Rectal Cancer Diagnosed after Cesarean Section in Which High Microsatellite Instability Indicated the Presence of Lynch Syndrome

Abstract

We report a case of rectal cancer with microsatellite instability (MSI) that probably resulted from Lynch syndrome and that was diagnosed after Cesarean section. The patient was a 28-year-old woman (gravid 1, para 1) without a significant medical history. At 35 gestational weeks, vaginal ultrasonography revealed a 5 cm tumor behind the uterine cervix, which was diagnosed as a uterine myoma. The tumor gradually increased in size and blocked the birth canal, resulting in the patient undergoing an emergency Cesarean section. Postoperatively, the tumor was diagnosed as rectal cancer with MSI. After concurrent chemoradiation therapy, a lower anterior resection was performed. The patient's family history revealed she met the criteria of the revised Bethesda guidelines for testing the colorectal tumor for MSI. Testing revealed that the tumor did indeed show high MSI and, combined with the family history, suggested this could be a case of Lynch syndrome. Our findings emphasize the importance of considering the possibility of Lynch syndrome in pregnant women with colorectal cancer, particularly those with a family history of this condition. We suggest that the presence of Lynch syndrome should also be considered for any young woman with endometrial, ovarian, or colorectal cancer.

Colorectal Cancer During Pregnancy–Case Report and Brief Review of The Literature

“…CRC is among the eight most common malignancies in pregnancy [7]. Although its incidence is rare, it is associated with serious consequences for both the mother and even the fetus [8]. Its clinical manifestation, diagnosis, and treatment options seem a big challenge in front of treating physicians [9][10][11][12][13].…”

“…Our patient had experienced an intermittent abdominal pain all over her pregnancy with moderate anemia. Common presentations of CRC including abdominal pain, nausea, vomiting, anemia, and rectal bleeding usually masked by pregnancy and it is truly hard to distinguish these symptoms of what is considered as warning signs of CRC [2,[3][4][5][6][7][8][9][10][11][12][13][14]. This delay would lead to late diagnosis of the disease and subsequently poor prognosis.…”

“…Colonoscopy which is routinely used in nonpregnant women is relatively contraindicated due to the potential mother and fetus risks and also fetal exposure to potential teratogens [16] and only should be performed with cautions. Due to radiation exposure, abdominal CT scan is not recommended specially in the first trimester [7,8,9]. Alternatively, ultrasonography and magnetic resonance imaging (MRI) could be applied; however, the sensitivity of sonography for detection of micrometastasis is not as high as CT imaging and MRI risks are not fully understood in pregnancy [10,11].…”

“…Maybe the increased levels of estrogen and progesterone during pregnancy stimulate the growth of tumoral cells with such receptors; however, all reports did not support this hypothesis. Slattery et al in a study found only one case with positive progesterone receptor among 156 pregnant cases with CRC [2][3][4][5][6][7][8][9][10][11]. The elevated amounts of Cox-2 in CRC patients has raised the hypothesis of its association with colorectal cancer; however, there are little evidences to elucidate its carcinogenic role.…”