Multiple primary malignancies and cancer during pregnancy — a case of two rare consecutive conditions

Cancer during pregnancy is a rare condition involving neoplasm diagnosed during pregnancy or within a year after labor. Cancer symptoms may be masked by pregnancy symptoms, which might delay diagnosis and proper treatment. Another rare phenomenon is the occurrence of multiple primary malignancies. This is defined as the appearance of two or more unrelated neoplasms in one individual, which can be located in the same or various organs. The risk is increased due to advances in cancer treatment, resulting in a growing population of cancer survivors. Since the co-occurrence of both conditions has not been previously described, we present a rare case report of a forty-year-old female patient who received these two diagnoses. The patient with a colorectal cancer family history in her third pregnancy suffered from painful lesions located in the anal area diagnosed as hemorrhoids. In the next pregnancy, the symptoms were not resolved, and the in-depth diagnosis revealed colorectal cancer. The treatment included chemotherapy during pregnancy and radical surgery involving rectum amputation in the post-partum period. Postoperative magnetic resonance imaging (MRI) revealed a fluid lesion located near the posterior vaginal wall. The cyst’s enlargement was observed in the following months, raising oncological concerns. The patient underwent a laparotomy, during which an intraoperative histopathological examination found mucinous endometrioid adenocarcinoma. Optimal cytoreduction was performed, and the patient received post-surgery chemotherapy. The tests performed did not indicate the genetic background of either neoplasm. This case suggests the need for increased oncological vigilance in cancer survivors, as well as pregnant patients.