Tailgut cyst: A case report in a 9-month-old infant

Two Cases of Symptomatic Tailgut Cysts

Tailgut cysts are rare lesions which are found in the rectorectal space. They develop in the final section of the intestine from which the rectum and anus extend and vary from being asymptomatic to symptomatic due to pressure on organs or nerves. Tailgut cysts are more common in females, usually between 30 and 60 years of age. They are thought to be benign, with variable malignancy risks. Surgical excision followed by histological examination is the gold standard of treatment, but access and approach to tailgut cysts depend on the location and morphology of the lesion. We present two symptomatic cases of this very rare pathology. In both cases, the cyst and coccyx bone were successfully excised using different approaches. The first patient was a 40-year-old woman with a large cyst which caused morning tenesmus, urinary outflow disorders and painful ovulation. Due to the cyst size, laparotomy was performed, and a combined approach was used. The second patient is a 36-year-old woman with co-existing endometriosis and a cyst causing pain in the sacral spine, constipation and tenesmus. The tumor was excised using a Kraske approach, and due to the infiltration of the coccyx bone it was removed using an osteotome. In this patient, perforation of the cyst was also observed. Both patients completed follow-ups involving regular surgical check-ups and MRI scans. Descriptions of different symptoms and surgical approaches make our study an important source of knowledge for diagnosing and treating these very rare tumors.

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

AIM

The best treatment for tailgut cysts has not been firmly established. We report a systematic review of the cases in the available literature in order to provide an evidence base for treatment.

METHOD

A systematic search of articles wholly or partly in English was made of PubMed, Embase and Google Scholar; additional studies were discovered by searching reference lists and contacting authors directly. Search terms 'tailgut cyst', 'tail gut cyst', 'retrorectal hamartoma' and 'retrorectal tumour' were used for case reports or case series; no publication date restrictions were imposed. Only studies with histological confirmation of diagnosis and reporting the age and gender of patients were included. Papers were excluded by consensus between the first two authors.

RESULTS

A total of 196 individual cases were analysed in detail including 51 cases of neoplasia. The overall rate of neoplastic transformation was 26.6%. Although the male:female cyst incidence ratio was 1:4, men over 18 had a significantly greater relative risk of neoplasm at 1.94 (P = 0.0055). Radiological evidence of nodular thickening of the cyst wall significantly increased the relative risk of the presence of cancer (P = 0.0023).

CONCLUSIONS

Current orthodoxy that these are not dangerous embryological remnants is unfounded and may be false. The available data suggest the risk of malignant transformation is high and will apply to any residual tissue after excision. The same rationale behind total mesorectal excision in rectal cancer applies to tailgut cysts. Consequently they should be resected with similar oncological margins.