The mermaid syndrome, also known as sirenomelia, is considered an extremely rare congenital developmental disorder characterized by anomalies of the lower spine and lower limbs. Affected babies are born with partial or total leg fusion. Sirenomelia is thought to affect one in every 60,000 to 100,000 infants. We report a case of sirenomelia occurring in a 28-year-old multiparous woman, a heavy smoker with gestational diabetes. In the other 5 pregnancies, however, she gave birth to normal babies. The post mortem examination completed the diagnosis, revealing also multiple malformations of several systems: respiratory, gastro-intestinal, genito-urinary and cardiovascular. In our full term neonate case with grade VI sirenomelia, the presence of a single umbilical artery plus the abdominal aorta with an aberrant trajectory that ends in the umbilical cord differentiates this condition from caudal regression syndrome and also explains the under-development of pelvic organs (secondary to vascular steal phenomena).

According to the latest data provided by Globocan 2020, the incidence of colorectal cancer ranks third, after lung cancer and breast cancer, becoming a more and more important global health issue. Of the cases diagnosed with colorectal cancer, more than 25% are diagnosed in the metastatic stage, with the presence of secondary tumours more frequently in the liver, lung, and bone. Skin metastasis from colorectal cancer are still rare (< 4%). We present a rare, unique case in our department of a 74-year-old patient diagnosed 9 years ago with a malignant rectal tumour, who, after a disease-free period of approximately 8 and a half years, developed multiple skin metastases of rectal adenocarcinoma.