Neuroendocrine carcinoma arising in a tailgut cyst. (2018) - Al Khaldi, Maher
Highlights: A tailgut cyst, also called retrorectal cystic hamartoma, is a rare congenital lesion that forms most commonly in the retrorectal space. They are often misdiagnosed and can rarely transform into neuroendocrine tumours. A complete surgical resection is required upon diagnosis, preferably by a posterior approach when feasible. Final diagnosis is made with the histopathological examination of the resected mass and appropriate follow-up must be ensured. Abstract: Introduction: A tailgut cyst, also called retrorectal cystic hamartoma, is a rare congenital lesion that forms most commonly in the retrorectal space. It is presumed to arise from remnants of early embryogenesis. Presentation of Case: The following report describes a unique case of a retrorectal cystic hamartoma in a 53 year-old French Canadian man with a history of low back pain. The tumour underwent malignant transformation into a well-differentiated neuroendocrine carcinoma three years after the beginning of symptoms. Discussion: This condition can be found at any age, but occurs especially among middle-aged women. Not only is it frequently misdiagnosed, but also several complications associated to the cyst have been reported such as infection and malignant transformation. This is why complete surgical excision of the tailgut cyst is currently recommended.