Pitfalls in the diagnosis of tailgut cysts

Tailgut Cysts with Malignant Transformation: Features, Diagnosis, and Treatment

A tailgut cyst is a type of benign congenital disease that mainly develops in the retro-rectal space. However, malignant transition can occur in some cases of tailgut cysts. Early and precise diagnosis, and proper treatment, are vital for patients with tailgut cysts with malignant transformation. In this review, we aim to summarize the similarities and differences in the diagnosis and treatment methods among the 3 most frequently reported types of tailgut cysts with malignant transformation. In our study, PubMed and Web of Science databases were used to search for the studies and the key words were “tailgut cysts” and “malignancy”. We found 176 articles and selected 75 articles in our survey, with 9 reviews, 35 case reports, and 31 case reports and reviews.

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.

Diagnosis of Tailgut Cyst in Gynecologic Patients: Systematic Review of the Literature

Tailgut cysts, also called retrorectal cystic hamartomas, are rare findings that usually occur in the retrorectal space. The incidence is estimated to be about 1 in 40,000.

The aim of our review is to evaluate the potential pitfalls in the diagnosis of this rare pathologic condition, according to diagnostic procedures for this rare but misleading and subtle entity.

We conducted a Medline literature review of the English literature discussing tailgut cysts in female patients. We concentrated on imaging technology used for diagnosis in gynecologic patients. For our search, we used the key words “tailgut cyst”, “retrorectal cystic hamartoma”, “gynecology”, focusing on clinical presentation, imaging technology used for diagnosis, presence of malignancy, and misdiagnosis with more common gynecologic pathology.

Our search revealed 143 articles during the years 1975–2016 and, of these, 30 articles describing 91 female patients were considered.

We concluded that tailgut cyst should be included in the differential diagnosis of pelvic lesions in gynecologic patients.