features [2]. Differentiating these subtypes based on their characteristics can guide patient management and aid the pathologist in establishing the diagnosis.


Thus, the objective of this study was to retrospectively assess the imaging characteristics of clear... more

Material and methods

From January 2003 to August 2021, 18 patients with histopathologically proven clear cell carcinoma of the ovary on surgical specimen were found in our hospital's electronic medical charts. Of these patients, 8 were excluded because they did not undergo preoperative MRI. Thus, 10 patients were included in this study, with a mean age of 60,2 years (age range 47-92 years).

Pathological diagnosis
All tumours were surgically removed and the diagnosis was confirmed based on our institute's pathology report. Information regarding endometriosis or clear cell adenofibroma was collected.

Clinical information
Clinical data including history of thrombosis and the serum levels of calcium and CA 125 were collected by retrospective review of the medical records. Hypercalcemia was indicated by the presence of serum... more


Clear cell carcinoma presented as a unilateral tumour in 90% of the patients (9/10), 56% (5/9) on the left side and 44% (4/9) on the right side. Only one patient presented with a bilateral tumour.

Of the ten patients, clear cell carcinoma presented as a cystic tumour with mural nodules in 60% of the cases (6/10), whether unilocular [66% (4/6)] (figure 1) or multilocular [33% (2/6)] (figure 2). Less frequently, the tumours were mixed cystic and solid [30% (3/10)] or solid [10% (1/10)].

Signal intensity of the solid component
Regarding the patients with cystic and mixed cystic and solid tumours, the solid component presented with intermediate signal intensity on T2-WI in 89% of the cases (8/9). Only one patient with a multilocular cystic tumour with mural nodules showed low signal intensity on... more

Figure 1. Axial plane T2-WI of the pelvis showing a large unilocular cystic tumour with mural nodules originating on the right ovary.
Figure 2. Sagittal plane T2-WI of the pelvis showing a large multilocular cystic tumour with mural nodules.


In this study, clear cell carcinoma of the ovary most frequently presented as a large unilateral cystic tumour with mural nodules. The solid component most frequently presented an intermediate signal on T2-WI. The cystic component can be uni or multilocular and its content can appear pure (high signal on T2-WI and low on T1-WI) or proteinaceous/haemorrhagic. In the clear cell carcinomas associated with endometriosis, the latter might be explained by the presence of degenerated blood products of endometriotic cysts.

One of our patients presented with solid tumours with low signal on T2-WI on both ovaries. This case turned out to be a borderline adenofibroma with foci of clear cell intraepithelial carcinoma. Thus, when a patient with clear cell carcinoma presents with bilateral low signal solid tumours, there could be because of association with clear cell adenofibroma [3].... more