Journal of Indian Association of Pediatric Surgeons
Journal of Indian Association of Pediatric Surgeons
                                                   Official journal of the Indian Association of Pediatric Surgeons                           
Year : 2020  |  Volume : 25  |  Issue : 1  |  Page : 15--21

Sacrococcygeal teratoma: Clinical characteristics, management, and long-term outcomes in a prospective study from a Tertiary Care Center

Devendra Kumar Yadav1, Samir Kant Acharya2, Deepak Bagga2, Vishesh Jain1, Anjan Dhua1, Prabudh Goel1,  
1 Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi, India
2 Department of Pediatric Surgery, Vardhman Mahavir Medical College and Associated Safdarjang Hospital, New Delhi, India

Correspondence Address:
Dr. Prabudh Goel
Room No. 4002, 4th Floor, Teaching Block, Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi - 110 029


Introduction: The study focuses on the clinical presentation, management, and outcomes (both short term and long term) in patients with sacrococcygeal teratoma managed over a decade in a tertiary care center. Materials and Methods: This is a prospective study on children with sacrococcygeal teratoma over 12 years data collected included antenatal diagnosis, mode of delivery, age at diagnosis, clinical presentation, physical extent of mass (including Altman classification), levels of alpha-fetoprotein, surgical approach, histopathology, clinical outcome, recurrence and long-term results including bladder-bowel dysfunction and neurological impairment. Functional results were evaluated clinically and radiologically. Results: During the study, 41 patients (male to female ratio of 1:3.1) with a median age of 36 days (1 day–11.6 years) with sacrococcygeal teratoma were managed at our center. The mean follow-up duration was 54 months (range 19–110 months). Nearly, two-thirds of the tumors were either Altman Type 1 or 2. Yolk sac tumor was present in 8 (19.5%) patients, while the rest has either mature or immature teratoma. Tumors were removed through a posterior sagittal or a chevron incision. In seven patients, abdominosacral approach was necessary. Eight patients with malignant disease received chemotherapy (neoadjuvant in 5). Overall survival was 95% at a mean follow-up of 54 months. Among the late complications, three patients had a local recurrence of tumor, and urinary dribbling was present in three patients. Conclusions: Teratomas are the most common germ cell tumors of the sacrococcygeal region. Most of the tumors are benign, and the incidence of malignancy increases with age. The evaluation of malignancy is, therefore, necessary in these children. Excellent survival of 95% was achieved in this series. Morbidity due to associated malformation, disease recurrence, and treatment may persist in these patients; hence, proper follow-up is needed.

How to cite this article:
Yadav DK, Acharya SK, Bagga D, Jain V, Dhua A, Goel P. Sacrococcygeal teratoma: Clinical characteristics, management, and long-term outcomes in a prospective study from a Tertiary Care Center.J Indian Assoc Pediatr Surg 2020;25:15-21

How to cite this URL:
Yadav DK, Acharya SK, Bagga D, Jain V, Dhua A, Goel P. Sacrococcygeal teratoma: Clinical characteristics, management, and long-term outcomes in a prospective study from a Tertiary Care Center. J Indian Assoc Pediatr Surg [serial online] 2020 [cited 2021 Sep 28 ];25:15-21
Available from:

Full Text


Germ cell tumors (GCTs) are uncommon in the pediatric age group and account for approximately 3% of cancers in children <15 years of age. They arise from the primordial germ cells which migrate from the yolk sac to the gonads during embryogenesis. Aberrant migration of these cells may result in extragonadal GCTs which are often limited to midline locations; the sacrococcygeal region being the most common site for extragonadal GCTs in children. Sacrococcygeal teratoma may be diagnosed antenatally or later as a neonate, during infancy or early childhood. It could be benign or malignant. While benign lesions may be managed with simple excision of the mass with coccygectomy, the malignant ones need multimodality approach including surgery and cisplatin-based chemotherapy.

Beyond tumor management and survival, these patients are vulnerable to unsightly scars, bladder-bowel dysfunction, and psychological implications in the long term. Hence, a discussion of the results should not be limited to oncologic surveillance. An active search for such complications and early institution of remedial measures is necessary.

There is paucity of literature on the long-term outcomes in sacrococcygeal teratoma, from the developing countries. The current study focuses on the clinical presentation, management, and outcome (both short term and long term) in patients with sacrococcygeal teratoma managed over a decade in a tertiary care center in a third-world country.

 Materials and Methods

This is a prospective study based on infants and children with sacrococcygeal teratoma between July 2003 and June 2015 (12 years) treated under the Department of Pediatric Surgery at the Vardhaman Mahavir Medical College and associated Safdarjung Hospital, New Delhi, India. Data collected included antenatal diagnosis, mode of delivery, age at diagnosis, clinical presentation, physical extent of mass (including Altman classification),[1] levels of alpha fetoprotein (AFP), surgical approach, histopathology, clinical outcome, recurrence, and long-term results including bladder-bowel dysfunction and neurological impairment.

The diagnosis was based on the clinical suspicion subject to radiological confirmation (ultrasonography with or without contrast-enhanced computed tomography (CT). The management protocol included upfront resection for tumors with age-appropriate AFP levels. Metastatic workup was done for children with raised AFP. Neoadjuvant chemotherapy with two cycles of cisplatin, etoposide, and bleomycin (PEB) (cisplatin at 35 mg/m2/day on days 1–3, etoposide at 100 mg/m2/day on days 1–3 and bleomycin at10 units/m2/day on days 1–3; the chemotherapy cycle was repeated after 21 days) was administered to those not fit for upfront resection. Those with un-resectable tumors or persistent chest involvement post two cycles PEB were administered two more cycles.

Surgical excision was attempted by local (inverted V-shaped or Chevron or posterior sagittal incision) or abdominosacral approach. Abdominosacral approach was reserved for lesions which could be palpated per abdomen. Sacral route with posterior sagittal incision[2] was preferred for tumors with size <5 cm and located more in the midline. Sacral route with inverted V-shaped or Chevron incision was used for larger or eccentrically located masses. Adjuvant chemotherapy (two cycles of PEB for those who had received two cycles PEB before surgery and two cycles of Cisplatin and Etoposide for those who had received four cycles PEB before surgery) was initiated 2 weeks postsurgery.

The follow-up was governed by clinical examination, radiological evaluation, and AFP levels. AFP levels were repeated monthly (in cases with malignancy) or 3 monthly for 6 months followed by yearly for 3-years. Follow-up radiological evaluation with alternate ultrasonography or CT was done at 3 monthly (for 1 year) followed by 6 months' intervals. Cosmetic and functional results were recorded at each follow-up. Functional results were evaluated clinically and radiologically (ultrasonography of kidney, ureter, and bladder with postvoid residue).


Patient demographics

During the study, 41 patients with sacrococcygeal teratoma were managed at our center. There were 31 girls and 10 boys with male to female ratio of 1:3.1 [Table 1]. The median age at presentation was 36 days (range 1 day–11.6 years). It was observed that 21 children presented in the neonatal period (mean 17.6 days, range 1–29 days) [Figure 1]a, 12 children presented in the 1st year of life beyond the neonatal period (mean 81 days, range 32–359 days), and 8 children presented beyond the age of 1 year (mean 5.2 years, median 4 years, range 1.5–11.6 years).{Table 1}{Figure 1}

The mean follow-up duration was 54 months (range 19–110 months).

Maternal demographics

Mean maternal age at the time of childbirth was 27 years (19–33 years). The mean gravidity and parity were 3.1 (range 1–5) and 2.3 (0–6), respectively. History of antenatal diagnosis was available in 7 of 35; the remaining 6 patients were not sure of the antenatal status. All 7 patients in the antenatal diagnosis group presented early; 5 in the neonatal age and the other 2 shortly after. None of these patients had been subjected to any fetal intervention.

Mode of delivery was vaginal in 31 of 39 patients (data for 2 patients not available in records) and cesarean section was done in 8 (indifferent indications n = 6 of 8).

Clinical presentation

All except 7 patients presented with an external sacral mass (82.9%). The concomitant mass palpable per abdomen was present in 7 patients (17.1%). Urinary dribbling was the sole presenting feature (with no external mass) in 1 patient and was associated with an external mass in 4 patients (urinary dribbling: 12.2%). Two patients presented with constipation (4.9%) and 1 patient presented with mucin discharge from a sinus hidden within the anal corrugations (2.4%) [Figure 1]b with inset].

These patients were substratified into subtypes based on the classification proposed by Altman:

Altman 1 – n = 16/41 (39%), Altman 2 – 10/41 (24.4%), Altman 3 – 7/41 (17.1%), and Altman 4 – 8/41 (19.5%).

Of the 7 patients with a tumor palpable per abdomen, 2 patients were graded Altman 3 tumor and 5 patients Altman 4.

Associated anomalies were identified in 7 patients (17.1%). These included bilateral club foot (n = 1/7), hydrocephalus (n = 1/7), high anorectal malformation (n = 1/7), hydronephrosis (n = 2/7: unilateral = 1, bilateral = 1), spina bifida (n = 2/7), cleft lip (n = 1/7), and atrial septal defect (n = 2/7).


Serum AFP levels were evaluated in all patients. The values were elevated in 8 of 41 (19.5%) patients (range 2800–157,000 ng/ml) and normal in 33 of 41 (80.5%) patients. Serum AFP was appropriate for age (considered normal) in all patients <1 month of age, elevated in 3 of 12 (25%) patients in the age group of 1–12 months and elevated in 5 of 8 (62.5%) patients more than 1 year of age at presentation.

The eight patients with raised serum AFP were worked up for metastasis; pulmonary metastasis was detected in two patients. First patient with metastatic lung secondaries was a boy of 4.2 years with one lesion each in left upper lobe and lingula. The second patient was also a boy of 3.8 years with one lesion in the left upper lobe. No intra-abdominal secondaries were detected.


Neoadjuvant chemotherapy (2 cycles of PEB) was administered to 5 of 8 patients with raised serum AFP who were considered unfit for upfront resection in view of massive tumor size (n = 3) and chest metastasis (n = 2). Resection was possible upfront in the remaining 3 patients. All the patients in this group were administered adjuvant chemotherapy postresection (total four cycles PEB including neoadjuvant chemotherapy). Hence, upfront resection was undertaken in all patients with normal and 3 patients with raised serum APF (87.8%).

There was no perioperative mortality in our series.

Surgical approach

Of all the patients, 4/41 (9.8%, all Altman 1) had a small, centrally located tumor (<5 cm) and could be completely removed by posterior sagittal incision, 30/41 (73.2%, Altman 1: n = 12, Altman 2: n = 10, Altman 3: n = 5, and Altman 4: n = 3) were operated by posterior sacral approach (Inverted V-shaped or Chevron incision) [Figure 1]c and 7/41 (17%, Altman 3: n = 2, and Altman 4: n = 5) patients were operated by combined abdominosacral approach.

Histopathological diagnosis

The histopathology was consistent with mature teratoma in 28/41 (68.3%), immature teratoma in 5/41 (12.2%), and yolk sac tumor in 8/41 (19.5%) patients. Mature teratoma was more prevalent in younger children [Table 2]: 19/21 children under 1 month of age, 7/12 children more than 1 month but younger than 1 year, and 2/8 children over 1 year of age. Immature teratoma was found in 2/21 neonates, 2/12 infants excluding neonates and 1 child more than 1-year. All patients with mature and immature teratoma had a normal serum AFP preoperatively. All patients with yolk sac histopathology had elevated serum AFP. In this sub-group, there were no neonates, 3/12 (25%) were infants and 5/8 (62.5%) were more than 1-year of age.{Table 2}

Early complications included wound infection (n = 5; 12.2%), superficial wound dehiscence (n = 2; 4.9%), complete dehiscence (n = 1; 2.4%), copious or prolonged serosanguinous drain output (n = 1; 2.4%; settled spontaneously on the 20th day), and urinary infection (n = 1; 2.4%). The patient with complete wound dehiscence required a diverting sigmoid colostomy. In the early follow-up, urinary dribbling or poor stream was observed in 5 patients (5/41; 12.2%). Fecal soiling was observed in 3 patients (7.3%). There was no incidence of rectal injury in our series.

Late complications included unsightly scar of secondary healing (n = 3; 7.2%), keloid (n = 1; 2.4%), and persistent urinary dribbling (n = 3; 7.2%). None of the patients had fecal incontinence or gait abnormalities.

Recurrence of the tumor was observed in 3/41 patients (7.2%). The histopathology of the cases with recurrence was immature teratoma (n = 1) and yolk sac tumor (n = 2).

The patient with immature teratoma presented (at 299 days) with a local mass which could be palpated per abdomen (Altman 3). Tumor excision with coccygectomy was done by combined abdominosacral approach. Local recurrence at 3 months' follow-up was suspected upon palpation of an abnormal mass on per-rectal examination which was confirmed by CT. His serum AFP then was 10 ng/ml. The recurrence was excised completely. The histopathology of the recurrent mass was also immature teratoma. Follow-up at 45 months' postsecond surgery was satisfactory.

The other two patients with recurrence were first operated at the age of 465 and 759 days, respectively. Both these patients had raised serum AFP at initial presentation and yolk sac components upon histopathology. The first patient had recurrence at 1 month after surgery. He presented for a local swelling, and the serum AFP was >1000 ng/ml. The other patient with recurrence was detected on routine work-up at 3 months' follow-up. Serum AFP was 3400 ng/ml, and there was a presacral mass. Both these patients were started on ifosfamide, carboplatin, and etoposide regime; both these patients expired within 2 months due to complications of chemotherapy.


Overall survival was 39 of 41 (95.1%) at a mean follow-up of 54 months (range 19–110 months). Survival stratified on the basis of nature of disease: benign disease – 33 of 33 (100%) and malignant disease – 6 of 8 (75%). Survival stratified on basis of age at presentation: <1 month: 21 of 21 (100%), more than 1 month but <1 year: 12 of 12 (100%), and more than 1 year: 6 of 8 (75%).


Sacrococcygeal teratomas are the most common of all the GCTs in pediatric age group that originate from the totipotent cells from Hansen's node or primitive germ cells.[3] The reported incidence is approximately 1 in 40,000 live births with a male to female ratio of 1:3–1:4.[4] The male to female ratio in our series is 1:3.1 which is like the rate quoted in literature. The incidence of associated congenital anomalies in our series (17.1%) is also similar to that reported in literature (18%).[1],[5] However, there is a variation of spectrum with hydronephrosis, spina bifida and atrial septal defect being more common in our series. The most commonly reported anomalies in literature are anogenital[6] which we encountered in one patient only. Lahdenne et al., however, reported the incidence of vertebral abnormalities as 80%.[7]

History of antenatal diagnosis was available in 7/41 patients; none of these patients had any significant perinatal complications. A literature-dive revealed that the cases with antenatal diagnosis are at a high risk of perinatal complications and fetal death from high output cardiac failure.[8],[9] Only 2 of these 7 patients underwent cesarean section for indications related to tumor size. A clear majority of the patients included in this series belong to the resource-challenged population who are struggling for the basic necessities of life. However, the importance of antenatal diagnosis in cases with sacrococcygeal teratoma cannot be underscored. The sudden arrest of an otherwise uncomplicated vaginal delivery may necessitate urgent cesarean section. Besides tumor size, placentomegaly, fetal hydrops, and cardiac failure due to arteriovenous shunting may complicate the situation further. It has been suggested in literature that tumors <5 cm in diameter may be handled by vaginal delivery; caesarean section should be preferred for larger tumors. In our cohort, there were at least five patients who were delivered vaginally and presented promptly in whom the tumor size was more than 5 cm (5.2, 5.7, 6.1, 6.3, and 8.1 cm, respectively). Besides labor dystocia, antenatal diagnosis with the assessment of tumor volume to fetal weight ratio is known to have a bearing on prognosis with a reported mortality of 30%–50% in cases diagnosed antenatally.[10]

Two cases in our series had an atypical presentation. One of them was a boy of 2.4 months who presented with a sticky, mucinous discharge from the anus. On clinical examination, there was a discharging sinus at 12 o' clock position hidden within the anal corrugations which was communicating with the central cavity within the tumor. The other patient with atypical presentation was a 6-month-old girl with urinary dribbling as the only complaint. A per-rectal examination was performed to rule out a fecaloma, and a mass posterior to rectum was identified. A literature search on PubMed and Google unearthed several reports wherein sacrococcygeal teratomas have been mistaken for lesions such as hemangiomas,[11] meningomyeloceles,[12],[13] vertebral disc prolapse,[12] abscesses,[12],[14] fecal or perianal fistula,[12] cloaca, and fistula-in-ano or inguinal lymphadenitis.[12] The vice-versa is also true with lesions such as extraspinal sacrococcygeal ependymoma,[15] genitourinary plexiform neurofibroma[16] and congenital infantile fibrosarcoma[17] masquerading as sacrococcygeal teratoma.

The patients have been stratified as per the system suggested by Altman. There were three surgical approaches: posterior-sagittal, posterior sacral (Inverted V-shaped or Chevron incision) and combined abdominosacral. The posterior-sacral approach with the Inverted V-shaped or Chevron incision which was applicable over a wide range of tumor morphology. The Altman system does not correlate with the choice of surgical approach nor can it be used to predict the same. Furthermore, the Altman grading becomes irrelevant in cases who are administered neo-adjuvant chemotherapy. It was further observed in our cohort, that the surgical approach was best predicted based on tumor size at the time of surgery, location of tumor, and relation to vital structures. The posterior-sagittal incision and approach causes less disfigurement, preserves the normal-looking median-raphe and is more cosmetic as compared to the Inverted V-shaped or Chevron incision in the posterior-sacral approach.[2] However, this is suitable for smaller tumors (<5 cm) which are predominantly extrapelvic or have a shallow pelvic extension, not adherent to any vascular structure and located centrally. The muscles of the pelvic floor are better appreciated making the surgery and repair more convenient. However, the case selection for this approach must be guarded strictly by the predefined criteria to avoid any surgical trouble.

The posterior sacral approach through the Inverted V-shaped or Chevron incision has been time-tested and provides an excellent exposure to resect local as well as pelvic masses. However, this approach has limited utility for handling tumors extending beyond the sacral promontory, leaves an unsightly tumor scar and may result in posterior displacement of anus giving a pulled-up appearance.[18]

The combined abdominosacral approach was considered suitable for tumors which were extending beyond the sacral promontory at the time of surgery and could be palpated per-abdomen. In one case with preoperative Altman IV mass and raised AFP, after completion of three courses of chemotherapy, the tumor had shrunk to a small size, 6 cm × 4.9 cm which was not palpable per abdomen but the mass was adhered to bilateral internal iliac arteries. Consequently, the surgery was started by the abdominal approach for clean and safe dissection of the tumor mass away from the major vessels. The tumor was dissected as low down as possible. The distal dissection and coccygectomy were accomplished by the posterior-sagittal approach.

On histopathology, most of the neonatal tumors are mature or immature teratomas.[19] We have observed the same trend in our series. All 21 neonates had either mature (n = 19) or immature teratoma (n = 2). Recurrence is reported in literature in 10%–20% of initially benign tumors and half of these are malignant.[4] In our series, recurrence was observed in 1 of 33 (3.03%) in the benign subgroup (mature and immature teratomas); the initial histopathology was immature and so was the histopathology of the recurrent mass. In our series, yolk sac histopathology was more common in cases (62.5% cases) presenting after 1 year of age. In the American Academy of Pediatrics survey, the incidence of malignancy was 7%–10% in patients operated on at the age of <2 months but 48%–67% if they were treated after 2 months of age.[1] However, in the series by Niramis et al., the incidence of malignancy was only 2.4% in patients who underwent surgery at the age of <1 year and 73.3% in the patients operated on after 1 year of age.[20]

The most frequent complication in the immediate postoperative period is wound infection or dehiscence; this may be related to the proximity to the anus. The rate of wound dehiscence in our series was 7.3% although wound dehiscence rates as high as 90% have been reported in literature.[21] Modifications such as bowel preparation in the preoperative period have been claimed to be beneficial.[22]

Urologic and anorectal dysfunction after surgery for sacrococcygeal teratomas have been reported with a variable incidence. Location of tumor, local invasion, extent of resection, compression injury, and surgical complications may have a decisive role to play. Urological complications are reported more widely than anorectal dysfunction. Partridge et al. have reported urological complications in 33% of patients and anorectal dysfunction in 29% of patients diagnosed by clinical examination, radiological imaging, and standardized follow-up.[23] Ozkan et al. have reported neurogenic bladder in more than three-fourth of the patients[24] after surgery. In our series, we have encountered significantly lower rates of such complications. However, our patient cohort is small, and the data are based on the findings of patient-reported symptoms and voiding behavior, clinical examination, and sonography with the assessment of postvoid residue. Urodynamic evaluation was not performed.

The natural biology of the disease and its anatomic location mandates follow-up in the long-term for other functional sequelae as well such as gait anomalies, sexual function or dysfunction (anatomic and psychological), self-perceived body image and psyche including self-confidence and self-acceptance. It is a general observation in the developing world that despite all counseling and advise, lack of regular follow-up is limiting the availability of data on long-term results. This may be related to ignorance out of illiteracy, excessive working hours to earn bread, and lack of alternative support system.


Teratomas are the most common GCTs of the sacrococcygeal region. Associated anomalies are not uncommon and should be sought for and treated in their merit. Atypical presentation may also be seen in sacrococcygeal teratomas. The initial Altmann grading was not useful for deciding the surgical approach in these cases. There was no procedure-related mortality.

A close follow-up with malignant tumors for recurrence and distant metastasis with serial AFP monitoring and appropriate radiological imaging should be done. Concomitant surveillance on urologic and anorectal dysfunction is also essential.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Altman RP, Randolph JG, Lilly JR. Sacrococcygeal teratoma: American Academy of Pediatrics surgical section survey-1973. J Pediatr Surg 1974;9:389-98.
2Jan IA, Khan EA, Yasmeen N, Orakzai H, Saeed J. Posterior sagittal approach for resection of sacrococcygeal teratomas. Pediatr Surg Int 2011;27:545-8.
3Hirose S, Farmer DL. Fetal surgery for sacrococcygeal teratoma. Clin Perinatol 2003;30:493-506.
4Schropp KP, Lobe TE, Rao B, Mutabagani K, Kay GA, Gilchrist BF, et al. Sacrococcygeal teratoma: The experience of four decades. J Pediatr Surg 1992;27:1075-8.
5Ein SH, Adeyemi SD, Mancer K. Benign sacrococcygeal teratomas in infants and children: A 25 year review. Ann Surg 1980;191:382-4.
6Tuladhar R, Patole SK, Whitehall JS. Sacrococcygeal teratoma in the perinatal period. Postgrad Med J 2000;76:754-9.
7Lahdenne P, Heikinheimo M, Jääskeläinen J, Merikanto J, Heikkilä J, Siimes MA. Vertebral abnormalities associated with congenital sacrococcygeal teratomas. J Pediatr Orthop 1991;11:603-7.
8Hedrick HL, Flake AW, Crombleholme TM, Howell LJ, Johnson MP, Wilson RD, et al. Sacrococcygeal teratoma: Prenatal assessment, fetal intervention, and outcome. J Pediatr Surg 2004;39:430-8.
9Bond SJ, Harrison MR, Schmidt KG, Silverman NH, Flake AW, Slotnick RN. Death due to high-output cardiac failure in fetal sacrococcygeal teratoma. J Pediatr Surg 1990;25:1287-91.
10Akinkuotu AC, Coleman A, Shue E, Sheikh F, Hirose S, Lim FY, et al. Predictors of poor prognosis in prenatally diagnosed sacrococcygeal teratoma: A multiinstitutional review. J Pediatr Surg 2015;50:771-4.
11Mullen M, Rabban J, Frieden IJ. Sacrococcygeal teratoma masquerading as congenital hemangioma. Pediatr Dermatol 2013;30:112-6.
12Jan IA, Hazratullah, Ishaque N, Haq A, Gondal M, Sharif A, et al. Unusual presentation of sacrococcygeal teratomas in pediatric patients. Saudi J Health Sci 2012;1:30-4.
13Sugitani M, Morokuma S, Hidaka N, Kinoshita Y, Taguchi T, Tsukimori K, et al. Three-dimensional power Doppler sonography in the diagnosis of a cystic sacrococcygeal teratoma mimicking a meningomyelocele: A case report. J Clin Ultrasound 2009;37:410-3.
14Khalil BA, Aziz A, Kapur P, Humphrey G, Morabito A, Bruce J. Long-term outcomes of surgery for malignant sacrococcygeal teratoma: 20-year experience of a regional UK centre. Pediatr Surg Int 2009;25:247-50.
15Amin R, Berdan E, Knipstein J, Jarzembowski J, Siddiqui S. Extraspinal sacrococcygeal ependymoma masquerading as sacrococcygeal teratoma in the pediatric patient. Pediatr Surg Int 2018;34:109-12.
16Nasir AA, Abdur-Rahman LO, Ibrahim KO, Adegoke MA, Afolabi JK, Adeniran JO. Genitourinary plexiform neurofibroma mimicking sacrococcygeal teratoma. J Surg Tech Case Rep 2012;4:50-2.
17Al-Salem AH. Congenital-infantile fibrosarcoma masquerading as sacrococcygeal teratoma. J Pediatr Surg 2011;46:2177-80.
18Abou Zeid AA, Mohamed MH, Dahab MM, Gad Allah MA, Zaki AM. Sacrococcygeal teratoma excision: A vertical rather than transverse wound closure. Ann Pediatr Surg 2017;13:207-12.
19Rescorla FJ. Pediatric germ cell tumors. Semin Pediatr Surg 2012;21:51-60.
20Niramis R, Anuntkosol M, Buranakitjaroen V, Tongsin A, Mahatharadol V, Poocharoen W, et al. Long-term outcomes of sacrococcygeal germ cell tumors in infancy and childhood. Surg Res Pract 2015;2015:398549.
21Amoah M, Boateng N, Abantanga FA. Sacrococcygeal teratoma: A 4-year experience at komfoanokye teaching hospital. Postgrad Med J Ghana 2012;1:15-9.
22Villamil V, Girón Vallejo O, Fernández-Ibieta M, Sánchez Sánchez Á, Reyes Ríos PY, Martínez Castaño I, et al. Functional and aesthetic evaluation of sacrococcygeal teratomas. Not everything ends with surgery. An Pediatr (Barc) 2018;88:39-46.
23Partridge EA, Canning D, Long C, Peranteau WH, Hedrick HL, Adzick NS, et al. Urologic and anorectal complications of sacrococcygeal teratomas: Prenatal and postnatal predictors. J Pediatr Surg 2014;49:139-42.
24Ozkan KU, Bauer SB, Khoshbin S, Borer JG. Neurogenic bladder dysfunction after sacrococcygeal teratoma resection. J Urol 2006;175:292-6.