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

Abstract

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.

Promoting Laparoscopic Anterior Approach for a Very Low Presacral Primary Neuroendocrine Tumor Arising in a Tailgut Cyst

“…Although tailgut cysts are benign congenital hamartomas [8], they may undergo malignant transformation, resulting in adenocarcinomas, sarcomas, or NETs [10]. Although common in the appendix [11], only 29 cases of NETs developing in a tailgut cyst have been reported in the literature [12,13].…”

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

“…12 Surgical extirpation will provide an adequate specimen for definite histopathological diagnosis and will serve as definitive treatment in most cases. [13][14][15] Malignant transformation of a TGC is not very common, ranging from 2% to 13% of the cases. 16 In a recent series of 52 retrorectal tumours, 56% were TGCs, and only four were malignant (Carpelan-Holmström 2020).…”

“…Biopsy should be performed only in unresectable cases 12. Surgical extirpation will provide an adequate specimen for definite histopathological diagnosis and will serve as definitive treatment in most cases 13–15…”

Epidemiology, diagnostic approach and therapeutic management of tailgut cysts: A systematic review

“…4,5 Most of patients are asymptomatic or may present non-specific symptoms, including abdominal pain, rectal bleeding, tenesmus and urinary frequency. [6][7][8] Therefore, TGCs still remain a diagnostic challenge for physicians and their diagnosis is usually delayed. 9 Although ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) constitute useful tools for detecting and localizing the primary cystic lesion, a definitive diagnosis relies only on histological examination.…”

“…TGCs are extremely rare presacral entities that could be presented in all ages, but most commonly in middle‐aged women 4,5 . Most of patients are asymptomatic or may present non‐specific symptoms, including abdominal pain, rectal bleeding, tenesmus and urinary frequency 6‐8 . Therefore, TGCs still remain a diagnostic challenge for physicians and their diagnosis is usually delayed 9 …”