Aspiration cytology and core biopsy of a carcinoid tumor arising in a retrorectal cyst: a case report

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.

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.

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.

Neuroendocrine Tumor Arising in a Tailgut Cyst: A Rare Presacral Tumor

A tailgut cyst (retrorectal cystic hamartoma) is an uncommon lesion that develops in the presacral (retrorectal) space. Malignant change in a tailgut cyst is extremely rare and presents as a soft tissue (presacral) or bone (sacral) neoplasm. We report a case of tailgut cyst in which a neuroendocrine tumor developed in a 25-year-old female. Computed tomography and magnetic resonance imaging scans revealed a sacrococcygeal malformation with absent left S4 and S5 and a partly cystic lesion within the right presacral space. Histologically, the lesion contained cystic and solid elements. The cysts were lined by columnar and stratified squamous epithelial cells with underlying patchy smooth muscle. The solid element was a partly necrotic neuroendocrine tumor composed mainly of ribbons of tumor cells, which showed mitotic activity and expressed cytokeratin, chromogranin, and synaptophysin. Histologically, tailgut cysts are lined by epithelium and contain scattered smooth muscle bundles in the cyst wall. Although rare, the possibility of tailgut cyst with neuroendocrine tumor should be included in the differential diagnosis of an enlarging presacral tumor.

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.

The Clinicopathological Aspects of Primary Presacral Neuroendocrine Neoplasms: One Center Experience

OBJECTIVES

Presacral neuroendocrine neoplasms (NENs) are rare entities that are found at the presacral space. We report our experience in the diagnosis, management, and outcomes of primary presacral NENs.

METHODS

This was an institutional review board-approved retrospective review of medical records and surgical pathology specimens of patients with a diagnosis of NENs at Cedars-Sinai Medical Center between January 2000 and April 2016.

RESULTS

Ten patients were identified. The median age at presentation was 38 years (range, 20-77 years), and 8 were women. One patient presented with carcinoid-like symptoms, 2 were diagnosed incidentally, and 7 presented with symptoms related to mass effect. The median size of the tumor was 7.0 cm (range, 3-12 cm). On pathologic review, 3 of 10 were low-grade and well-differentiated, 5 of 10 were intermediate-grade and well-differentiated, 2 of 10 were grade 3 and classified as high-grade and poorly differentiated neuroendocrine tumors. Seven cases were metastatic on presentation with lymph node, liver, lung, or skeletal metastasis. Seven of 8 cases were detectable using Octreoscan. Eight patients were treated with a somatostatin analog and 5 patients were treated surgically.

CONCLUSIONS

Presacral NENs are clinically similar to gastroenteropancreatic tumors. Octreoscan imaging and somatostatin analog therapies were frequently applied. Further biologic characterization of this rare subtype is needed.

Endoscopic ultrasonography and rectal duplication cyst in an adult

Rectal duplication cysts account for 4% of all duplications of the alimentary tract. Presentation in adulthood is rare. An asymptomatic 54-year-old man was referred for endoscopic colorectal cancer screening. A bulging mass covered by normal mucosa was identified in the rectum. Endoscopic ultrasonography (EUS) with fine needle aspiration (FNA) was made for a diagnosis of rectal duplication cyst. The patient was operated and the diagnosis was confirmed. The diagnosis of the rectal duplication cyst is a challenge. EUS may have a singular role when identifying a muscular layer, because this is the only absolutely necessary criterion for the diagnosis. FNA by EUS may eventually identify colorectal and/or heterotypic epithelium that are the other diagnostic criteria of the duplication cyst.

Neuroendocrine tumor arising from tailgut cyst with spinal cord tethering: case report and literature review

BACKGROUND CONTEXT

Neuroendocrine tumors (NETs) from tailgut cysts are rare; only 15 cases have been reported until now. A tailgut cyst with spinal cord tethering has not been previously reported, although both diseases are congenital anomalies in the early stage of gestation.

PURPOSE

To report a rare case of NET from tailgut cyst associated with spinal cord tethering and review the literature.

STUDY DESIGN

Case report and literature review.

METHODS

We describe the clinical course of a 53-year-old man, who presented with gluteal pain and bladder dysfunction. Magnetic resonance images showed that a tumor of the sacral spinal canal extended into the retrorectal space and connected to a thickened fatty filum terminale, which was tethering the spinal cord.

RESULTS

Because of tumor malignancy on a computed tomography-guided biopsy and the imaging data of involvement of presacral lymph nodes, we performed total removal of the tumor. Pathologic examination revealed NET (Grade 2) arising from a tailgut cyst. The patient received somatostatin analog therapy after surgery, followed by local radiation because of the further enlargement of the lymph nodes. Later, we started everolimus therapy for the metastases to the retroperitoneal lymph nodes. He presented with no local recurrence or further disease progression at 28 months after surgery. The review indicated that tumors in Grade 2 or 3 showed progressive clinical course after surgery and three of seven patients with biopsy were misdiagnosed.

CONCLUSIONS

The correct preoperative diagnosis of NETs from tailgut cysts is difficult, but extremely important because Grade 2 or 3 tumors show disease progression even after surgery. Presacral congenital tumors, such as tailgut cysts, have the potential of malignant transformation into neuroendcrine tumors or adenocarcinomas. Comorbidity of spinal cord tethering and tailgut cyst suggests some relationship to common developmental errors in embryogenesis.

A Unique Retrorectal Tumor With Neuroendocrine Differentiation

Retrorectal or presacral tumors are very rare. We report a unique case of a retrorectal tumor with neuroendocrine differentiation, consisting of high- and low-grade components. A 53-year-old woman treated for a perianal abscess at another clinic was referred to our hospital for continued anal pain. Digital rectal examination identified a soft tumor with a smooth surface in the lower rectum. Pelvic computed tomography and magnetic resonance imaging detected a large cystic tumor measuring 8 cm in diameter in the retrorectal space of the pelvis. The border between the tumor and rectal wall, levator ani and vaginal wall was obscure. Fine-needle aspiration cytology was highly suggestive of carcinoma. Abdominoperineal resection was performed, and the tumor was histologically diagnosed as a neuroendocrine carcinoma based on immunohistochemical staining. No previous case has been reported with cystic growth of a neuroendocrine carcinoma in the retrorectal space.

Ghrelin-producing well-differentiated neuroendocrine tumor (carcinoid) of tailgut cyst. Morphological, immunohistochemical, ultrastructural, and RT-PCR study of a case and review of the literature

Well-differentiated neuroendocrine tumors (carcinoids) arising in the presacral space are rare neoplasms that can arise in association with either sacrococcygeal teratomas or tailgut cysts. Although tumors arising in tailgut cysts are more frequent than those associated with teratomas, they are still very rare, and only 13 cases have been reported in the literature. We describe the first case of a carcinoid composed of ghrelin-producing cells arising in a tailgut cyst. Ghrelin production was demonstrated using immunohistochemistry, electron microscopy, and reverse transcription-polymerase chain reaction methods. A 73-year-old woman with back and pelvic pain was found to have a presacral mass histologically diagnosed, on needle biopsy, as a well-differentiated neuroendocrine tumor. Workup did not show another primary tumor or metastatic disease. The patient underwent laparoscopic resection of the mass, and the pathological diagnosis of the surgical specimen was of a tailgut cyst-associated carcinoid composed of ghrelin-producing cells. In addition, we have accurately reviewed the literature on presacral carcinoids, associated or unassociated with tailgut cysts, to give the reader a comprehensive overview of these very rare tumor types.

Primary neuroendocrine tumor of the sacrum: case report and review of the literature

Primary carcinoid tumor (well-differentiated neuroendocrine tumor) of the bone involving the sacrum is extremely rare. We report the case of a 72-year-old man who presented with a 20-year history of intermittent low back pain and was found to have an intraosseous sacral mass on imaging. A needle biopsy revealed that this lesion was a well-differentiated neuroendocrine tumor. Workup did not show any primary tumor or other metastatic disease. There was no associated tailgut cyst or sacrococcygeal teratoma. The lesion was treated with radiation therapy because a surgical approach was rejected. The patient is free of metastatic disease after 28 years evolution of the lesion, retrospectively seen to be present on a conventional radiography performed in 1980. A review of the literature revealed 20 case reports of neuroendocrine tumors arising from the presacral region (with or without associated tailgut cyst or sacrococcygeal teratoma) and sometimes extending to the sacrum. One additional case was located within the neural canal and involved the sacrum, the presacral region, and the rectal wall. Our case is the only tumor arising primarily from the sacrum. The long evolution of this lesion without any other location makes metastatic disease very improbable and this case appears to be a unique example of primary intraosseous sacral carcinoid tumor.

Retrorectal epidermoid cyst in an elderly woman: report of a case

An epidermoid cyst is a common occurrence in the skin. Such a cyst occurring in the retrorectal space, however, is extremely rare. We herein present a case of retrorectal epidermal cyst in a 67-year-old Japanese woman. She reported no symptoms and a perirectal mass behind the lower rectum was accidentally detected by computed tomography (CT). Contrast CT and magnetic resonance imaging revealed a cystic mass (76x70x63 mm) with a slightly enhanced thin wall which was attached to the lower rectum. The patient underwent surgery via a posterior approach. The mass was exposed after an excision of subcutaneous fat and was firmly adhered to the anal sphincter muscle. The cystic mass was completely removed without a proctectomy. Histologically, the cyst was diagnosed to be an epidermoid cyst. The postoperative course was uneventful, and the patient was discharged on postoperative day 9. A diagnosis of retrorectal cystic tumor is difficult, and a complete resection is necessary for the treatment of such tumors.

Primary presacral neuroendocrine tumor associated with imperforate anus

Background

Presacral masses are unusual growths that have a limited differential diagnosis, typically not including neuroendocrine tumors (NETs). Classically, NETs are well-differentiated gastroenteropancreatic tumors of probable benign behavior. These tumors are associated with a typical morphologic pattern and involve the distal colon, rectum, and genitourinary tract; they are considered less aggressive, frequently asymptomatic, and rarely cause carcinoid syndrome, even when metastatic. Neuroendocrine tumors of the presacral region are extremely rare and few have been described in the literature. They have not been previously reported as being associated with imperforate anus.

Case presentation

We present an interesting case of a woman with a history of imperforate anus that was found to have a primary neuroendocrine tumor of the presacral region with no rectal wall involvement.

Conclusion

We argue that this is a primary gastroenteropancreatic neuroendocrine tumor which likely originated from cells of hindgut origin that underwent an abnormal migration during embryonic development.

Unusual retrorectal lesion

Retrorectal lesions are rare entities. We report the complete clinicopathological details of an unusual retrorectal lesion composed of low-grade endometrioid adenocarcinoma and propose that this is a malignant change in pluripotent cells arising within a long-standing retrorectal tailgut lesion. To the best of our knowledge, this is the first case report of this malignancy in a retrorectal tailgut cyst.