Search

Case: A 1-year old boy was presented with cauda equina syndrome and progressive loss of motor function in lower limbs. MRI and CT scans revealed a sacrococcygeal teratoma with metastases para-aortically and in L3 producing compression into the epidural space. Despite metastases and a progressive cauda equina, neoadjuvant treatment was given to achieve cytoreduction for neurological recovery and facilitate curative treatment., Conclusion: Malignant sacrococcygeal teratoma with intraspinal infiltration or metastasis requires surgical and adjuvant treatment. If primary neurologic function-sparing surgery makes curative treatment impossible, adequate and quick decompression of neural structures with similar results can be achieved by preoperative chemotherapy, avoiding the local spill of malignant cells., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/C434)., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Introduction:  Sacrococcygeal teratomas (SCTs) are rare tumors occurring in approximately 1 in 35,000 to 40,000 live births. The Altman classification is used to describe SCTs. There are four types, with type 1 predominantly external through to type IV which is a presacral, completely internal mass. As far as the authors are aware, this is the first study to focus on type IV SCT lesions., Materials and Methods:  Using ICD-10-AM (The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification) codes, we identified all patients in the Republic of Ireland with a diagnosis of SCT from 2004 to 2020. The following information was obtained for each patient: gender, time of diagnosis, clinical presentation, method of diagnosis, Altman classification, biomarkers, age at operation, surgical technique, pathology, recurrence, and age at most recent follow-up., Results:  There were 29 patients in total; 23 females (79%) and 6 males (21%). In total, 16 (55%) were diagnosed antenatally, 4 (14%) at less than 1 month, 4 (14%) less than 1 year, 3 (10%) age 2 to 4 years, and 2 (7%) were aged 5 to 12 years. In addition, 22 (76%) were mature teratomas, 2 (7%) immature teratomas, and 5 (17%) were malignant tumors. There were 6 (21%) type I lesions, 9 (30%) type II, 6 (21%) type III, and 8 (28%) type IV lesions., Conclusion:  In Altman's original 1974 study, type IV lesions were present in 10% of cases. As a result, this is the most frequently quoted figure. Type IV lesions were present in 28% of cases in our study. We propose that type IV lesions may be more common than the current literature suggests and consequently a higher index of suspicion of their presence should be entertained., Competing Interests: None declared., (Thieme. All rights reserved.)

Introduction: Sacrococcygeal teratomas (SCT) with malignant histology frequently recur and are treated aggressively, but risk factors and surveillance protocols are less established for mature tumors. In particular, prior studies have not investigated whether microscopic deposits of yolk sac tumor (YST) in otherwise mature teratomas lead to higher recurrence rates., Methods: We reviewed patients with mature SCTs resected at our institution from 2011 to 2021 and analyzed tumor characteristics, treatment, and outcomes., Results: We identified 56 patients with mature SCT, of which 9 (16%) demonstrated microscopic YST. Following surgery, 7/56 (13%) patients developed local recurrence at a mean of 1.2 ± 0.7 years, while no patients developed metastases. Recurrence was more likely in patients with microscopic YST [5/9 (56%) vs. 2/47 (4%), p = 0.021] and positive margins [6/24 (35%) vs. 1/32 (3.1%), p = 0.030]. A solid tumor component tended to increase recurrence risk as well [6/29 (21%) vs. 1/27 (4%), p = 0.053]. Five patients demonstrated malignant recurrence and were all detected by a rising alpha-fetoprotein (AFP), while two patients demonstrated recurrence of mature teratoma and were detected on surveillance magnetic resonance imaging (MRI)., Conclusions: Microscopic foci of YST may increase recurrence risk for patients with mature SCT. Such patients might benefit from closer postoperative surveillance with serial AFP measurements and MRI., (© 2024 Wiley Periodicals LLC.)

Sacrococcygeal teratoma is a congenital tumor of early infancy. Eighty percent are present in the first month of life. It is considered to be an extragonadal germ cell tumor that can be diagnosed in utero. It is considered to be a rare tumor in infancy and childhood. Incidences in girls are more common as compared to boys. Association with other congenital abnormalities of the gastrointestinal system, cardiovascular system, and urological manifestations may be present. Association with spinal dysraphism may be present. A complete systemic evaluation needs to be done before any surgical intervention. We hereby present you a case of a 5-day-old male child, born from a non-consanguineous marriage, who presented to us with a large swelling at the coccygeal region. The mass had a variegated consistency with an ear-like appendage over it with associated hair, bones, and necrotic tissue in it. The patient was evaluated with imaging (MRI) which revealed a heterogeneously enhancing mass at the sacrococcygeal region with mild extension into the pre-sacral space suggesting sacrococcygeal teratoma. After a complete evaluation for congenital abnormal abnormalities of other sites, gross total excision of the mass was performed. The post-operative condition of the baby was uneventful. A biopsy of the mass revealed a mature cystic teratoma. The baby is under follow-up at present., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Tumor recurrence, anorectal and urinary dysfunction, and lower limb dysfunction after surgery are observed in infantile sacrococcygeal teratoma (SCT). In this paper, a multi-institutional retrospective observational study was conducted to clarify the long-term functional prognosis in Japan., Methods: This study was conducted using a paper-based questionnaire distributed to 192 facilities accredited by the Japanese Society of Pediatric Surgeons, covering patients who underwent radical surgery at less than 1 year old and who survived for at least 180 days after birth from 2000 to 2019., Results: A total of 355 patients were included in this analysis. Altman type was I-II in 248 and type III-IV in 107, and the median maximum tumor diameter was 6.1 (range: 0.6-36.0) cm. There were 269 mature teratomas, 69 immature teratomas, and 10 malignant tumors. Total resection was performed in 325, subtotal or partial resection in 27, and surgical complications were noted in 54. The median postoperative follow-up was 6.6 (0.5-21.7) years. Eighty-three patients (23.4 %) had functional sequelae, including 62 (17.5 %) with anorectal dysfunction, 56 (13.0 %) with urinary dysfunction, and 15 (4.2 %) with lower limb motor dysfunction. Recurrence occurred in 42 (11.8 %) at a median age of 16.8 (1.7-145.1) months old. Risk factors for dysfunction included preterm delivery, a large tumor diameter, Altman type III-IV, incomplete resection, and surgical complications. Risk factors for recurrence included immature teratoma or malignancy, incomplete resection, and surgical complications., Conclusions: Postoperative dysfunction was not low at 23.4 %, and 11.8 % of the patients experienced recurrence occurring more than 10 years after surgery, suggesting the need for periodic imaging and tumor markers evaluations in patients with risk factors. It is necessary to establish treatment guidelines for best practice monitoring of the long-term quality of life., Level of Evidence: Level II Retrospective Study., Competing Interests: Conflicts of interest The authors declare there are no conflicts of interest associated with this study., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Surveillance following sacrococcygeal teratoma (SCT) resection varies. The purpose of this study was to describe the clinical characteristics and outcomes of patients undergoing SCT resection and examine current institutional practices to detect recurrence., Methods: A single-institution retrospective review of children who underwent resection of an SCT from January 1, 2010 to December 31, 2020 was performed. Data were summarized and surveillance strategies compared between histopathologic subtypes using nonparametric methods., Results: Thirty six patients (75.0% female) underwent SCT removal at a median age of 8 d. Histopathology revealed 27 mature teratomas (75.0%), eight immature teratomas (22.2%), and one malignant germ cell tumor (2.8%). Median postoperative follow-up was 3.17 y (interquartile range [IQR]: 2.31-4.38 y). Patients had a median of 2.32 clinic visits per year (IQR: 2.00-2.70), alpha-fetoprotein levels were obtained at a median of 2.01 times per year (IQR: 0-1.66), and surveillance imaging was performed at a median of 2.31 times per year (IQR: 0-2.84). Patients with immature teratomas had alpha-fetoprotein laboratories obtained more frequently than patients with mature teratomas (3.10 times/year versus 0.93 times/year, P = 0.001). There was no significant difference in the number of imaging studies obtained between groups. Two patients (5.6%) developed recurrence, which were identified on magnetic resonance imaging at 191 and 104 d postresection, respectively., Conclusions: Postoperative surveillance practices varied widely. Recurrence was noted in a single malignant case in the first year following resection. Multi-institutional studies are needed to determine the optimal surveillance strategy to detect recurrence of SCT., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Sacrococcygeal teratoma is the most common extragonadal germ cell tumor in the pediatric population, and accounts for approximately 70% of all teratomas in childhood. 1 , 2 They present in two distinct phases, with most cases seen in neonates with large predominately exophytic tumors, often detected in utero on prenatal sonography or at birth. A smaller cohort presents in older infants and children with primarily hidden tumors in the pelvis which have a much higher rate of malignancy. The primary surgical objective is complete tumor resection without compromise to critical structures or function. Herein we outline the critical elements of tumor resection and management of sacrococcygeal germ cell tumors with a focus on the technical aspects of this tumor across a range of presentations., (Copyright © 2023. Published by Elsevier Inc.)

Study Objective: To show how advanced pelvic Schwannoma can be safely managed with a laparoscopic approach., Design: Demonstration of the laparoscopic technique with narrated video footage., Setting: Schwannomas are benign tumors that arise from well-differentiated Schwann cells (glial cells) of peripheral nerve sheaths. Schwannomas are nonaggressive, slow-growing, solitary masses with a low rate of malignant transformation and a low risk of recurrence after resection. They rarely occur in the pelvis, with a reported incidence of 1% to 3%. Tumors involving spinal nerve roots commonly present with radicular pain and nerve compression syndromes (Supplemental Video 1-3). This video shows the management of pelvic Schwannoma originating from the left sacral root S1 by a minimally invasive approach., Interventions: Laparoscopic nerve-sparing excision of a pelvic Schwannoma., Conclusion: Historically, pelvic schwannomas have been managed mainly by laparotomy. Here, we demonstrate the feasibility and safety of a large pelvic Schwannoma excision by a minimally invasive approach., (Copyright © 2023 AAGL. Published by Elsevier Inc. All rights reserved.)

Sacrococcygeal teratomas are common tumours in neonates and infants, primarily affecting females. A 35-year-old primigravida presented with a large sacrococcygeal teratoma that was detected during the 30th week of gestation in the fetus. The baby was delivered via elective caesarean section at 36+3 weeks, and surgical excision of the 10x10x5 cm³ mass was performed successfully on the third day of life. Despite a surgical site infection, the patient had a favourable outcome with normal vital signs, bowel, bladder, and lower extremity functions upon discharge. Early diagnosis and prompt management of sacrococcygeal teratoma in newborns is vital for optimal outcomes, providing valuable insights and guidance to medical practitioners., Keywords: anaesthesia; case reports; neonate; teratoma.

Spinal filum terminale pial arteriovenous fistulas (FT PAVFs) are uncommon. Most FT PAVFs are located in the lumbar region; far fewer are located in the sacral region. Due to the rarity of sacral FT PAVFs, the precise surgical dissection and removal of these lesions are challenging. Here, we report an FT PAVF in the sacral region. The patient was a 45-year-old male who suffered from progressive weakness and numbness of the bilateral lower limbs; his symptoms gradually worsened. Digital subtraction angiography (DSA) showed an AVF at the sacral canal at the S3-4 level. Microsurgical treatment with intraoperative DSA was performed, and the FT PAVF was resected. After the operation, the patient gradually recovered. Follow-up magnetic resonance imaging revealed a recession in the dilation of the spinal cord venous plexuses. A literature review was also performed, and a total of 14 FT PAVFs of the sacral region were identified. The patients identified in the literature review had an average age of 58.9 ± 12.9 years, and 92.9% of the patients were male. Spinal cord edema was present in 85.7% of the FT PAVF patients. Regarding treatment, 64.3% of the FT PAVF patients underwent microsurgical resection, 28.6% patients underwent endovascular treatment, and 7.1% patients underwent a hybrid operation; good outcomes were achieved with all three methods. Therefore, FT PAVF of the sacral region is a unique lesion whose angioarchitecture needs to be identified carefully; prompt treatment is necessary, and microsurgery can yield good outcomes.

Teratomas are a subtype of germ cell tumors composed of a variety of somatic tissues derived from more than one of the three germinal layers (ectoderm, endoderm and mesoderm). They can be classified as mature tumors and immature tumors. Teratomas most commonly arise at the sacrococcygeal region and the gonads. The occurrence of a teratoma outside the common gonadal and midline locations is exceptional. This review article lists the reported primary and metastatic malignant teratomas in extragonadal locations and discusses the possible explanation for the atypical location, their treatment and prognosis., (© 2022. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: Sacrococcygeal teratoma (SCT) is a rare congenital tumor originating from a variant of extragonadal germ cell neoplasm. Herein, we present three cases of neonatal SCTs undergoing surgical resection and reconstruction. We also review the literature to discuss the importance of proper perinatal management and timely surgical intervention depending on the tumor type and maturity to prevent malignant transformation and recurrence and ensure functional outcomes., Methods and Results: Three cases of SCT were retrospectively analyzed. All infants underwent complete surgical resection of the SCT and coccygectomy during their neonatal/infancy period, followed by pelvic floor and buttock reconstruction while minimizing buttock contour deformity and undesirable skin scar. Two of the cases were histopathologically diagnosed as predominantly cystic mature teratomas of Altman types I and IV, and the third was a mature teratoma of Altman type II. There were no complications or tumor recurrence during the average follow-up period of 5.3 years., Conclusions: This case-based review highlights the role of multidisciplinary team approaches, including prenatal monitoring, oncologic resection, and adequate reconstruction according to the type of tumor and anomaly. Optimal perinatal evaluation allows promising oncologic and functional outcomes in terms of timely intervention to eliminate tumor recurrence and malignant transformation. Complete oncologic surgical resection of SCTs should also include proper functional preservation strategies, such as the reconstruction of the pelvic floor, cosmetic buttock contouring, and preservation of bladder and bowel sphincter function., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim: Sacrococcygeal teratoma (SCT) is a rare paediatric germ cell tumour (1:40,000). Long-term data regarding urinary tract and bowel function after SCT resection is limited to few studies. A UK Children's Cancer and Leukaemia Group (CCLG) Surgeons multicentre study aimed to critically analyse long-term functional outcomes in patients following resection of SCT., Methods: Nationwide study of UK paediatric surgical oncology centres using a standardised data collection form. All index cases of newborn infants and children <16 years with SCT diagnosis during 2005-2015 were included., Results: 165 SCT patients treated at 14 UK paediatric surgical oncology centres were included. Median age at presentation was 1 day [interquartile range, IQR: 0-25]; median age at surgery was 10 days [IQR: 4-150]. One hundred seventeen (70%) were female and 48 (30%) male. Antenatal diagnosis was made in 44% index cases. Total 59% of patients were Altman Stage I or II lesions. Follow-up data were available in 83% cases. Tumour recurrence occurred in 13 (7%) patients at median age 13 months [IQR: 8.75-30 months]. Fifty-nine (36%) of 165 patients had documented adverse bladder or bowel dysfunction. Twenty-two (37%) cases required urinary clean intermittent catheterisation (CIC) urology health care, with eight patients (14%) needing operative intervention to control management of bowel dysfunction., Conclusion: This UK CCLG study showed 36% of SCT patients develop bladder or bowel dysfunction after primary tumour resection. Functional assessment of bladder and bowel function is mandatory during after-care follow-up of all SCT patients. A multidisciplinary care pathway, with surgeon speciality groups including surgical oncology, paediatric urology and paediatric colorectal specialists, is strongly advised to facilitate 'best practice' monitoring of long-term health and improve patient quality of life (QoL) into adulthood., (© 2022 Wiley Periodicals LLC.)

Sacrococcygeal teratomas (SCT) in adults are extremely rare, and most SCTs are located either mainly outside the pelvis, with a small number of intrapelvic components, or mostly in the pelvis (types III and IV). The etiology of teratomas remains unknown. Most teratomas are benign, and approximately 1 to 2% of teratomas undergo malignant transformation, including squamous cell carcinoma, adenocarcinoma, sarcoma, and other malignancies. Most SCTs grow insidiously, and their symptoms are not easily detected in the early stages. Some cases may only be discovered through physical examination or compression symptoms when the tumor reaches a detectable size. Computed tomography and magnetic resonance imaging have high detection rates for presacral space-occupying lesions and can provide imaging details with guiding significance for the selection of surgical methods. Surgical resection is the preferred treatment option for SCT and can determine the pathological type. Common sacrococcygeal malignancies are mainly immature teratomas and mature teratomas. When the presence of malignant components is confirmed, the treatment model should be adjusted according to pathological type., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

A 6-month-old girl was presented to our hospital due to a presacral mass found 5 months after surgery of sacrococcygeal teratoma. The original tumor was a 63 x 50 mm sized round cyst connecting to the coccyx, observed with computed tomography. The initial operation was performed with en bloc removal of the tumor along with the coccyx in the prone position. During a routine follow up, ultrasonography indicated a possible local recurrence, 5 months after the initial operation. The magnetic resonance imaging revealed a polycystic formation with a diameter of 20 x 11 x 17 mm in the presacral space. The laparoscopic operation was conducted with the patient in the lithotomy and Trendelenburg position. The broad ligament of uterus was fixed to the abdominal skin and the rectum was mobilized to identify the tumor, which was resected laparoscopically. A histopathological examination showed the tumor to be a mature cystic teratoma. We observed her without any additional treatment and no recurrence is seen after 6 months.

Introduction: sacrococcygeal teratoma (TSC) is the most common tumor of the neonatal period. Alphafetoprotein is an important tumor marker and is used in the follow-up period as a marker of malignancy. The complete surgical resection of the tumor associated with coccygectomy is the standard treatment and chemotherapy in different stages are necessary. Follow-up consists of serial exam: tumor markers, imaging searching to possible metastasis sites, in addition to a complete physical examination., Methodology: a descriptive, retrospective, study was carried out by analyzing a chart of 25 patients of two different reference children cancer center; with TSC in the State of Rio de Janeiro from 2004 to 2019. The clinical and epidemiological data collected were described and a comparison was made between these two centers studied., Results: the sociodemographic characteristics found were similar to those described in the medical literature. Data related to treatment and follow-up, such as the use of chemotherapy, use of specific imaging tests, digital rectal examination, and outpatient follow-up, differed between the two centers studied. There was a 25% loss of follow-up., Conclusion: the characteristic of being a non-cancer center can interfere with the full application of the current protocol for the treatment of sacrococcygeal teratoma. The knowledge of the data of the studied cases can allow the optimization of the approach of the patients with this pathology and generate discussions about the integral application of the specific therapeutic protocol in the medical centers that are qualified for such treatment.

Background Neuroblastoma can arise from extra-adrenal sites in the paraspinal sympathetic chain, including the presacral region, where they must be differentiated from an immature or malignant neural lesion arising from a teratoma. Case Report We describe two congenital presacral neuroblastomas. The main clinical differential diagnoses were sacrococcygeal teratoma and meningomyelocele. Pathologically, they lacked teratomatous tissues, lacked germ cell serum markers, were localized without metastases, and were MYCN non-amplified. Both patients have done well without chemotherapy at 18 and 15 months of follow-up. Conclusion Congenital presacral neuroblastoma should be differentiated from teratomatous lesions, and in general have a good prognosis.

Background: Sacrococcygeal teratomas (SCT) are known as rare tumors, but they are the most common tumor in fetuses and newborns. This study aims to present fetal magnetic resonance imaging (MRI) findings of SCT diagnosed prenatally and compare them with that of the prenatal Ultrasound (US) findings., Methods: Eleven patients diagnosed as SCT prenatally by US and further assessed by MRI are included. MRI was performed via a 1.5-T magnet with a body coil. The presence, size, content extension, and compressive effects of each mass were determined and correlated with US findings and with postnatal examinations, including surgery and pathology. As complications, the presence of ascites and skin edema or pleural or pericardial effusion was diagnosed as hydrops. The amniotic fluid index was calculated for the assessment of oligo- or polyhydramnios., Results: US findings are found strongly correlated with MRI findings. An agreement on the extent of each mass was observed in eight patients, disagreement in one fetus was an extension of the tumor within the spinal canal recognized only at MR and assessment of intrapelvic-abdominal extension was superior in MRI. There were n = 6 type I, n = 2 type II, n = 1 type III and, n = 2 type IV tumors. MRI was superior to US for detecting displacement of the colon (n = 3), intrapelvic-intraabdominal extension (n = 1), urinary tract complication (n = 2), and intraspinal extension (n = 1)., Discussion: MRI is found to be superior to US especially in the assessment of intrapelvic and intraspinal extension of the tumor, colonic displacement, and complications.

Objective: To investigate the prenatal diagnosis and prognostic factors of fetal sacrococcygeal teratoma (SCT). Methods: A retrospective analysis was performed on 41 pregnant women who were diagnosed with fetal SCT by prenatal ultrasound at the Women's Hospital, Zhejiang University School of Medicine from January 2014 to September 2021. The prenatal imaging features and pregnancy outcomes, including tumor volume to fetal weight ratio (TFR), proportion of solid tumor, tumor growth rate (TGR), fetal hydrops, placentomegaly and polyhydramnios were analyzed. Receiver operating characteristic (ROC) curve was used to determine the critical values of TFR and TGR for predicting adverse fetal outcomes. Results: (1) Among the 41 pregnant women with fetal SCT, the diagnostic gestational week of ultrasound was (24.2±2.9) weeks (range: 18-28 weeks). Among them, 1 case progressed to fetal hydrops and induced labor at 22 weeks of gestation, 1 case developed intrauterine death and induced labor at 29 weeks of gestation, and 39 pregnancies continued until delivery. Among the 39 cases of continued pregnancy, 1 case underwent cesarean section at 31 weeks of gestation due to malignant polyhydramnios and increased fetal cardiothoracic ratio in the third trimester, 1 case underwent cesarean section at 32 weeks of gestation due to fetal heart failure, and 1 case underwent cesarean section at 32 weeks of gestation due to fetal heart failure and hydrops. The other 36 cases underwent surgical resection of tumor within 3 weeks after birth with good prognosis. (2) TFR>0.12 before 28 weeks of gestation could predict poor fetal prognosis, with a sensitivity of 100.0%, a specificity of 86.1% and an area under curve (AUC) of 0.922 ( P <0.01). Among the fetuses with TFR>0.12, 5/10 had poor prognosis, while the fetuses with TFR≤0.12 all had good prognosis (100%,31/31), and the difference between the two groups was statistically significant ( P <0.001). (3) TGR>48 cm 3 /week could predict poor fetal prognosis with a sensitivity of 100.0%, a specificity of 78.3% and an AUC of 0.880 ( P <0.05). (4) Among the 28 SCT fetuses delivered in our hospital, the incidence rate of poor fetal prognosis was 0 (0/20) in those with solid tumor component<50%, and 5/8 in those with solid tumor component ≥50%, and the difference between the two groups was statistically significant ( P <0.01). The incidence rate of poor fetal prognosis was 2/2 in those with placentomegaly (all with fetal hydrops), and 12% (3/26) in those without placentomegaly. The risk of poor fetal prognosis was 8.67 times higher in those with placentomegaly than those without placentomegaly, and the difference between the two groups was statistically significant ( P <0.05). The incidence rate of poor fetal prognosis in those with polyhydramnios was 3/7, and 10% (2/21) in those without polyhydramnios, but there was no statistically significant difference between the two groups ( P >0.05). Conclusion: TFR combined with solid tumor morphology, TGR, and presence of placentomegaly could predict the adverse pregnancy outcomes of fetal SCT.

Objective: This study aims to characterize the molecular signatures of sacrococcygeal teratomas (SCTs). Methods: Three SCTs were analyzed with whole genome genotyping. RNA sequencing of 10 SCTs dominated by mature, immature and neuroglial elements was analyzed. Expression in SCT-samples with different elements were compared to each other and to a reference group of malignant pediatric tumors. Macrophages, T- and B-lymphocytes were detected by immunohistochemistry. Results : No chromosomal imbalances were detected. SCTs showed overexpression of genes involved in neurosignaling, DNA-binding molecules and pathways of early germ cells. Genes associated with immune effector processes were overexpressed in mature compared to immature SCTs, and immune cell infiltration was found predominantly around mature epithelial elements. Conclusion: The broad repertoire of histological elements in SCTs reflects differences in transcriptional regulation rather than differences in gene copy numbers. A paucity of immune response in immature SCTs may be a factor contributing to their uninhibited growth.

&lt;b&gt;Introduction:&lt;/b&gt; As a rule, the treatment of pilonidal cysts is based on a surgical approach. Surgical treatment depends on the form of the disease and surgeon&apos;s preferences regarding the method. The treatment process does not consider preoperative treatment that would affect the structural components of the skin involved in the pathological process. The results of surgical treatment remain unsatisfactory, leading to a significant number of recurrences and long-term healing of the postoperative wound. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Materials and methods:&lt;/b&gt; Morphological examination of the pieces of skin with altered sacrococcygeal tissues after radical surgical treatment of 46 patients with pilonidal cyst of the sacrococcygeal region was performed, and 46 patients with acne inversa of the intergluteal cleft, groin and scalp were selected. The sex distribution of patients with pilonidal cysts was as follows: 43 (91.3%) male patients, 3 (6.5%) female patients. Among 46 patients with acne inversa and dissecting cellulitis, the distribution was as follows: 32 (69.6%) male patients and 14 (30.4%) female patients. Patients with pilonidal cysts of the sacrococcygeal region underwent surgical treatment according to the developed method of economical median resection using sutures with internal fixation. &lt;/br&gt; &lt;/br&gt; &lt;b&gt; Results:&lt;/b&gt; Considering and comparing the morphological picture observed in the pathomorphological examination of histological specimens in patients with pilonidal cysts, acne inversa, dissecting cellulitis, the similarity of changes in most patients is noteworthy. "Acne inversa" was first described in 1839 by Velpeau, who originally called the disease "hydradenitis suppurativa", believing that inflammatory changes occur in the sweat glands [1-3]. In 1854, surgeon Verneuil described this disease, and later it was named after him. We observed chronic proliferative inflammation in different layers of the dermis and subcutaneous tissue (the main focus is in the subcutaneous tissue, but closely related to the dermis and epidermis). &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Discussions:&lt;/b&gt; Pilonidal cyst of the sacrococcygeal region, especially without hair in the cavity of the cyst, can be considered as a type of acne inversa with appropriate location. We believe that the use of local and systemic retinoids, namely isotretinoin, in the treatment of patients with this disease other than surgery, together with other groups of drugs traditionally used in the treatment of pilonidal cysts, may be promising in the treatment of pilonidal cysts.

Introduction: Neoplastic degeneration is an uncommon but extremely serious complication of pilonidal sinus (PS) disease. We pretend to determine the factors that influence in the prognosis of the neoplastic disease assessing clinical features and histological findings., Materials and Methods: We retrospectively studied the patients diagnosed of malignization of PS in our institution from 2000 to 2019., Results: Seven male patients with a mean age at diagnosis of 64.8 years old were collected. Average time between the initial symptoms of PS disease and the tumor diagnosis was 33.7 years. The patients presenting an ulcerative pattern in the primary tumor showed in all the cases perineural invasion, local deep structures infiltration, and neoplastic dissemination to the regional lymph nodes. All these patients died in an average time of 7 months. On the other hand, patients with exophytic patterns in the primary tumor did not present local invasion or regional nodes affectation. All the cases survive with an average follow-up of 70.5 months., Conclusions: Ulcerated lesions clearly show a worse prognosis than tumors with exophytic morphology. Factors as perineural infiltration, local deep structures infiltration, or regional lymph node involvement dramatically decrease survival rates., (Copyright: © 2022 Permanyer.)

Sacrococcygeal teratomas (SCTs) are rare congenital tumors. With the improvement of diagnostic imaging methods and follow-up protocols in pregnancies, in utero detection of these tumors has increased. Despite these progresses, SCTs may present difficulties in establishing in utero diagnosis and subsequent management. We present two cases of SCT in 18 weeks, respectively 22 weeks pregnancy, diagnosed using ultrasound imaging and pathologically confirmed. Also, the article aims to recapitulate clinicopathological aspects and prognosis of these lesions, following the review of the literature.

Abstract: A 9-year-old girl presented with a slow-growing and painless mass for 7 months in the soft tissue of the sacrococcygeal region. Magnetic resonance imaging revealed a well-circumscribed solid mass located in the subcutaneous soft tissue of the sacrococcygeal area, but not affecting bone structures. The mass was completely removed, and the disorder was diagnosed as myxopapillary ependymoma. In addition, the MYCN gene amplification status of the tumor was evaluated. Extra-axial ependymomas are very rare tumors with a tendency to metastasis, but they are usually regarded as low-grade ependymomas. Long-time surveillance and follow-up are necessary even after complete excision. Besides, we also discuss the diagnosis of primary soft tissue myxopapillary ependymoma., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

This is the first report of an immature sacrococcygeal teratoma with inguinal lymph node metastasis, providing the histologic transformation of an immature teratoma in association with chemotherapy. Incomplete tumor resection with coccygectomy was performed, and the histopathologic diagnosis was a grade 3 immature teratoma. Following the initial surgery, the residual tumors enlarged and the tumors metastasized to the inguinal lymph node, demonstrating immature teratoma without yolk sac tumor components. Although the tumor markers normalized after chemotherapy, the residual tumors had enlarged significantly. Therefore, a complete resection of the residual tumors was performed, and they were found to be mature teratomas., Competing Interests: The authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.

Abstract: During the COVID-19 pandemic, an increasing number of patients have been admitted to the ICU with severe respiratory complications requiring prolonged supine positioning. Recently, many case reports have been published regarding dermatologic manifestations associated with COVID-19. However, there is little information about the clinical features of these manifestations. Pyoderma gangrenosum (PG) is an ulcerative noninfectious inflammatory disease of the skin. In at least 50% of the cases, the etiology is unknown. Nevertheless, PG is associated with many systemic diseases. In this article, the authors report two critically ill patients with COVID-19 who developed sacral ulcers during their recovery in the ICU. These ulcers had an atypical course and were exacerbated by surgical debridements. Accordingly, providers suspected PG, which was confirmed by the clinical evolution of the ulcers and biopsies taken from the wounds. To the best of the authors' knowledge, no previous articles have reported sacral pressure injuries associated with PG in patients with COVID-19. Providers should suspect PG in patients with COVID-19 who develop nonhealing pressure injuries., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Perineural invasion (PNI) as a grossly underreported independent risk predictor in rectal cancer is hard to identify preoperatively. We aim to predict PNI status in rectal cancer using multi-modality radiomics. In total, 396 radiomics features were extracted from T2-weighted images (T2WIs), diffusion-weighted images (DWIs), and portal venous phase of contrast-enhanced CT (CE-CT) respectively of 94 consecutive patients with histologically confirmed rectal cancer. T2WI score, DWI score, and CT score were calculated via the radiomics features selection and optimization. Discrimination, calibration, and clinical benefit ability were used to evaluate the performance of the radiomics scores in both training and testing datasets. CT score and T2WI score were independent risk predictors [CT score, OR (95% CI) = 4.218 (1.070-16.620); T2WI score, OR (95% CI) = 105.721 (3.091-3615.790)]. The concise score which combined CT score and T2WI score, showed the best performance [training dataset, AUC (95% CI) = 0.906 (0.833-0.979); testing dataset, AUC (95% CI) = 0.884 (0.761-1.000)] and good calibration (P > 0.05 in the Hosmer-Lemeshow test for the training and testing datasets). Decision curve analysis showed that the multi-modality radiomics nomogram had a higher clinical net benefit. The multi-modality radiomics score could be used to preoperatively assess PNI status in rectal cancer.

An otherwise healthy eight-year-old girl presented with a mass in the soft tissue of the sacral region. The lesion was diagnosed as a vascular malformation on imaging studies, for which percutaneous sclerotherapy was attempted. The mass continued to grow and a complete resection was performed after four years. The pathological diagnosis was giant cell ependymoma (GCE). GCE is a term used to describe a rare histologic variant of ependymoma characterized by malignancy-like morphologic phenotype and indolent behavior. To the best of our knowledge, this is the first case of extra-axial soft tissue sacral GCE reported in a child., (© 2021 Japanese Society of Neuropathology.)

Our understanding of pilonidal sinus disease (PSD) is based on a paper published 29 years ago by Karydakis. Since then, surgeons have been taught that hair more easily penetrates wet skin, leading to the assumption that sweating promotes PSD. This postulate, however, has never been proven. Thus we used pilocarpine iontophoresis to assess sweating in the glabella sacralis. 100 patients treated for PSD and 100 controls were matched for sex, age and body mass index (BMI). Pilocarpine iontophoresis was performed for 5 min, followed by 15 min of sweat collection. PSD patients sweated less than their matched pairs (18.4 ± 1.6 µl vs. 24.2 ± 2.1 µl, p = 0.03). Men sweated more than women (22.2 ± 1.2 µl vs. 15.0 ± 1.0 µl in non-PSD patients (p < 0.0001) and 20.0 ± 1.9 µl vs. 11.9 ± 2.0 µl in PSD patients (p = 0.051)). And regular exercisers sweated more than non-exercisers (29.1 ± 2.9 µl vs. 18.5 ± 1.6 µl, p = 0.0006 for men and 20.7 ± 2.3 µl vs. 11.4 ± 1.4 µl, p = 0.0005 for women). PSD patients sweat less than matched controls. Thus sweating may have a protective effect in PSD rather than being a risk factor.

This study aimed to identify concurrent thoracolumbar junction (TLJ) and sacrococcygeal (SC) fractures using a modified MRI protocol and analyze the risk factors associated with tandem fractures. We retrospectively investigated patients with MRI-confirmed TLJ fractures from January 2017 to March 2020. Patients were divided into two study groups: study 1 with a modified MRI protocol and study 2 with a routine protocol. The modified protocol included an extended field of view of sagittal scans in L-spine MRI covering the full SC spine. In study 1, frequency of concurrent TLJ and SC fractures was investigated. And we analyzed risk factors and compared CT and MRI for detecting SC fractures. In study 2, co-occurrence of both fractures was investigated. A total of 176 and 399 patients with TLJ fractures were enrolled in study 1 and 2, then SC fractures were identified in 53 (30.14%) and 36 patients (9.02%), respectively. An axial loading trauma mechanism was a significant risk factor (Odds ratio 7.0, p < 0.001), and MRI was more sensitive than CT in detecting SC fractures (p < 0.002). Thus, a modified MRI protocol was useful to detect the high occurrence of SC fractures in TLJ fractures, which concurrent fractures increased by an axial loading mechanism.

Purpose: To evaluate clinical features at diagnosis, prognostic factors, and outcomes of malignant sacrococcygeal germ cell tumors (SC-GCTs) in patients enrolled in the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) TCG 2004 protocol., Patients and Methods: A prospective analysis was conducted on all consecutive patients diagnosed with malignant SC-GCTs between January 2004 and May 2017. Patients with stage I underwent surgery and subsequent surveillance, the others received pediatric cisplatinum-etoposide-bleomycin (pPEB) regimen and eventual deferred surgery., Results: Of 45 patients, 35 were females. Age at diagnosis ranged from 1 day to 3.6 years (median 1.6 years); 26 were stage IV. Of 38 patients who underwent surgery, pathology revealed yolk sac tumor (YST) in 27 and teratoma + YST/embryonal carcinoma in 11, while seven patients were diagnosed based on imaging and elevated levels of alpha-fetoprotein (AFP). Of six patients approached with surgery, only one relapsed and was rescued with first-line chemotherapy. Overall, 38 out of 45 achieved complete remission, three a partial remission, and four were resistant. Ten out of 41 patients who entered remission later relapsed and nine were rescued with a second-line treatment. We observed a global failure percentage of 31% and a 5-year overall survival (OS) and event-free survival (EFS) of 95% and 69%, respectively., Conclusions: Chemotherapyis generally effective in malignant SC-GCTs, even though almost one-third of our patients experienced events salvageable with second-line treatment. Most of the relapses occurred within 1 year from diagnosis. A close follow up with serial AFP level monitoring should be done for at least 2 years after diagnosis., (© 2020 Wiley Periodicals LLC.)

Background: Chordoma is a rare malignant tumor of the axial skeleton. Percutaneous cryoablation (PCA) is a minimally invasive technique that allows freezing of tumors under imaging control. The purpose of our retrospective study was to investigate the outcome of PCA in a selected cohort of patients with sacrococcygeal chordoma, with a minimum of 5 years follow-up., Materials and Methods: Four patients were treated in 10 sessions. The mean follow-up was 57.3 months. We evaluated the feasibility, the procedure-related complications, the impact on pain control and oncological outcomes., Results: Freezing of 100% of the tumor volume was possible in 60%. Pain control was not reliably evaluable. Local recurrence occurred in 90% of the treated lesions; the mean time to progression was 8.1 months (range 1.5-16). At last follow-up, one patient had died of the disease, one of another cause and one was receiving the best supportive care. The only patient alive without the disease had received additional carbon-ion radiotherapy. The 5-year survival rate after index PCA was 50%., Conclusion: Complete freezing of the tumor was technically challenging, mainly due to the complex local anatomy. Recurrence occurred in 90% of the lesions treated. PCA should be considered with caution in the curative management of sacrococcygeal chordoma., (© 2020 Wiley Periodicals LLC.)

Abstract: Although the incidence of malignant sacrococcygeal germ cell tumors (MSGCTs) is high in the East Asian countries, information about MSGCTs from this region is limited. This report aimed to analyze the data of children with MSGCTs in a single medical center in Taiwan.Patients aged 18 years or younger with primary MSGCTs or malignant recurrence of a sacrococcygeal teratoma who underwent surgery during the neonatal period between January 1999 and December 2016 were identified from the Linkou Chang Gung Cancer Center registry. The clinical features, laboratory data, and treatment outcomes were reviewed.Fifteen children (1 man and 15 women) with MSGCTs were identified. Sacrococcygeal tumors were present at birth in 7 patients. All patients presented with a bulging mass at the buttock region and they had normal alpha-fetoprotein levels at the time of diagnosis. They underwent primary excision of the tumor. Immature teratoma was histologically diagnosed in 5 neonates, and mature teratoma in 2. Only 1 patient with grade 3 immature teratoma received adjuvant chemotherapy. Two patients with mature teratoma developed malignant recurrence 1.6 and 2.1 years later, respectively. Eight patients were diagnosed with MSGCTs after the neonatal period. The common presenting symptoms included buttock asymmetry (37.5%), abdominal distension (25%), and constipation (12.5%). Seven patients had elevated alpha-fetoprotein levels for their age. They were administered neoadjuvant chemotherapy followed by tumor excision if a residual tumor was present. The histology of the excised tumor included mature teratoma (66.7%) and necrosis (33.3%). One patient with a normal alpha-fetoprotein level underwent primary tumor excision followed by adjuvant chemotherapy. Grade 2 immature teratoma with embryonal carcinoma was diagnosed histologically. Among the 15 patients with MSGCTs, 3 had a recurrence (at age of 2.1, 0.5, and 2.4 years, respectively) and 1 died (at age of 6.1 years) of disease progression. The 5-year overall and event-free survival rates were 90% and 80%, respectively.Children with MSGCTs had good overall prognoses in this case series. For those with sacrococcygeal mature teratoma or low-grade immature teratoma in the neonatal period, we recommend close follow-up for at least 3 years after surgery to detect malignant recurrence., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The addition of topical fluid instillation, a programmable "dwell" time and a novel foam-wound interface to the established wound healing benefits of negative-pressure wound therapy (NPWT) works synergistically to benefit patients with complex wounds. This engineering breakthrough for wound care has been termed NPWT with instillation and dwell (NPWTi-d), and the new foam dressings are reticulated open cell foam dressings specifically designed for use with NPWTi-d. This combined technology has shown promise in chronic, complex wounds and has potential for the management of sacral and ischial pressure wounds., Methods: A qualitative comprehensive review was performed analyzing articles from PubMed and Medline that reported on the use of NPWTi-d in sacral or ischial pressure ulcers. Case series and case reports were predominant, and results of cases specific to sacral and ischial pressure wounds were extracted from larger studies and summarized for presentation., Results: Compared with conventional NPWT alone, NPWTi-d has been shown to help irrigate the wound, remove fibrinous debris, and promote granulation tissue formation. This is associated with a decreased number of operative debridements and decreased hospital length of stay., Conclusions: This technology is rapidly demonstrating expanded utilization in hospitalized patients with chronic sacral and ischial pressure ulcers. When used correctly, NPWTi-d serves as an effective "bridge to defined endpoint": whether that is a flap reconstruction, skin grafting, or discharge home with a stable chronic wound and simplified wound care., (Copyright © 2020 by the American Society of Plastic Surgeons.)

Purpose: To identify characteristics of critically ill adults with sacrococcygeal, unavoidable hospital-acquired pressure injuries (uHAPIs)., Design: Retrospective, matched, case-control design., Subjects/setting: Patients admitted to adult intensive care units (ICUs) at an urban academic medical center from January 2014 through July 2016., Methods: Thirty-four patients without uHAPI were matched to 34 patients with sacrococcygeal uHAPI. Time points of interest included admission to the ICU, the week preceding the definitive assessment date, and hospital discharge status. Variables of interest included length of stay, any diagnosis of sepsis, severity of illness, degree of organ dysfunction/failure, supportive therapies in use (eg, mechanical ventilation), and pressure injury risk (Braden Scale score)., Results: All 34 sacrococcygeal pressure injuries were classified as uHAPI using the pressure injury prevention inventory instrument. No statistically significant differences were noted between patients for severity of illness, degree of organ dysfunction/failure, or pressure injury risk at ICU admission. At 1 day prior to the definitive assessment date and at discharge, patients with uHAPI had significantly higher mean Sequential Organ Failure Assessment (SOFA) scores (greater organ dysfunction/failure) and lower mean Braden Scale scores (greater pressure injury risk) than patients without uHAPI. Patients with uHAPI had significantly longer lengths of stay, more supportive therapies in use, were more often diagnosed with sepsis, and were more likely to die during hospitalization., Conclusion: Sacrococcygeal uHAPI development was associated with progressive multiorgan dysfunction/failure, greater use of supportive therapies, sepsis diagnosis, and mortality. Additional research investigating the role of multiorgan dysfunction/failure and sepsis on uHAPI development is warranted., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 by the Wound, Ostomy and Continence Nurses Society.)

Background: Sacrococcygeal teratoma is one of the most common congenital tumors in newborns and infancy. The incidence is 1 per 20,000-40,000 live births. Ultrasonography is an optimal method for prenatal screening and diagnosis of fetal sacrococcygeal teratoma. MRI can be used to assist in the diagnosis. However, sacrococcygeal teratoma in the twin pregnancy is rare., Case Presentation: We reported a case of one twin with sacrococcygeal teratoma in dichorionic-diamniotic twin pregnancy.One twin with sacrococcygeal teratoma was diagnosed at the second trimester by ultrasonic examination and another twin was normal. A regular and careful antenatal care was conducted by the multidisciplinary team. The parents refused to perform the fetal MRI and examine the chromosome of both twin.At 37 + 1 of gestation, planned cesarean section was performed. The healthy male co-twin (twin A) weighed 2880 g.The male twin with SCT (twin B) weighed 2900 g, complying with 6 × 3 × 3 cm cystic and solid mass in sacrococcygeal region. At four days of age twin B underwent excisional surgery of the sacrococcygeal teratoma and coccyx and discharged 7 days after surgery. The mother and both babies were followed up and are all in good health until now., Conclusion(s): Sacrococcygeal teratoma in twin pregnancy is rare. Early antenatal diagnosis is important. Once the sacrococcygeal teratoma is diagnosed, clinicians should be aware of the associated maternal and fetal complications. Expecting parents should be counseled by the multidisciplinary team about the management and prognosis of the STC twin and co-twin. Prompt surgical excision of the sacrococcygeal teratoma after birth should be suggested.

Case Summary: An 84-year-old male patient was complaining of constipation and rectal bleeding for 6 months. Colonoscopy and rigid sigmoidoscopy showed a posterior upper rectal mass (13 cm from anus). Histopathology confirmed moderately differentiated adenocarcinoma. A CT scan of the thorax, abdomen, and pelvis, as well as pelvic magnetic nuclear resonance imaging, revealed midrectal cancer cT3N0M0 with clear predicted circumferential margin. The patient underwent anterior resection with tumor-specific total mesorectal excision and end colostomy. During the posterior rectal dissection, dilated fragile varicose presacral veins were damaged, and severe bleeding was observed. Initial pelvic packing was ineffective, as well as bone wax and clips. Internal iliac arteries were ligated, and additional packing was finally successful and the bleeding stopped. The patient was resuscitated with a total blood loss of 4.2 L. The bleeding did not recur, and the packs were removed on postoperative day 2. The postoperative course was uneventful, and the patient was discharged on postoperative day 13 from the initial operation and postoperative day 5 from packing removal.

In adults, both immature and mature ovarian teratomas show frequent genetic homozygosity consistent with tumorigenesis involving germ cells after meiosis I. Investigation into genetic zygosity of various teratomas in children has been limited. Thirteen sacrococcygeal, 12 ovarian, and 3 testicular teratomas in children 18 years or younger were retrieved from our departmental archives and histologically reviewed. Tumor and paired normal tissues were microdissected and subjected to short tandem repeat (STR) genotyping. DNA genotyping was informative in 12 sacrococcygeal teratomas, 8 ovarian teratomas, and 3 testicular teratomas. Sacrococcygeal teratomas included seven mature teratomas, four immature teratomas, and one mixed germ cell tumor with patient age ranging from 0 days to 3 years. All but two patients were female. Ovarian teratomas included five mature and three immature teratomas with patient age ranging from 2 to 18 years. Testicular teratomas included two mature teratomas and one immature teratoma with patient age ranging from 3 months to 3 years. All sacrococcygeal, testicular, and ovarian teratomas in patients younger than 4 years showed no evidence of genetic homozygosity by STR genotyping. In contrast, all four ovarian teratomas in patients older than 9 years showed either partial or complete homozygosity. In conclusion, unlike adolescent and adult ovarian teratomas, prepubertal sacrococcygeal and gonadal teratomas lack genetic homozygosity, supporting the hypothesis that teratomas before puberty develop at an early stage of germ cell development different from that of teratomas in adolescents and adults.

Background: Sacrococcygeal teratoma (SCT) is the most common teratoma in neonates and arises from the coccyx. SCT with intraspinal invasion is extremely rare and only reported in a few cases., Methods: 37 patients with SCT were identified at our institution between 2000 and 2018. Three of these patients had SCT with intraspinal extension. A literature review for intraspinal extension associated with SCT, including mode of diagnosis, presentation, surgical approach and neurological sequelae, between 1993 and 2018 was also conducted., Results: The authors report three cases of infants who were antenatally and/or postnatally diagnosed with a sacrococcygeal teratoma extending into the spinal canal. We illustrate the challenges of accurate diagnosis and therapeutic management. Postnatal magnet resonance imaging (MRI) was the best method to define spinal anatomy and extension of the tumors prior to surgery. Management with a multidisciplinary team approach including neuroradiology, neurosurgery and general surgery was used in our two most recent patients. The literature review yielded 6 cases of SCT with intraspinal extension., Conclusion: Intraspinal extension in SCT is rare but should be excluded at birth before attempting any resection. In case of positive spinal invasion on Ultrasonography (US), MRI is essential to plan for surgery and possible laminectomy to be able to perform a radical resection of this congenital tumor. We recommend this multidisciplinary approach., Level of Evidence: Level IV., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: This study aimed to analyze the oncological long-term results and late toxicity of carbon ion-based radiotherapy (RT) of patients with sacral chordoma and to identify potential prognostic factors for local control (LC) and overall survival (OS)., Methods: A total of 68 patients with sacral chordoma treated at the Heidelberg Ion Beam Therapy Center were included in this study. Of these 52 patients (77%) received a primary RT and 16 patients (23%) received a RT in a recurrent situation. All patients were treated with carbon ion RT (CIRT), either in combination with photons (n = 22; 32%) or as a monotherapy (n = 46; 68%), with a median radiation dose of 66 Gy RBE (range 60-74 Gy). In 40 patients (59%), RT was performed in the postoperative situation. Postoperative care included regular MRI scans. Local progression was defined as an enlargement of the maximum tumor diameter by 10% or a new tumor growth within the planning target volume (PTV). LC and OS were determined using the Kaplan-Meier method. Furthermore, the relevance of various prognostic factors for LC and OS was assessed by univariate and multivariate analysis., Results: The median follow-up period was 60 months (range 1.3-97.4 months). The 5-year rates for LC, progression-free survival, metastasis-free survival and OS were 53, 53, 52 and 74%, respectively. Local recurrence was observed in 31 patients (46%), occurring after a median follow-up time of 25 months (range 2.5-73.1 months). Only 10% of local recurrences occurred later than 5 years after RT. Statistical analysis showed that RT in the relapse situation corresponded to inferior LC rates compared to the primary situation, while other factors such as the GTV, radiation dose (EQD2) and treatment approach (CIRT alone vs. CIRT combined with photons) were insignificant. For OS after RT, patient age and PTV size proved to be significant predictors. The incidence of late toxicity ≥ III° according to CTCAE v5.0 was 21%. Sacral insufficiency fractures occurred in 49% of patients (maximum III°: 16%) and were thus by far the most frequent late side effect in our analysis. Radiogenic damage to the peripheral nerves, intestinal tract and skin was observed in only 9% (≥ III°: 5%), 3% (all II°) and 9% (all I°) of patients., Conclusion: Our analysis showed only moderate long-term LC rates after carbon ion-based RT, with sacral chordomas having a particularly poor prognosis in the recurrent situation. Therefore, future studies should evaluate the safety and effectiveness of further dose escalation and hypofractionation of RT in sacral chordoma and weight potential benefits of dose escalation against side effects.

The coccygeal region has complex anatomy, much of which may contribute to or be the cause of coccyx region pain (coccydynia). This anatomy is well depicted at imaging, and management is often dictated by what structures are involved. Coccydynia is a common condition that is known to be difficult to evaluate and treat. However, imaging can aid in determining potential causes of pain to help guide management. Commonly, coccydynia (coccygodynia) occurs after trauma and appears with normal imaging features at static neutral radiography, but dynamic imaging with standing and seated lateral radiography may reveal pathologic coccygeal motion that is predictive of pain. In addition, several findings seen at cross-sectional imaging in patients with coccydynia can point to a source of pain that may be subtle and easily overlooked. Radiology can also offer a role in management of coccygeal region pain with image-guided pain management procedures such as ganglion impar block. In addition to mechanical coccyx pain, a host of other conditions involving the sacrococcygeal region may cause coccydynia, which are well depicted at imaging. These include neoplasm, infection, crystal deposition, and cystic formations such as pilonidal cyst. The authors review a variety of coccydynia causes, their respective imaging features, and common management strategies. © RSNA, 2020.