Recurrent retrorectal tailgut cyst mimicking deep pelvic abscess: A diagnostic dilemma

Tailgut Cyst-Gynecologist's Pitfall: Literature Review and Case Report

Background and Clinical Significance: Retrorectal cystic hamartomas ("Tailgut cysts") are rare developmental cysts that appear in the retrorectal space, arising from aberrant remnants of the post-anal primitive gut in case of an incomplete embryogenetic involution. Case Presentation: We present the case of a 30-year-old woman with a history of chronic lower abdominal pain. Other digestive symptoms, like rectal fullness, constipation, pain on defecation, rectal bleeding or genitourinary obstruction symptoms, were not associated. During a period of 3 years, she underwent several surgical procedures for ovarian cysts, without relieving the symptomatology. A computed tomography (CT) scan showed a presacral tumor with a right pararectal development. A surgical resection of the lesion using an anterior approach was performed, with the final pathological diagnosis of a retrorectal cystic hamartoma ("tailgut cyst"). Conclusions: This case underlines the fact that retrorectal masses can be challenging to diagnose, and tailgut cysts must be taken into consideration in cases of perirectal tumors in patients with a history of multiple failed procedures and surgeries.

Development of Pseudosacral Cyst Following Surgery for Primary Presacral Neuroendocrine Tumors With Liver Metastasis: A Case Report

Presacral neuroendocrine tumor (PSNET) is a rare disease that currently lacks a standardized treatment approach. In this report, we present a unique case of PSNET with liver metastasis that progressed into a pseudosacral cyst following complete surgical resection and sulfatinib treatment with radiofrequency ablation. Before undergoing surgical treatment for presacral neuroendocrinology, it is important to consider the potential risks of poor healing of the presacral incision and formation of pseudocysts. These complications may be caused by various factors, including the procedure itself and the use of targeted drugs.

A neuroendocrine tumor arising in a tailgut cyst: Case report and literature review

INTRODUCTION AND IMPORTANCE

Cystic lesions in the retrorectal space include developmental abnormality, inflammatory process, and tumor-relevant cysts. Among them, the tailgut cyst is the most common lesion which is featured by the complex epithelium lining the wall. It is generally accepted that tailgut cysts are embryonic residues and are mostly benign, but there are also reports about malignant transformation and even metastasis.

CASE PRESENTATION

A 44-year-old female complained a sacrococcygeal discomfort more than one year. The imaging diagnosis was an infectious cyst. After surgery, a solid region was defined in a cyst. Morphologically, the region was composed of bland epithelia forming glandular or ribbon-like structure, with round nuclei and fine chromatin. Immunohistochemically, the cells were positive for CK7, CD56 and synaptophysin. The Ki-67-positive cells were about 1 %. The final diagnosis is a low-grade neuroendocrine tumor arising in a tailgut cyst. The patient was living without recurrence by the follow-up of 20 months after surgery.

CLINICAL DISCUSSION

By reviewing the previously reported NET arising from tailgut cysts, we summarized 29 cases of neuroendocrine neoplasms that reported detailed information, and the majority are women. We found that the higher-grade tumor presented a higher tendency of distant metastasis or recurrence after surgery. Complete resection and full evaluation by pathologists are necessary to get a correct diagnosis and avoid disease progression.

CONCLUSION

We reported the rare case of NET G1 arising from a tailgut cyst and reviewed relevant reports, in order to broaden differential diagnoses when an isolated mass is identified in the retrorectal space.