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

Tailgut cysts are rare congenital lesions presenting as retrorectal space masses. They can occur in all age groups. Patients often present with ill-defined nonspecific symptoms and the diagnosis if often delayed. Malignancy arising in a tailgut cyst is an even rarer and unique occurrence. A precise diagnosis can be made only after complete excision and histopathological examination of the retrorectal space mass. We describe here a case of a 63-year-old male presenting with chronic constipation, who was diagnosed with a well-differentiated neuroendocrine tumor (Grade I) arising in a tailgut cyst after surgical excision.

Single-center Experience of 24 Cases of Tailgut Cyst

PURPOSE: Tailgut cysts are rare congenital or developmental lesions that arise from vestiges of the embryological hindgut. They are usually present in the presacral space. We report our single-center experience with managing tailgut cysts. METHODS: We conducted a retrospective analysis of 24 patients with tailgut cyst treated surgically at the Colorectal Surgery Department of Severance Hospital, Yonsei University, Seoul, South Korea, between 2007–2018. RESULTS: This study included 24 patients (18 females) with a median age of 51.5 years (range, 21–68 years). Ten cases were symptomatic and 14 were asymptomatic. Cysts were retrorectal in 21 patients. Cysts were below the coccyx level in 16 patients, opposite the coccyx in 6, and above the coccyx in 2. Cysts were supralevator in 5 patients, had a supra- and infralevator extension in 18 patients, and were infralevator in 1. Ten patients were managed using an anterior laparoscopic approach, 11 using a posterior approach, and 3 using a combined approach. Mean cyst size was 5.5 ± 2.7 cm. Postoperative complications were Clavien-Dindo (CD) classification grade II in 9 patients (37.5%) and CD grade III in 1 (4.2%). The posterior approach group showed the highest rate of complications (P = 0.021). Patients managed using a combined approach showed a larger cyst size (P < 0.001), longer operation times (P < 0.001), and a greater likelihood of tumor level above the coccyx (P = 0.002) compared to other approaches. The tumors of 2 male patients were malignant: 1 was a neuroendocrine tumor treated with radiotherapy, while the other was a closely followed adenocarcinoma. Median follow-up was 12 months (range, 1–66 months) with no recurrence. CONCLUSION: Tailgut cysts are uncommon but can cause perineal or pelvic pain. Complete surgical excision via an appropriate approach according to tumor size, location, and correlation with adjacent pelvic floor muscles is the key treatment.

Tailgut cyst: An uncommonly diagnosed common entity - A case report and review of literature.

Tailgut cysts (TGC) though relatively common are rarely diagnosed and documented. Most of the times, they are misdiagnosed and mismanaged. When malignancy develops in TGC it is rarely attributed to it as it is undiagnosed earlier and later on there may not be any evidence left behind. We report one such case which was diagnosed though not preoperatively. Review of literature reveals only few such cases after the initial description by Hjermstad and Helwig in 1988. Surprisingly most of the reports especially the larger case series are by radiologists. Surgeons and pathologists have contributed very few cases. This case report is aimed at increasing the awareness about this entity so that it will be suspected, investigated properly and treated before development of complications like recurrent fistulae, ischioanal abscesses which increase the morbidity and life threatening complications like malignant change.