A well-differentiated neuroendocrine tumor (Grade I) arising in a tailgut cyst

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.

Presacral tumors: A systematic review of literature

Presacral/Retrorectal tumors (RRT) are rare lesions that comprise a multitude of histological types. Data on surgical management are limited to case reports and small case series. The aim of the study was to provide a comprehensive review of the epidemiology, pathological subtypes, surgical approaches, and clinical outcomes. A PubMed search using terms "retrorectal tumor" and "presacral tumor" was used to identify articles reporting RRT of non-urological, non-gynecologic, and non-metastatic origin. Articles included were between 2015 and 2023. A total of 68 studies were included, comprising 570 patients. About 68.2% of patients were female, and the mean overall age of both sexes was 48.6 years. Based on histopathology, 466 patients (81.8%) had benign lesions, and 104 (18.2%) were malignant. In terms of surgical approach, 191 (33.5%) were treated anteriorly, 240 (42.1%) through a posterior approach, and 66 (11.6%) combined. The mean length of stay was 7.6 days. Patients treated using the posterior approach had a shorter length of stay (5.7 days) compared to the anterior and combined approaches. RRT are rare tumors of congenital nature with prevalence among the female sex. R0 resection is crucial in its management, and minimal access surgery appears to be a safer option in appropriate case selection.

Robotic approach to remove four tailgut cyst cases in Brazil: a case series

Tailgut cysts are rare congenital lesions that are remnants of the embryonic hindgut. This abnormality presents with non-specific symptoms or no symptoms; therefore, misdiagnosis is common. Here, we present four cases of tailgut cysts that were successfully removed using a robotic surgical approach. A 42-year-old woman with tenesmus, pain in the right gluteal region, and discomfort in the rectal region during evacuation was referred to our medical center. Another patient was a 28-year-old woman who presented with the same symptoms to our general practitioner. Both patients underwent upper abdominal and pelvic magnetic resonance imaging that revealed a tailgut cyst. Further, a 36-year-old woman was referred with coccyx and hypogastric pain. Magnetic resonance imaging revealed two pararectal cystic formations. She underwent robot-assisted surgery, and after analysis by a pathologist, the conclusion was that the tailgut cyst was associated with scarring fibrosis. A 55-year-old woman with posterior epigastric pelvic pain associated with heartburn underwent robot-assisted surgery to resect a retroperitoneal tumor. These cases highlighted the importance of tailgut cysts in the differential diagnosis of rectal lesions. Surgical treatment is preferred because malignant transformations can occur. The difference between laparoscopic and robotic approaches is the better visualization and stability of the latter, inducing less tissue damage. Robotic resection is a safe procedure, especially in patients with a narrow pelvis, because it reduces tissue damage.

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.

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.

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.