Retrorectal Mucinous Adenocarcinoma Arising from a Tailgut Cyst: A Case Report

Mucinous adenocarcinoma arising from a tailgut cyst: A case report

BACKGROUND

Retrorectal hamartomas or tailgut cysts (TCs) are rare. In most cases, they are asymptomatic and benign; however, rarely, they undergo malignant transformation, mainly in the form of adenocarcinoma.

CASE SUMMARY

A 55-year-old woman presented to our hospital with lower back pain. On magnetic resonance imaging, a large pelvic mass was found, which was located on the right of the ischiorectal fossa, extending to the minor pelvis. The patient underwent extensive surgical resection of the lesion through the right buttock. Histological examination confirmed the diagnosis of a retrorectal mucinous adenocarcinoma originating from a TC. Surgical resection of the tumour was complete, and the patient recovered without complications. The pilonidal sinus was then excised. One year later, semi-annual positron emission tomography-computed tomography and magnetic resonance imaging scans did not reveal any evidence of local recurrence or metastatic disease.

CONCLUSION

Preoperative recognition, histological diagnosis, and treatment of TCs pose significant challenges. In addition, the possibility of developing invasive mucinous adenocarcinoma, although rare, should be considered.

Retrorectal mucinous adenocarcinoma arising from a tailgut cyst: A case report and review of literature

BACKGROUND

Tailgut cysts are defined as congenital cysts that develop in the rectosacral space from the residue of the primitive tail. As a congenital disease, caudal cysts are very rare, and their canceration is even rarer, which makes the disease prone to misdiagnosis and delayed treatment. We describe a case of caudal cyst with adenocarcinogenesis and summarize in detail the characteristics of cases with analytical value reported since 1990.

CASE SUMMARY

A 35-year-old woman found a mass in her lower abdomen 2 mo ago. She was asymptomatic at that time and was not treated because of the coronavirus disease 2019 pandemic. Two weeks ago, the patient developed abdominal distension and right waist discomfort and came to our hospital. Except for the high level of serum carcinoembryonic antigen, the medical history and laboratory tests were not remarkable. Magnetic resonance imaging showed a well-defined, slightly lobulated cystic-solid mass with a straight diameter of approximately 10 cm × 9 cm in the presacral space, slightly high signal intensity on T2-weighted imaging, and moderate signal intensity on T1-weighted imaging. The mass was completely removed by laparoscopic surgery. Histopathological examination showed that the lesion was an intestinal mucinous adenocarcinoma, and the multidisciplinary team decided to implement postoperative chemotherapy. The patient recovered well, the tumor marker levels returned to normal, and tumor-free survival has been achieved thus far.

CONCLUSION

The case and literature summary can help clinicians and researchers develop appropriate examination and therapeutic methods for diagnosis and treatment of this rare disease.

Squamous cell carcinoma arising in a tailgut cyst: role of radiotherapy

Tailgut cysts (TGCs) are rare tumours which can undergo malignant transformation. The gold standard of treatment is complete surgical excision. Multidisciplinary assessment is advisable in order to apply adjuvant treatment. Postoperative radiotherapy should be given in case of compromised surgical margins or other factors such as high histological grade or perineural and lymphovascular invasion. Here, we present a case of a squamous cell carcinoma arising from a retrorectal TGC treated with surgery and postoperative radiotherapy and review the main indications and techniques of this therapy.

Nonpolypous Hamartomas of the Gastrointestinal Tract: An Updated Review on Classification, Denominations, and Clinical Management

PURPOSE

To perform the first systematic report about histological subtypes of nonpolypous hamartomas of the gastrointestinal (GI) tract, from esophagus to anal canal.

DESIGN

From over 19,000 studies about hamartomas, most of them published as case series or case presentations, we have selected the most representative ones for the GI tract, excluding polyposis syndromes. To have a whole picture of these hamartomas, all of the data were combined with the personal experience of the authors who are GI pathologists.

RESULTS

The examined articles showed predominance of vascular and combined vascular and mesenchymal hamartomas. Arteriovenous hamartomas or Brunner gland hamartomas are mainly diagnosed in the small intestine, with preponderance for duodenum. Other malformations such cavernous hamartomas are more specific for the colorectal segments, whereas chondromatous hamartomas or those derived from the neural ectoderm were mostly reported in the esophagus. As newly recognized entities were admitted in the last years, misdiagnosis is frequent, and the best therapeutic approach is far to be known.

CONCLUSION

Even rare, hamartomas of the GI tract need to be differentiated from tumors and familial polyposis syndromes. Knowing their proper denominations and possible complications is valuable for gastroenterologists, pathologists, and surgeons, to be aware in the differential diagnosis.