1. Introduction

Sacrococcygeal teratoma (SCT) is a relatively rare solid neonatal tumor and typically requires early surgical treatment. Its incidence ranges from 1 in 30,000 to 40,000 live births ¹, and it is more commonly diagnosed in females than in males (female:male = 4:1)². Despite its rarity, the histology, progression, treatment, and oncological outcomes of SCT are well standardized ³.

Historically, SCT was often identified at or around birth. However, recent advancements in prenatal imaging—now effective in more than 50% of cases—have enabled earlier diagnosis and more structured perinatal and surgical planning ^4,5. These imaging modalities, particularly high-resolution ultrasonography and fetal magnetic resonance imaging (MRI), allow clinicians to evaluate tumor size, vascularization, and anatomical relationships in utero, offering a comprehensive assessment before birth. This shift allows not only earlier detection but also more timely neonatal and surgical management ⁶, potentially resulting in better functional outcomes. In selected high-risk cases, particularly when severe fetal hemodynamic compromise develops due to arteriovenous shunting from the tumor, prenatal interventions such as ultrasound-guided vascular ablation of the feeding vessels (including the median sacral artery) have been described, aiming to reduce cardiac strain and improve perinatal prognosis ⁷. Although these interventions remain experimental in many centers, their use highlights the importance of individualized prenatal risk assessment and the potential for in utero therapies to modify disease course. Additionally, since these interventions are highly specialized and currently limited to selected centers, their availability further underscores the need for centralized multidisciplinary care, as prenatal diagnosis can guide postnatal management and facilitate access to advanced therapeutic options during pregnancy.

Sacrococcygeal teratomas are commonly classified according to the anatomical classification proposed by Altman et al.,⁸ which categorizes tumors into four types (I–IV) based on the relative external and intrapelvic or internal extent of the lesion; type I lesions are predominantly external, whereas type IV lesions are entirely presacral or internal. The vast majority of SCTs are histologically mature and, therefore, benign ⁹. Nevertheless, immature or malignant histology, though less common, has been associated with poorer prognosis and may require additional adjuvant therapy. Regardless of their histological characteristics, due to their mass effect and high vascularization, these tumors can lead to gastrointestinal, urological, and cardiac complications during both fetal and neonatal life ¹⁰.

Sacrococcygeal teratoma treatment typically involves surgical excision of the tumor together with the coccyx to reduce the risk of recurrence and malignant transformation of residual tissue ¹¹. Due to its close connection with the pelvic floor, as well as surrounding parenchymal and nervous structures, surgery carries the risk of long-term sequelae affecting multiple organs ¹². Postoperative outcomes are increasingly recognized as a critical component of overall prognosis, emphasizing the need for careful surgical planning and follow-up.

Mid- to long-term functional outcomes, particularly regarding bowel and urological functions, have been reported in the literature. Gastrointestinal and urinary impairment have historically been attributed to abdomino-pelvic anatomical disruption caused by the tumor growth and the invasive surgical management required for tumor excision ¹³.

Similarly, predictive factors for worse urological outcomes have been proposed. Several authors reported on the association between urinary impairment and large tumors (> 9–10 cm in maximum diameter) ^10,14, higher Altman classification ^2,15, and obstructive fetal urologic pathophysiology ¹⁵. However, these predictors remain inconsistently validated across studies, with heterogeneity in both assessment methods and follow-up duration, highlighting the need for further investigation.

Therefore, our study aims to assess functional outcomes in prenatally diagnosed SCT and to assess whether previously reported predictive factors are associated with urological comorbidities of SCT patients.

2. Methodology

In this retrospective study, we analyzed the medical records of all patients who had a confirmed diagnosis of SCT established during the prenatal period and subsequently underwent surgical treatment at our tertiary referral center. Only cases identified through prenatal imaging modalities were included, covering the period between 2010 and 2021. According to our internal protocol, once SCT is suspected at fetal ultrasound, the patient is enrolled in a multidisciplinary management and follow-up program, involving fetal medicine specialists, surgeons, urologists, neurosurgeons, and oncologists. For the purpose of this study, a minimum follow-up period of three years was required to ensure that all patients had reached the age for toilet training, thereby allowing the identification of potential urological symptoms. Baseline characteristics, perioperative details, histological findings, and clinical outcomes were retrospectively collected.

2.1. Ethical considerations                                                                                            

This was an observational retrospective study based on standard clinical practice. All procedures performed, including follow-up evaluations, were part of routine care, and no interventions outside standard protocols were undertaken. Prior to data collection, all participants or their legal guardians provided written informed consent for the anonymous use of clinical data for research purposes. The local ethics committee was notified of the study and approved its conduct. The study was conducted in accordance with the principles of the Declaration of Helsinki.

2.2. Statistical analysis

Descriptive statistics were applied to summarize the overall cohort. Continuous variables are presented as median (interquartile range [IQR]) or mean (standard deviation [SD]), and categorical variables as counts and percentages. Missing data were handled using a complete-case approach. For all variables included in the analyses (baseline characteristics, perioperative parameters, histology, and clinical outcomes), data were available for all included patients. Variables such as standardized urodynamic assessments, detailed tumor volume measurements, and other advanced functional or imaging parameters were not routinely collected during the early study period and were therefore unavailable for the entire cohort; these variables were not included in the statistical analyses. Given the small sample size and the absence of partial missingness within the analyzed variables, no imputation methods were applied.

Correlation analyses using Spearman’s coefficient were performed to assess associations between previously proposed predictive factors for poor urinary outcomes—namely immature SCT histology, tumor size (>9 cm), Altman type, and surgical approach ^6,14,16—and the occurrence of urinary comorbidities, when sample size allowed. Spearman’s method was chosen as non-normality was assumed, given the limited sample size. Consistent or recurrent prenatal findings correlating with urinary comorbidities were also explored. For variables with insufficient data for statistical testing, results were described narratively. A p-value of less than 0.05 was considered statistically significant for all analyses.

All statistical analyses were conducted using SPSS version 25.0 (SPSS Inc., United States).

3. Results

A total of 30 SCT patients were treated at our center within the study period, with 25 (83.3%) having received a prenatal diagnosis. One patient died at birth, leaving 24 patients who met the inclusion criteria. The female-to-male ratio was 17:7, and the mean gestational age at birth was 36.44 ± 2.5 weeks. Based on tumor size, characteristics, and presence of symptoms, a cesarean section was planned in 12 out of 24 (50%) patients. An additional three cases (12.5%) required urgent cesarean section due to cardiotocographic abnormalities (n = 1) and labor onset (n = 2). The remaining patients underwent vaginal delivery.

The mean birth weight was 3.55 ± 0.66 kg.

Clinical evaluation at birth, together with prenatal imaging, enabled classification according to the Altman classification system for all patients:

• (i) Type I: 16 patients (66.7%); an example of a type I tumor with corresponding prenatal MRI, prenatal ultrasound, and postnatal MRI is shown in Figure 1.
• (ii) Type II: 2 patients (8.3%);
• (iii) Type III: 3 patients (12.5%);
• (iv) Type IV: 3 patients (12.5%);

No cases of Currarino syndrome were identified.

Figure 1. An example of an Altman type I tumor. (A) Prenatal magnetic resonance imaging; (B) Prenatal ultrasound; (C) Postnatal magnetic resonance imaging.

After clinical stabilization and radiological assessment, surgery was planned at a mean age of 5.25 ± 4.1 days. Complete one-stage excision of the mass and coccyx was achieved in 23/24 patients (95.8%). The remaining patient had a large exophytic mass that ruptured during birth, causing bleeding from the sacral arteries. Hemostasis was achieved with partial mass resection at birth, followed by completion of the surgery later the same day after stabilization. A posterior approach was used in 22/24 (91.7%) patients, while two required a combined posterior-anterior approach via laparotomy. Intraoperatively, a Hegar dilator in the rectum was used in all cases to avoid iatrogenic injuries, while intraoperative neuromonitoring was employed when deemed necessary.

The overall mean maximum tumor diameter for the cohort was 10.8 ± 5.03 cm. When stratified by Altman type, mean tumor diameters varied, measuring 12.21 ± 4.93 cm for type I, 11.5 ± 1.50 cm for type II, 5.5 ± 1.47 cm for type III, and 8 ± 5.00 cm for type IV tumors.

Histological diagnosis revealed mature SCT in 12 out of 24 (50%) and immature SCT in the remaining 12 (50%) cases. Maturity rates differed across Altman types: 6 of 16 type I tumors (37.5%) were mature, 1 of 2 type II tumors (50%) demonstrated maturity, all type III tumors (3 of 3, 100%) were mature, and 2 of 3 type IV tumors (66.7%) were mature.

Further details can be found in Table 1.

Postoperative complications were observed in 8 of 24 (33.3%) patients. These included urinary retention requiring temporary clean intermittent catheterization in two patients (8.3%), wound dehiscence in five (20.8%), and wound dehiscence with associated sepsis in one case (4.2%). Patients were discharged after a median hospital stay of 17.5 (IQR 13–28) days and were enrolled in our multidisciplinary follow-up program.

One patient with histologically confirmed mature Altman type I teratoma developed a local recurrence 15.4 months after the initial surgery, requiring a second surgical intervention.

Median follow-up time was 5.59 (IQR 4.81–6.28) years.

In the long term, gastroenterological follow-up revealed functional complications in several patients. Seven out of 24 (29.2%) experienced constipation, and 3 (12.5%) presented with fecal incontinence or soiling.

From a urological standpoint, 3 of the 24 (12.5%) patients developed urological complications: 1 had urinary retention, and 2 experienced urinary incontinence.

One of the incontinent patients also had associated fecal incontinence; both symptoms improved following adjustments to bowel management, including mechanical bowel irrigation and pelvic floor rehabilitation.

The patient with urinary retention was diagnosed with neurogenic bladder and required intermittent catheterization from the immediate postoperative period. Further evaluation with ultrasound, voiding cystourethrogram, and scintigraphy revealed a high-capacity bladder with right vesicoureteral reflux and detrusor overactivity. The reflux resolved over time, but the patient required treatment with oxybutynin and experienced recurrent urinary tract infections (UTIs).

All three patients with urinary comorbidities developed UTIs, leading to an overall UTI incidence of 12.5%. One additional patient experienced an isolated postoperative UTI. No other urological comorbidities were identified in the cohort.

3.1. Potential predictive factors for urological comorbidities

No statistically significant associations were found between urinary comorbidities and previously proposed poor outcome predictors. Specifically, the presence of immature SCT (r_s = −0.37, p = 0.08) and a tumor size larger than 9 cm (r_s = 0.33, p = 0.17) were not statistically significant predictors.

Nevertheless, all three patients with urinary comorbidities had histologically confirmed immature tumors, and two had tumors larger than 9 cm.

Similarly, no clear association was found between Altman type and bladder dysfunction: two patients with urinary issues were classified as Altman type I, and one as type IV. Finally, the surgical approach did not appear to influence urinary outcomes, with two patients having undergone a posterior-only approach and one a combined posterior-anterior approach.

Preoperative tumor volume was not included in the analysis due to incomplete imaging data reports and missing variables. No consistent prenatal imaging abnormalities were observed among the three patients who developed urinary comorbidities.

4. Discussion

With advancements in prenatal diagnostic techniques, our center has established a comprehensive multidisciplinary program for managing sacrococcygeal teratoma (SCT) patients. This program is designed to address the full spectrum of care—from prenatal diagnosis and counseling through surgical treatment to long-term functional follow-up—ensuring continuity and coordination across all stages. In the present study, we describe functional outcomes observed in a cohort of patients managed entirely within this centralized framework. While the retrospective design and absence of a comparator group preclude definitive conclusions regarding causality, the observed patterns provide insight into how coordinated, multidisciplinary care may influence timing of intervention, surveillance, and functional assessment. In particular, surgical treatment was consistently performed early, sometimes immediately after birth in complex or high-risk cases, and functional impairments were identified through systematic follow-up, allowing for prompt, targeted management.

In our cohort, urinary and fecal incontinence were each observed in approximately 12% of patients, while constipation was more prevalent and frequently required therapeutic management. These findings align with previous reports describing bowel dysfunction as one of the most common long-term sequelae following SCT resection ¹⁷. Importantly, the standardized follow-up protocol adopted at our institution, incorporating both gastroenterological and urological evaluations, likely facilitated early recognition of functional disturbances that might otherwise remain underreported, particularly in younger children.

Despite the limited number of patients presenting urinary comorbidities, some notable trends emerged. All symptomatic patients had histologically immature SCT, consistent with prior reports suggesting that immaturity may predispose to poorer functional outcomes ¹⁴.

Similarly, two of the three symptomatic patients had tumors exceeding 9 cm in maximum diameter, corroborating a possible role of lesion size in functional prognosis. Vinit et al.¹⁸ demonstrated a significant association between tumor volume and gastrointestinal impairment at a 3-year follow-up, while this was not observed for urological outcomes. According to their results, neurogenic bladder was found to be associated with preoperative urinary tract dilation on kidney-ureter-bladder ultrasound. Because of the low incidence of urinary comorbidities and the inconsistency of some preoperative data, this association was not tested in our cohort.

Interestingly, contrary to earlier studies such as that by Elgendy et al.,¹⁶ which associated bladder dysfunction with Altman type III–IV tumors, our findings indicated dysfunction in patients predominantly classified as type I.

This finding suggests that tumor stage alone may not reliably capture the mechanisms underlying functional sequelae. Although the tumor’s mass effect (which typically increases from stage I to IV) and surgical manipulation are commonly cited as key contributors to functional sequelae, these relationships may be more complex than previously understood ¹⁹.

Prior studies have reported functional impairments in 20% to 50% of SCT patients ^3,18,20-24. Compared to these, our cohort showed a relatively lower rate of both urinary and bowel incontinence. This discrepancy may reflect differences in cohort composition, as our study had a notably high proportion of stage I tumors (16 out of 24 patients, 66.7%), which are more likely to be detected prenatally and addressed earlier in the disease course. Prenatal diagnosis, in this context, serves as the entry point into centralized care pathways, allowing early multidisciplinary involvement and proactive planning rather than reactive management.

Nevertheless, the distribution of Altman types in our series is consistent with those reported in a multicenter study by Fumino et al.²⁵ and a recent retrospective series from Kadakal et al. ¹⁹, suggesting that our experience may be broadly applicable.

Reported variability in functional outcomes likely stems from differences in study design, follow-up duration, and cohort size across the literature.

Beyond its organizational advantages, centralized care may also contribute to a more refined interpretation of functional outcomes in SCT patients. Concentration of cases within specialized centers allows for standardized definitions of functional impairment, consistent timing of evaluations, and uniform involvement of dedicated subspecialists. This may reduce misclassification of transient versus persistent dysfunction and improve the accuracy of reported outcome rates. In this context, the relatively low prevalence of urinary and bowel incontinence observed in our cohort may not only reflect true clinical benefit, but also the systematic and longitudinal nature of follow-up inherent to centralized care models. Such an effect is difficult to quantify without direct comparison, but should be considered when interpreting outcome variability across published series.

To summarize, while our findings may be partly influenced by the high prevalence of lower-stage tumors, other factors such as centralized care in a specialized, high-volume center and early referral may also play a critical role. A coordinated, multidisciplinary strategy - characterized by early referral, standardized surgical techniques, multidisciplinary perioperative planning, and structured long-term follow-up - may create favorable conditions for early detection and management of functional impairments. Furthermore, early recognition of functional issues during follow-up allows for timely intervention, potentially preventing the progression of dysfunction ^16,26.

Moreover, the incidence of tumor recurrence in our cohort was 4%, which is lower than the 11.8% rate reported by Fumino et al.²⁵ in a large multi-institutional retrospective study, as well as the 11% recurrence rate described in historical cohorts from the Children’s Cancer Group ²⁷. While direct comparisons are limited by differences in study design and follow-up, this finding may reflect the contribution of early diagnosis, careful surgical planning, and coordinated follow-up in improving long-term outcomes.

These observations support the hypothesis that centralized care could promote improved outcomes, a premise that warrants further investigation through prospective, comparative studies.

Despite improved prenatal detection of stage I–II SCT, challenges persist in diagnosing and managing stage III–IV tumors. Improving the prenatal identification of stage III–IV remains important for several reasons: guiding prenatal counselling, optimizing delivery planning, preventing complications like tumor rupture, and ensuring appropriately tailored follow-up ¹⁶.

Nevertheless, prenatal diagnosis plays a pivotal role in contemporary SCT management, independently of the tumor’s stage, providing an opportunity for early identification of the tumor and timely referral to specialized tertiary centers. This early detection allows for coordinated delivery planning, including decisions regarding mode and timing of birth, and enables immediate postnatal surgical assessment, which can minimize perinatal complications such as tumor rupture or hemodynamic compromise. While prenatal imaging in our cohort did not directly predict urinary morbidity, early diagnosis likely facilitated prompt surgical intervention, structured follow-up, and systematic functional assessment within a centralized, multidisciplinary framework. Moreover, prenatal detection allows for anticipatory counseling of families regarding potential surgical risks, functional sequelae, and long-term follow-up needs, promoting informed decision-making. In this context, prenatal diagnosis functions less as a direct prognostic tool and more as a gateway to specialized care pathways, optimizing both immediate management and long-term outcomes. By ensuring that patients are managed from the outset in high-volume, experienced centers, prenatal diagnosis helps maximize the chances for favorable functional and oncological results.

Lastly, ongoing improvements in SCT management underscore the necessity of long-term follow-up programs to monitor symptom progression and functional sequelae through adolescence and adulthood, as routinely done for occult spinal dysraphism ²⁸. Although surgical excision with coccygectomy is the mainstay of treatment, recurrence occurs in up to 15% of cases, particularly in patients with immature histology, large tumors, or incomplete removal of the coccyx. Serial monitoring of alpha-fetoprotein (AFP) is critical for early detection of recurrence or malignant transformation, with imaging reserved for cases of rising AFP or clinical concern. In addition to oncologic surveillance, long-term follow-up enables early identification and management of urogenital, anorectal, and musculoskeletal sequelae that may arise from both the tumor and its treatment, thereby optimizing functional outcomes.

Furthermore, while our study focused primarily on objective functional outcomes, it is essential to recognize the profound psychosocial impact that urinary and bowel dysfunction can have on patients and their families. Urinary incontinence, in particular, has been associated with diminished quality of life, social stigma, and psychological distress in children and adolescents ^6,10,29. By ensuring continuity of care from prenatal diagnosis onward, centralized models may also facilitate earlier psychosocial support and family counseling ³⁰. Future studies incorporating patient-reported outcome measures (PROMs) are essential to fully capture these impacts, enabling more holistic care that addresses both physical and emotional well-being.

Given the limitations inherent in retrospective analyses and small sample sizes, future research should prioritize prospective, multicenter cohort studies to better characterize risk factors for functional impairment in SCT patients. Incorporating standardized urodynamic evaluations and extended follow-up into adolescence and adulthood will be key to understanding the natural history of these sequelae ³¹. Moreover, integrating PROMs systematically will provide valuable insight into patient perspectives and quality of life, guiding more patient-centered clinical decision-making.

5. Strengths and limitations

The main strength of this study lies in its multidisciplinary assessment of functional outcomes in SCT patients, a topic still underrepresented in the literature. The systematic inclusion of urological and gastroenterological evaluations enabled timely identification and management of functional impairments, emphasizing the benefits of structured follow-up. Additionally, standardized assessment protocols and consistent documentation of clinical symptoms allowed for a detailed characterization of functional trajectories over time, contributing valuable insight into the natural history and postoperative course of these patients.

Some limitations should be acknowledged. The relatively small sample size and retrospective nature of the study may limit the strength of statistical associations and the broader applicability of the findings. Additionally, certain preoperative and follow-up data - such as tumor volume, standardized urodynamic assessments, and perioperative surgical parameters - were not consistently available, restricting the depth of possible analyses.

Importantly, the lack of a contemporaneous or historical comparison group limits our ability to directly assess the impact of centralized care on outcomes, and our conclusions should therefore be regarded as descriptive and hypothesis-generating.

6. Conclusion

Outcomes of SCT clearly benefit from timely antenatal diagnosis and multidisciplinary management. Given the risk of urinary impairment related to both the tumor’s mass effect and surgical intervention, standardized urological follow-up is essential for these patients. Our findings suggest that multidisciplinary prenatal and postnatal care provided within a specialized tertiary referral center - with access to coordinated surgical, urological, gastroenterological, and rehabilitative expertise - may contribute substantially to better functional outcomes and lower complication rates.