Neuroendocrine tumour arising inside a retro-rectal tailgut cyst: report of two cases and a review of the literature

Liver metastases of a neuroendocrine tumor arising from a tailgut cyst treated with interventional locoregional therapies: a case report and review of the literature on recurrent cases

A tailgut cyst is a rare, developmental cyst occurring in the presacral space. Although primarily benign, malignant transformation is a possible complication. Herein, we report a case of liver metastases after resection of a neuroendocrine tumor (NET) arising from a tailgut cyst. A 53-year-old woman underwent surgery for a presacral cystic lesion with nodules in the cyst wall. The tumor was diagnosed as a Grade 2 NET arising from a tailgut cyst. Thirty-eight months after surgery, multiple liver metastases were identified. The liver metastases were controlled with transcatheter arterial embolization and ablation therapy. The patient has survived for 51 months after the recurrence. Several NETs derived from tailgut cysts have been previously reported. According to our literature review, the proportion of Grade 2 tumors in NETs derived from tailgut cysts was 38.5%, and four of the 5 cases of Grade 2 NETs (80%) relapsed, while all eight cases of Grade 1 NETs did not relapse. Grade 2 NET may be a high-risk group for recurrence in NETs arising from tailgut cysts. The percentage of Grade 2 NETs in tailgut cysts was higher than that of rectal NETs, but lower than that of midgut NETs. To the best of our knowledge, this is the first case of liver metastases of a neuroendocrine tumor arising from a tailgut cyst that was treated with interventional locoregional therapies, and the first report to describe about the degree of malignancy of neuroendocrine tumors originating from tailgut cysts in terms of the percentage of Grade 2 NETs.

Retrorectal tumors: A challenge for the surgeons

Retrorectal or presacral tumors are rare lesions located in the presacral area and considered as being derived from multiple embryological remnants. These tumors are classified as congenital, neurogenic, osseous, inflammatory, or miscellaneous. The most common among these are congenital benign lesions that present with non-specific symptoms, such as lower back pain and change in bowel habit. Although congenital and developmental tumors occur in younger patients, the median age of presentation is reported to be 45 years. Magnetic resonance imaging plays a crucial role in treatment management through accurate diagnosis of the lesion, the evaluation of invasion to adjacent structures, and the decision of appropriate surgical approach. The usefulness of preoperative biopsy is still debated; currently, it is only indicated for solid or heterogeneous tumors if it will alter the treatment management. Surgical resection with clear margins is considered the optimal treatment; described approaches are transabdominal, perineal, combined abdominoperineal, and minimally invasive. Benign retrorectal tumors have favorable long-term outcomes with a low incidence of recurrence, whereas malignant tumors have a potential for distant organ metastasis in addition to local recurrence.

Multicenter Analysis of Presacral Neuroendocrine Neoplasms-Clinicopathological Characterization and Treatment Outcomes of a Rare Disease

Background and Aims

Neuroendocrine neoplasms (NENs) of the presacral space are an extremely rare disease entity with largely unknown outcome and no established standard of care treatment. Therefore, we wanted to analyze clinical presentation, histopathological findings, treatment outcomes, and prognosis in a multicentric patient cohort.

Methods

We searched local databases of six German NEN centers for patients with presacral NEN. Retrospective descriptive analyses of age, sex, stage at diagnosis, symptoms, grade, immunohistochemical investigations, biomarkers, treatment, and treatment outcome were performed. Kaplan-Meier analysis was used to determine median overall survival.

Results

We identified 17 patients (11 female, 6 male) with a median age of 50 years (range, 35-66) at diagnosis. Twelve cases presented initially with distant metastases including bone metastases in nine cases. On pathological review the majority of patients had well-differentiated G2 tumors. Immunohistochemical profile resembled rectal NENs. All but one patient had non-functioning tumors. Somatostatin receptor imaging was positive in 14 of 15 investigated cases. Eight patients were treated surgically including palliative resections; 14 patients received somatostatin analogs with limited efficacy. With 14 PRRTs completed, 79% showed clinical benefit, whereas only one patient with neuroendocrine carcinoma (NEC) responded to chemotherapy. Treatment with everolimus in three patients was not successful, whereas cabozantinib resulted in a disease stabilization in a heavily pretreated patient. During a median observation period of 44.5 months, 6 patients died. Median overall survival was not reached.

Conclusion

Presacral NEN are histopathologically similar to rectal NENs. Presacral NEN should be considered as possible primary in NEN of unknown primary. The majority of tumors is non-functioning and somatostatin receptor positive. PRRT demonstrated promising activity; tyrosine kinase inhibitors warrant further investigations. Further molecular characterization and prospective evaluation of this rare tumor entity are needed.

Laparoscopic resection of a neuroendocrine tumor that almost fully replaced tailgut cysts: a case report

Background

Neuroendocrine tumors (NETs) originate from neuroendocrine cells, which are found throughout the body. NETs occur principally in the gastrointestinal tract (approximately 65%) and bronchopulmonary tract (approximately 25%) but rarely occur in the presacral space. Aside from primary and metastatic lesions, there have been reports of NETs occurring in the presacral space arising from tailgut cysts, teratomas, and imperforate anus. We herein report a rare case of laparoscopic resection of a NET in the presacral space, which almost fully replaced tailgut cysts.

Case presentation

A 68-year-old woman was referred to our hospital for surgery of a right inguinal hernia, but preoperative computed tomography revealed an asymptomatic 43-mm mass in the presacral space. Magnetic resonance imaging showed a multilocular solid mass with clear boundaries and a slightly high signal intensity on T1- and T2-weighted images. Positron emission tomography showed 18F-fluorodeoxyglucose uptake. Thus, we suspected a malignant tumor and performed laparoscopic resection to obtain a definitive diagnosis. Macroscopically, the tumor was 43 mm in size with clear boundaries, and the cut surface was a gray-white solid component. Histopathological findings revealed that the tumor was composed of relatively uniform cells with fine chromatin, with round to oval nuclei arranged in solid, trabecular, or rosette-like growth patterns. Small cysts lined with stratified squamous epithelium and columnar epithelium were observed along with solid components of the tumor, which is a feature of tailgut cysts. Therefore, the final diagnosis was NET Grade 1 arising from tailgut cysts. No recurrence was observed within 1 year after surgery.

Conclusions

We performed en bloc laparoscopic resection of a NET arising from tailgut cysts in the presacral space without injury. In cases of a solid lesion in the presacral space, not only the primary disease but also the pathological condition with tissue transformation and replacement should be considered, as in this case.

Currarino triad: A case report of a 48-year-old patient with a neuroendocrine tumor

Currarino triad is a rare syndrome, with less than 250 cases reported, and it includes a combination of sacrococcigeal bony abnormalities, anorectal malformations and the presence of a presacral mass. Here we present a case of a 48-year-old male patient with history of severe chronic constipation, who was incidentally diagnosed with a presacral during imagiological investigation, which was histologically proven to be a neurendocrine tumor.

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.

Neuroendocrine tumour developing within a long-standing tailgut cyst: case report and review of the literature

A tailgut cyst is a rare congenital lesion that can develop in the presacral space from the remnants of an embryonic hindgut. It is unusual for malignant change to occur in a tailgut cyst. We report a case of a large long-standing tailgut cyst, which was removed during a laparotomy. Histopathology showed a well-differentiated neuroendocrine tumour (primary carcinoid tumour) arising in a tailgut cyst. We reviewed the English literature for all adult cases with this condition. All original articles were reviewed, and data were compiled and tabulated. Including this report, 29 cases of NET developing in a tailgut cyst were found in the English literature. Tailgut cysts have been reported as more common in females, with a mean age of presentation in the fifth decade (Devine, in: Zbar A, Wexner S (eds) Coloproctology. Springer specialist surgery series, Springer, London, 2010; Hjermstad and Helwig in Am J Clin Pathol 89:139-147, 1988). Tailgut cysts may undergo malignant change including adenocarcinoma, sarcoma, and NET (Mathis et al. Br J Surg 97:575-579, 2010; Messick in Dis Colon Rectum 61:151-153, 2018; Patsouras et al. in Colorectal Dis 17:724-729, 2015; Chereau et al in Colorectal Dis 15:e476-e482, 2013). It is difficult to estimate the true incidence of malignant change in a tailgut cyst, with the literature reports only limited to case reports and small-case series. Although rare, our case confirms need to consider the possibility of a malignant component, even in a benign process such as a tailgut cyst. This prompts consideration for upfront definitive management.

Surgical and molecular characterization of primary and metastatic disease in a neuroendocrine tumor arising in a tailgut cyst

Neuroendocrine tumors (NETs) arising from tailgut cysts are a rare but increasingly reported entity with gene expression profiles that may be indicative of the gastrointestinal cell of origin. We present a case report describing the unique pathological and genomic characteristics of a tailgut cyst NET that metastasized to liver. The histologic and immunohistochemical findings were consistent with a well-differentiated NET. Genomic testing indicates a germline frameshift in BRCA1 and a few somatic mutations of unknown significance. Transcriptomic analysis suggests an enteroendocrine L cell in the tailgut as a putative cell of origin. Genomic profiling of a rare NET and metastasis provides insight into its origin, development, and potential therapeutic options.

Neuroendocrine carcinoma arising in a tailgut cyst

INTRODUCTION

A tailgut cyst, also called retrorectal cystic hamartoma, is a rare congenital lesion that forms most commonly in the retrorectal space. It is presumed to arise from remnants of early embryogenesis.

PRESENTATION OF CASE

The following report describes a unique case of a retrorectal cystic hamartoma in a 53 year-old French Canadian man with a history of low back pain. The tumour underwent malignant transformation into a well-differentiated neuroendocrine carcinoma three years after the beginning of symptoms.

DISCUSSION

This condition can be found at any age, but occurs especially among middle-aged women. Not only is it frequently misdiagnosed, but also several complications associated to the cyst have been reported such as infection and malignant transformation. This is why complete surgical excision of the tailgut cyst is currently recommended.