Malignancy within a Tail Gut Cyst: A Case of Retrorectal Carcinoid Tumour

Abstract

Purpose. Tailgut cysts with malignant transformation are rare entities. We discuss the diagnostic strategy and treatment of a malignancy within a tailgut cyst. Methods. In this study we report on the case of a 61-year-old man with a malignant neuroendocrine tumour arising within a tailgut cyst and an overview of the literature emphasising the histopathological characteristics and differential diagnosis. Results. Our patient presented with lower back pain, rectal pain, and increased urgency of defecation. MRI scan and CT-guided biopsy on histological analysis revealed a diagnosis of carcinoid tumour of the presacral space. The patient subsequently underwent an abdominoperineal excision of the rectum. Conclusions. This case highlights the importance of tailgut cysts as a differential diagnosis of presacral masses. It is a rare congenital lesion developing from remnants of the embryonic postanal gut and is predominantly benign in nature. Approximately half of cases remain asymptomatic; therefore, diagnosis is often delayed. Magnetic resonance imaging is the investigation of choice and an awareness of the possibility of malignant potential is critical to avoiding missed diagnosis and subsequent morbidity. Complete surgical excision allows accurate diagnosis, confirmation of oncological clearance, and prevention of mortality.

Malignant transformation of tailgut cysts is significantly higher than previously reported: systematic review of cases in the literature

“…Neuroendocrine tumours represented 20 cases (39% of all tumours found). Of these, 15 [2,33,36,47,49,53,64,70,93,106,107,115,123,131] were reported either as neuroendocrine carcinomas or metastatic at the time of presentation. There was one case of neuroendocrine tumour arising in a tailgut cyst which was treated by abdominoperineal resection but the patient later went on the develop liver and brain metastasis [107].…”

Transitional cell carcinoma arising in a tailgut cyst

“…A majority of these are well defined, with a benign appearance on histology and imaging. Malignant transformation in TGCs is extremely rare, with only a handful of reported cases in the literature, the majority being squamous cell carcinoma, adenocarcinoma and carcinoid in nature [ 1 , 3 , 4 , 7 ].…”

“…Tailgut cysts (TGCs) in the presacral region are extremely rare entities [ 1 , 2 ]. These retrorectal tumours arise in most cases from tissue remnants of embryological origin [ 3 , 4 ].…”

“…Symptoms vary, ranging from specific symptoms such as constipation, incontinence and sexual dysfunction to vague symptoms of non-specific pelvic and back pain [ 4 ]. Malignant transformation of TGCs is extremely rare, with 23 reported cases in the literature, the greater proportion being adenocarcinoma [ 1 , 6 ].…”

Retrorectal cystic hamartoma: A case report

“…Pre-sacred hamartomas can be a source of perirectal www.casereportsinternational.com Viveiros et al 6 or perianal chronic symptoms and are often difficult to recognize and diagnose. Also, treatment is often poorly oriented, submitting the patient to multiple surgeries before a definitive diagnosis can be obtained [2,3].…”