Ovarian metastases occur in about 6% of primary colorectal cancer patients undergoing surgery [1, 2]. These lesions occur mostly when the primary colorectal cancer (CRC) is already in an advanced state, and distant metastases to other sites are frequently found together [3].
The most common primary tumours metastasizing to ovaries are those from the breast, pancreas, and gastrointestinal tract cancers, also commonly referred to as Krukenberg’s tumours [4].
In this case, the presumptive diagnosis of Krukenberg’s tumours was confirmed by the anatomopathological examination.
Misreading the metastasis as a primary tumour can compromise the therapeutic options, leading to adverse consequences to the patient [1, 2].
Preoperative diagnosis is difficult, despite the advances in general imaging, due to the absence of specific clinical and radiological features that could discriminate between primary or secondary tumours [1, 4].
Although a gastrointestinal symptom can lead us to the primary tumour, it isn't rare to have only gynaecological symptoms at presentation [5].
Generally, ovarian metastases are synchronous rather than metachronous [1].
The spreading mechanisms from the ovarian metastases are unclear. Haematogeneous spread is likely to be the main mechanism [3, 5], but some authors refer lymphatic and transcoelomic dissemination as a common mechanism of spread. The latter is sustained by synchronized peritoneum involvement in many cases, but when the metastatic tumour is in a non-superficial position, transcoelomic spread seems improbable [3].
Beside this spectrum of dissemination presentations, some women who present to CCR surgery have isolated ovarian metastases (approximately 3%) [3].
As stated before, differentiating between a primary ovarian cancer and a colon cancer disseminated to the ovaries can be difficult. Some imaging features that help in the differential diagnosis, in favour of colon cancer spreading to the ovaries rather than an ovarian primary, are: bilateral lesions, mass with sharp margins, mass with an oval shape, and T2W hypointense solid components [1, 4, 6].
The literature doesn't state a strong correlation between a specific colon segment and ovarian metastases, and in fact a primary tumour originating in all parts of the colon may disseminate to the ovaries. Hence, the natural frequency from the primary tumour is the most important determinant for the radiologist to check for the site of the primary tumour. Some studies state that there is no relationship between ovarian metastasis and the size of primary CRC [3].
The overall prognosis is poor and aggressive surgery can be an option but in the presence of peritoneal or liver metastases the median survival time is short, and a palliative approach can be the recommended option [2, 5].