Zusammenfassung Hintergrund Atypische chondrogene Tumoren (ACT) der kurzen und langen Röhrenknochen, früher als Chondrosarkome G1 bezeichnet, verhalten sich lokal aggressiv, haben aber ein sehr geringes Metastasierungspotenzial. Die Abgrenzung zu benignen Enchondromen ist aus klinischer, radiologischer und histopathologischer Sicht komplex. Ziel der Arbeit Epidemiologie, Diagnostik und Therapie von ACT unter besonderer Berücksichtigung der Abgrenzung zu Enchondromen werden dargestellt. Material und Methoden Es erfolgt die Zusammenfassung der internationalen Fachliteratur zu ACT und Enchondromen. Ergebnisse Die Inzidenz von Enchondromen, und mehr noch von ACT, ist über die Jahre angestiegen, was auf häufiger werdende Diagnostik hinweist. Im Gegensatz zu Enchondromen können ACT mit Schmerzen verbunden sein und radiologische Zeichen aggressiven Wachstums, wie tiefes endosteales Scalloping, aufweisen. Die alleinige Biopsie zur Differenzierung zwischen Enchondromen und ACT ist oft nicht hilfreich, da aufgrund der punktuellen Probegewebsentnahme ein „sampling error“ resultieren kann. Die definitive operative Therapie von ACT der langen und kurzen Röhrenknochen hat sich über die letzten Jahre gewandelt, weg von einer radikalen Tumorentfernung hin zu intraläsionaler Kürettage. Ein Zuwarten ist bei radiologischem Verdacht auf das Vorliegen eines Enchondroms regelmäßigen Verlaufskontrollen mittels Magnetresonanztomographie (MRT) möglich. Schlussfolgerungen ACT weisen im Gegensatz zu Enchondromen radiologische Zeichen eines aggressiven Wachstums auf. Die heutzutage bevorzugte Therapie besteht aus einer intraläsionalen Kürettage. Sowohl Diagnostik als auch Therapie und Nachsorge von kartilaginären Tumoren sollten an einem spezialisierten Tumorzentrum erfolgen.

Summary Background Osteoid osteomas of the foot are rare, with a varying and atypical clinical as well as radiological presentation impeding early diagnosis and treatment. The aim of the present multicentre study was to 1) analyze epidemiological, clinical and radiological findings of patients with foot osteoid osteomas and to 2) deduce a diagnostic algorithm based on the findings. Methods A total of 37 patients (25 males, 67.6%, mean age 23.9 years, range 8–57 years) with osteoid osteomas of the foot were retrospectively included, treated between 2000 and 2014 at 6 participating tertiary tumor centres. Radiographic images were analyzed, as were patients’ minor and major complaints, pain relief and recurrence. Results Most osteoid osteomas were located in the midfoot ( n = 16) and hindfoot ( n = 14). Painful lesions were present in all but one patient (97.3%). Symptom duration was similar for hindfoot and midfoot/forefoot ( p = 0.331). Cortical lesions required fewer x‑rays for diagnosis than lesions at other sites ( p = 0.026). A typical nidus could be detected in only 23/37 of x‑rays (62.2%), compared to 25/29 CT scans (86.2%) and 11/22 MRIs (50%). Aspirin test was positive in 18/20 patients (90%), 31 patients (83.8%) underwent open surgery. Pain relief was achieved in 34/36 patients (outcome unknown in one), whilst pain persisted in two patients with later confirmed recurrence. Conclusions As previously reported, CT scans seem to be superior to MRIs towards detection of the typical nidus in foot osteoid osteomas. In patients with unclear pain of the foot and inconclusive x‑rays, osteoid osteoma should be considered as differential diagnosis.

Background: Despite tremendous advantages in the development and application of megaprostheses in tumour and revision surgery, complications are still not infrequently observed. Only two studies investigating the outcome of the LPS (TM) system in the proximal femur and distal femur/proximal tibia have been published thus far. Herein, mid-term implant survival rates one of the largest cohort of patients treated with the LPS (TM)-system are presented aiming tp answer: 1) How is the outcome of the LPS (TM) system in the proximal femur and distal femur/proximal tibia? 2) Which factors are associated with altered implant survival? 3) What is the cumulative risk of complications according to Henderson? Hypothesis: The LPS (TM)-system is associated with high complication rates that depend on implant site, with infections being most common. Patients and methods: Fifty-seven patients who received the LPS (TM)-system at the proximal femur (n = 31), distal femur (n = 21) and proximal tibia (n = 5) between 2004 and 2010 for oncological (n = 40) or nononcological (n =17) causes, were retrospectively included. Median follow-up was 5.0 years (range, 0-12.4 years). Complications were classified according to Henderson into instability/soft tissue failure (type 1), aseptic loosening (type 2), structural failure (type 3), periprosthetic infection (type 4), tumour progression (type 5). Competing-risk-analyses were applied to estimate implant survival with death as the competing event. Results: Twenty-six patients (45.6%) developed a complication, of whom 9 (29.0%) had a proximal femoral and 17 (65.4%) a distal femoral/proximal tibial implant. Type 4 complications were most common (n =11), followed by type 3 (n = 6, including 2 yoke-fractures), type 1 and 2 (n = 4 each), and type 5 (n =1). The only factor associated with the development of complications in the multivariate model was a distal femoral/proximal tibial implant (hazard-ratio: 7.418, 95% confidence-interval: 2.193-26.096, p = 0.001), irrespective of reason for reconstruction and use of muscular flaps. The cumulative-incidence of failure including all complications was 34.3%, 40.7% and 67.1% at 3, 5 and 10 years, respectively. Discussion: The LPS (TM)-system may be used for proximal femoral reconstructions both in the oncological and non-oncological setting. Rates of complications are higher in our cohort than reported in literature for other, comparable, megaprosthesis systems. Especially in the distal femur/proximal tibia, complication rates were high, partially attributable to the former implant design leading to fractures of the yoke-mechanism. As the implant has been remodelled after these issues became evident, there is no objection to use this megaprosthesis system today. (C) 2019 Elsevier Masson SAS. All rights reserved.

Myxofibrosarcoma (MFS) is one of the most common sarcoma subtype in elderly patients. They are reported to recur locally independently of the tumour grade in 30–40% of cases and metastases are reported to develop in high-grade tumours in 20–35% cases. As MFS is a rare diagnosis, data investigating specific survival and independent risk factors are lacking and have mostly been limited to single orthopaedic oncology centre studies so far. Thus we set up a pathology-based retrospective study and analyzed all MFS diagnosed in our institution with the following aims: (1) analysis of independent risk factors for overall survival, disease specific survival, local recurrence-free survival and distant metastasis free survival following resection of MFS and (2) analysis of resection margin status. High-grade MFS have a low survival distant metastasis free survival and local recurrence-free survival is dependent on surgical margin status. We retrospectively analysed 109 patients (median 66 years [range, 21–96]) diagnosed with MFS and a median follow-up of 42 months at one centre between 1990 and 2014. Tumor-associated survival, including competing risk analysis, and prognostic factors for local recurrence, metastatic disease and death from disease were investigated and included in a multivariate analysis. Overall survival was 79% [95% CI: 71.9–87.5] at 3 years and 76% [95% CI: 67.4–84.6] at 5 years. Disease specific survival was 85% [95% CI: 78.4–92.2] at 3 years and 80% [95% CI: 72.2–88.2] at 5 years. There were local recurrences in 11/109 patients (10%). Local recurrence-free survival (LRFS) was 95% [95% CI: 92.0–99.8] at 3 and 88% [95% CI: 84.3–96.4] at 5 years. Metastatic disease (n = 25; 23%) occurred after a median follow-up of 10 months. Distant metastasis free survival was 78% [95% CI: 69.9–85.9] at 3 and 77% [95% CI: 68.4–84.8] at 5 years. R1 status at primary resection was an independent risk factor for decreased local recurrence-free survival (OR: 8.5, 95% CI: 1.59–49.79 [p = 0.01]). Grading was an independent risk factor for decreased disease specific survival (OR 13.4, 95% CI: 1.65–1734.84 [p = 0.01]) and distant metastasis free survival (OR 16.2, 95% CI: 2.0–2110.5 [p = 0.004]). Primary resection achieved R0 margins in 63 (58%) of 109 patients. Margins were adequate significantly more often (p < 0.001) in patients treated primarily at a sarcoma centre (R0 = 58/68, 85%) than in those treated primarily at non-sarcoma centres (R0 = 5/41, 12%), whereby the latter significantly more often treated superficial tumours (p = 0.001) with a size of less than 5 cm (p < 0.001). Patients with high-grade MFS had a poorer prognosis with respect to Disease specific survival/Distant metastasis free survival than low-grade MFS. Local recurrence did not significantly affect disease specific survival. IV.

BACKGROUND AND OBJECTIVES:Expandable distal femur prostheses have become more popular over the last decades, but scientific data is limited.METHODS:A retrospective study was performed, including cases treated between 1986 and 2019 in 15 European referral centers for bone sarcomas.RESULTS:A total of 299 cases were included. Average follow-up was 80 months (range, 8-287 months). Mean patient age was 10 years. Most (80%) of the implants were noninvasive growers and a fixed hinge knee was used more often (64%) than a rotating hinge. Most prosthetic designs showed good (>80%) implant survival at 10 years, but repeat surgery was required for 63% of the patients. The most frequent reason for revision procedure was the completion of lengthening potential. Noninvasive expandable implants showed less risk of infection compared to invasive growers (11.8% vs 22.9% at 10 years). No difference in aseptic loosening was found between cemented and uncemented stems.CONCLUSIONS:This study shows the increasing popularity of expandable distal femur prostheses, with overall good results for function and implant survival. However, repeat surgery is frequently required, especially in patients under the age of 10 years old. Infection is less frequent in noninvasive growers compared to implants that require invasive lengthening procedures.

Despite tremendous advantages in the development and application of megaprostheses in tumour and revision surgery, complications are still not infrequently observed. Only two studies investigating the outcome of the LPS™ system in the proximal femur and distal femur/proximal tibia have been published thus far. Herein, mid-term implant survival rates one of the largest cohort of patients treated with the LPS™-system are presented aiming tp answer: (1) How is the outcome of the LPS™ system in the proximal femur and distal femur/proximal tibia? (2) Which factors are associated with altered implant survival? (3) What is the cumulative risk of complications according to Henderson? The LPS™-system is associated with high complication rates that depend on implant site, with infections being most common. Fifty-seven patients who received the LPS™-system at the proximal femur (n = 31), distal femur (n = 21) and proximal tibia (n = 5) between 2004 and 2010 for oncological (n = 40) or non-oncological (n = 17) causes, were retrospectively included. Median follow-up was 5.0 years (range, 0–12.4 years). Complications were classified according to Henderson into instability/soft tissue failure (type 1), aseptic loosening (type 2), structural failure (type 3), periprosthetic infection (type 4), tumour progression (type 5). Competing-risk-analyses were applied to estimate implant survival with death as the competing event. Twenty-six patients (45.6%) developed a complication, of whom 9 (29.0%) had a proximal femoral and 17 (65.4%) a distal femoral/proximal tibial implant. Type 4 complications were most common (n = 11), followed by type 3 (n = 6, including 2 yoke-fractures), type 1 and 2 (n = 4 each), and type 5 (n = 1). The only factor associated with the development of complications in the multivariate model was a distal femoral/proximal tibial implant (hazard-ratio: 7.418, 95% confidence-interval: 2.193–26.096, p = 0.001), irrespective of reason for reconstruction and use of muscular flaps. The cumulative-incidence of failure including all complications was 34.3%, 40.7% and 67.1% at 3, 5 and 10 years, respectively. The LPS™-system may be used for proximal femoral reconstructions both in the oncological and non-oncological setting. Rates of complications are higher in our cohort than reported in literature for other, comparable, megaprosthesis systems. Especially in the distal femur/proximal tibia, complication rates were high, partially attributable to the former implant design leading to fractures of the yoke-mechanism. As the implant has been remodelled after these issues became evident, there is no objection to use this megaprosthesis system today. IV, observational study.

Background: Myxofibrosarcoma (MFS) is one of the most common sarcoma subtype in elderly patients. They are reported to recur locally independently of the tumour grade in 30-40% of cases and metastases are reported to develop in high-grade tumours in 20-35% cases. As MFS is a rare diagnosis, data investigating specific survival and independent risk factors are lacking and have mostly been limited to single orthopaedic oncology centre studies so far. Thus we set up a pathology-based retrospective study and analyzed all MFS diagnosed in our institution with the following aims: (1) analysis of independent risk factors for overall survival, disease specific survival, local recurrence-free survival and distant metastasis free survival following resection of MFS; (2) analysis of resection margin status. Hypothesis: High-grade MFS have a low survival distant metastasis free survival and local recurrence free survival is dependent on surgical margin status. Patients and Methods: We retrospectively analysed 109 patients (median 66 years [range, 21-96]) diagnosed with MFS and a median follow-up of 42 months at one centre between 1990 and 2014. Tumor-associated survival, including competing risk analysis, and prognostic factors for local recurrence, metastatic disease and death from disease were investigated and included in a multivariate analysis. Results: Overall survival was 79% [95%CI: 71.9-87.5] at 3 years and 76% [95%CI: 67.4-84.6] at 5 years. Disease specific survival was 85% [95%CI: 78.4-92.2] at 3 years and 80% [95%CI: 72.2-88.2] at 5 years. There were local recurrences in 11/109 patients (10%). Local recurrence free survival (LRFS) was 95% [95%CI: 92.0-99.8] at 3 and 88% [95%CI: 84.3-96.4] at 5 years. Metastatic disease (n= 25; 23%) occurred after a median follow-up of 10 months. Distant metastasis free survival was 78% [95%CI: 69.9-85.9] at 3 and 77% [95%CI: 68.4-84.8] at 5 years. R1 status at primary resection was an independent risk factor for decreased Local Recurrence-free survival (OR: 8.5, 95%CI: 1.59-49.79 [p = 0.01]). Grading was an independent risk factor for decreased Disease specific survival (OR 13.4, 95%CI: 1.65-1734.84 [p = 0.01 ]) and Distant metastasis free survival (OR 16.2, 95%CI: 2.0-2110.5 [p = 0.004]). Primary resection achieved R0 margins in 63 (58%) of 109 patients. Margins were adequate significantly more often (p < 0.001) in patients treated primarily at a sarcoma centre (R0 = 58/68, 85%) than in those treated primarily at nonsarcoma centres (R0= 5/41,12%), whereby the latter significantly more often treated superficial tumours (p = 0.001) with a size of less than 5 cm (p < 0.001). Discussion: Patients with high-grade MFS had a poorer prognosis with respect to Disease specific survival/Distant metastasis free survival than low-grade MFS. Local recurrence did not significantly affect disease specific survival. (C) 2020 Elsevier Masson SAS. All rights reserved.

We analysed socio-economic- and health-related quality of life (primary outcome) and radiological outcome (secondary outcome) 5 years after full time rigid bracing (FTRB) plus physiotherapeutic scoliosis-specific exercises (PSSE) in adolescent idiopathic scoliosis.

BACKGROUND:Endoprosthetic reconstruction of massive bone defects has become the reconstruction method of choice after limb-sparing resection of primary malignant tumors of the long bones. Given the improved survival rates of patients with extremity bone sarcomas, an increasing number of patients survive but have prosthetic complications over time. Several studies have reported on the outcome of first endoprosthetic complications. However, no comprehensive data, to our knowledge, are available on the likelihood of an additional complication and the associated risk factors, despite the impact of this issue on the affected patients.QUESTIONS/PURPOSES:(1) What are the types and timing of complications and the implant survivorship free from revision after the first complication? (2) Does survivorship free from repeat revision for a second complication differ by anatomic sites? (3) Is the type of first complication associated with the risk or the type of a second complication? (4) Are patient-, tumor-, and treatment-related factors associated with a higher likelihood of repeat revision?METHODS:Between 1993 and 2015, 817 patients underwent megaprosthetic reconstruction after resection of a tumor in the long bones with a single design of a megaprosthetic system. No other prosthetic system was used during the study period. Of those, 75% (616 of 817) had a bone sarcoma. Seventeen patients (3%) had a follow-up of less than 6 months, 4.5% (27 of 599) died with the implant intact before 6 months and 43% (260 of 599 patients) underwent revision. Forty-three percent of patients (260 of 599) experienced a first prosthetic complication during the follow-up period. Ten percent of patients (26 of 260) underwent amputation after the first complication and were excluded from further analysis. Second complications were classified using the classification of Henderson et al. to categorize surgical results. Briefly, this system categorizes complications as wound dehiscence (Type 1); aseptic loosening (Type 2); implant fractures or breakage and periprosthetic fracture (Type 3); infection (Type 4); and tumor progression (Type 5). Implant survival curves were calculated with the Kaplan-Meier method and compared using the log-rank test. Hazard ratios (HR) were estimated with their respective 95% CIs in multivariate Cox regression models.RESULTS:A second complication occurred in 49% of patients (115 of 234) after a median of 17 months (interquartile range [IQR] 5 to 48) after the surgery for the first complication. The time to complication did not differ between the first (median 16 months; IQR 5 to 57) and second complication (median 17 months; IQR 5 to 48; p = 0.976). The implant survivorship free from revision surgery for a second complication was 69% (95% CI 63 to 76) at 2 years and 46% (95% CI 38 to 53) at 5 years. The most common mode of second complication was infection 39% (45 of 115), followed by structural complications with 35% (40 of 115). Total bone and total knee reconstructions had a reduced survivorship free from revision surgery for a second complication at 5 years (HR 2.072 [95% CI 1.066 to 3.856]; p = 0.031) compared with single joint replacements. With the numbers we had, we could not show a difference between the survivorship free of revision for a second complication based on the type of the first complication (HR 0.74 [95% CI 0.215 to 2.546]; p = 0.535). We did not detect an association between total reconstruction length, patient BMI, and patient age and survivorship free from revision for a second complication. Patients had a higher risk of second complications after postoperative radiotherapy (HR 1.849 [95% CI 1.092 to 3.132]; p = 0.022) but not after preoperative radiotherapy (HR 1.174 [95% CI 0.505 to 2.728]; p = 0.709). Patients with diabetes at the time of initial surgery had a reduced survivorship free from revision for a second complication (HR 4.868 [95% CI 1.497 to 15.823]; p = 0.009).CONCLUSIONS:Patients who undergo revision to treat a first megaprosthetic complication must be counseled regarding the high risk of future complications. With second complications occurring relatively soon after the first revision, regular orthopaedic follow-up visits are advised. Preoperative rather than postoperative radiotherapy should be performed when possible. Future studies should evaluate the effectiveness of different approaches in treating complications considering implant survivorship free of revision for a second complication.LEVEL OF EVIDENCE:Level III, therapeutic study.

BACKGROUND:We aim to investigate the prognostic implications of synchronous skip metastases in osteosarcoma by presenting the largest single centre series to date. METHODS:Retrospective study of 21 osteosarcoma patients with skip metastases treated between 1983 and 2004. RESULTS:No statistical difference in overall survival was demonstrated when comparing presence of lung metastases to those without (p = 0.859). No statistical difference was found in overall survival according to age group (<18yrs vs >18yrs; p = 0.126), or to percentage chemotherapy-induced bone necrosis (<90% vs >90%; p = 0.056). CONCLUSIONS:The presence of skip metastases confers a very poor prognosis as an independent variable. LEVEL OF EVIDENCE:III.

Treatment of unicameral bone cysts (UBC) in the humerus with drainage screws is scarcely reported in the literature. The aim of this retrospective study was to compare drainage screws and alternative treatment methods with respect to the number of required surgical procedures to achieve sufficient UBC healing, postoperative fractures/recurrences/complications, and radiological outcome. Medical archives of two tertiary orthopedic referral centers were screened for all patients who were treated surgically for humeral UBC in the period 1991–2015 with a histologically/cytologically confirmed diagnosis. Sex, age, all surgical procedures, fractures, complications, recurrences, and the final radiological outcome were compared between patients treated with drainage screws, elastic intramedullary nails, or curettage with optional grafting. The study included 106 operated patients with a mean age of 10.3 years, with a mean follow-up of 5.7 years. The average number of UBC-related surgical procedures in sex-matched and age-matched treatment groups was 2.7 with drainage screws, 2.8 with intramedullary nails, and 3.5 with curettage/grafting ( P =0.54). Intramedullary nails (odds ratio 0.20) and older age (odds ratio for each year 0.83) predicted a lower risk of postoperative UBC recurrence. Patients with drainage screws had the highest UBC recurrence rates and the lowest rates of changed initial treatment method. There was no difference between the treatment groups in the postoperative fracture rate, complications, or the final radiological outcome. UBC treatment in the humerus therefore requires approximately three surgical procedures, irrespective of the treatment modality chosen. Adding an elastic intramedullary nail to a humeral UBC cyst may reduce recurrence risk and prevent further fractures. Level of Evidence: Level III – therapeutic retrospective comparative study.

Introduction. Indications discussed for the implantation of expandable prostheses in bone sarcoma patients are unclear. This survey aimed to analyse common practice with this implant type in orthopaedic oncology. Methods. A web-based survey was sent to 98 orthopaedic oncology surgeons. Factors reported in literature to influence the decision on the implantation of a growing prosthesis were covered in individual questions and three case scenarios. Results. The completion rate of the survey was 45% (n = 44). Twenty-seven of 44 surgeons (61%) had implanted between 1 and 15 expandable prostheses within three years. The minimum median patient age was 6.5 years, and 3–5 cm of predicted growth deficit was the minimum before implanting a growing prosthesis. One-third of surgeons do not use growth calculation methods. Two out of three surgeons would rather not implant a growing prosthesis in children with metastatic disease. Conclusions. Our survey confirmed the literature with 3-4 cm as the minimum estimated growth deficit. The minimum age for the implantation of a growing prosthesis is approx. 6.6 years, and therefore the patients are younger than those reported in previous publications. One-quarter of orthopaedic surgeons do not use growing prostheses at all. It remains unclear whether growing prostheses are indicated in patients with metastatic disease.

Aims The use of a noninvasive growing endoprosthesis in the management of primary bone tumours in children is well established. However, the efficacy of such a prosthesis in those requiring a revision procedure has yet to be established. The aim of this series was to present our results using extendable prostheses for the revision of previous endoprostheses. Patients and Methods All patients who had a noninvasive growing endoprosthesis inserted at the time of a revision procedure were identified from our database. A total of 21 patients (seven female patients, 14 male) with a mean age of 20.4 years (10 to 41) at the time of revision were included. The indications for revision were mechanical failure, trauma or infection with a residual leg-length discrepancy. The mean follow-up was 70 months (17 to 128). The mean shortening prior to revision was 44 mm (10 to 100). Lengthening was performed in all but one patient with a mean lengthening of 51 mm (5 to 140). Results The mean residual leg length discrepancy at final follow-up of 15 mm (1 to 35). Two patients developed a deep periprosthetic infection, of whom one required amputation to eradicate the infection; the other required two-stage revision. Implant survival according to Henderson criteria was 86% at two years and 72% at five years. When considering revision for any cause (including revision of the growing prosthesis to a non-growing prosthesis), revision-free implant survival was 75% at two years, but reduced to 55% at five years. Conclusion Our experience indicates that revision surgery using a noninvasive growing endoprosthesis is a successful option for improving leg length discrepancy and should be considered in patients with significant leg-length discrepancy requiring a revision procedure. Cite this article: Bone Joint J 2018;100-B:370–7.

Background and Aims: The GI tract is rarely affected by secondary tumors. Patients often present at an advanced stage of the disease, and prognosis is dismal. This study aimed to analyze the clinical, endoscopic, and pathologic features of secondary tumors that had been diagnosed endoscopically. Methods: We conducted a retrospective database analysis of 217 patients with secondary tumors of the GI tract. Endoscopic findings and histologic diagnoses were systematically re-evaluated. Results: Malignant melanoma (n=33, 15%), breast cancer (n=32, 15%), and pancreatic cancer (n=27, 12%) were the most common corresponding primaries. About one-third of secondary tumors were detected in the stomach (n=76, 35%), followed by small intestine (n=54, 25%) and rectum (n=53, 24%). The median time between the diagnoses of primary and secondary tumors was 19 months (mean, 31; range, 0-251), and this time was particularly long for renal cell carcinoma and breast cancer (median, 38 and 45 months, respectively). Direct invasion from extra-GI malignancies was more common (56%) than vascular cancer spread (44%) and depended on both sites of tumor involvement and corresponding primary. The lesions presented with various endoscopic patterns. In patients for whom a definitive diagnosis of cancer was known before the examination (n=168), a secondary tumor was included in the differential diagnosis in only 48% of lesions. It is of note that the remaining cases were diagnosed endoscopically as primary tumors and rarely also as nonneoplastic change. Conclusions: Secondary tumors may affect all parts of the GI tract. Malignant melanoma and breast and pancreatic cancer represent the most common primaries. Diagnosis based on examination of biopsy specimens is crucial to avoid misclassification.

Background: Intramuscular / cellular myxomas and low-grade myxofibrosarcomas are two different tumor entities with a significant histological overlap, especially if dealing with small biopsies. Despite the morphological similarities, they differ considerably in their biological behaviour. Intramuscular / cellular myxoma rarely shows signs of recurrence and never metastasizes, in contrast to myxofibrosarcoma that tends to recur more aggressively and to metastasize haematologically. Therefore, it is of great importance to distinguish these lesions - evaluation of GNAS mutation status could be of tremendous help. Methods: We reviewed 13 cases with intramuscular / cellular myxomas. The 13 cases included 5 men and 8 women, aged from 33 to 71 years (mean age 55.5 years). Immunohistochemistry was performed as well as next generation sequencing. Ten cases were located in the lower extremities and three cases were located in the upper extremities. Two lesions were initially misdiagnosed as a low-grade myxofibrosarcoma. Results: Performing next generation sequencing 12 out of 13 specimens showed a GNAS mutation. Conclusions: Our findings demonstrate that GNAS mutations are more common in intramuscular / cellular myxomas, than had been reported in literature in the past Next generation sequencing for determining GNAS mutation status on small biopsies or diagnostically challenging cases facilitates the diagnosis of intramuscular / cellular myxoma and separates this tumor entity from its mimics.

Myxofibrosarcomas are morphologically heterogeneous soft tissue sarcomas lacking a specific immunohistochemical expression profile and recurrent genetic changes. The study was designed to gain further insights into the molecular landscape of myxofibrosarcomas by targeted re-sequencing of known cancer driver hotspot mutations and the analysis of genomewide somatic copy number alterations. A well-defined group of myxofibrosarcomas, including myxofibrosarcomas G1 (n=6), myxofibrosarcomas G3 (n=7), myxofibrosarcomas with morphologically heterogeneous and independently selectable G1 and G3 areas within a tumor (n=8), and myxofibrosarcomas G3 with subsequent tumor recurrence (n=1) or metastatic disease (n=3) were evaluated. Mutational analysis demonstrated mutations in TP53, PTEN, FGFR3, CDKN2A, and RB1. TP53 mutations were seen in 11 (44%) of patients and detected in myxofibrosarcomas G1, G3, with heterogeneous morphology and G3 with subsequent metastases in 1 patient (16%), 3 patients (42%), 2 patients (62.5%), and 3 patients (75%), respectively. Additional mutations were detected in 2 patients, intratumoral mutational heterogeneity in 1 patient. We observed a variety of copy number alterations typical for myxofibrosarcomas, with higher numbers in G3 compared with G1 myxofibrosarcomas. Cluster analysis revealed distinctive features especially in metastatic and recurrent disease. Focal alterations affected CDKN2A, CCND1, CCNE1, EGFR, EPHA3, EPHB1, FGFR1, JUN, NF1, RB1, RET, TP53, and additional novel amplifications in CCNE1, KIT, EGFR, RET, BRAF, NTRK2 were seen in G3 compared with the G1 tumor areas. The total number of focal events in G1 versus G3 tumors differed significantly (P=0.0014). TRIO and RICTOR co-amplification was seen in 8 (44%) G3 and 1 (10%) G1 myxofibrosarcomas and RICTOR amplification alone in 4 (40%) G1 myxofibrosarcomas. TRIO amplification was significantly (P=0.0218) higher in G3 myxofibrosarcomas indicating a late genetic event. These findings support the use of expanded molecular profiling in myxofibrosarcomas to detect drug-able targets to allow patients to participate in basket trials.

Pädiatrische Patienten mit malignen Weichteil- oder Knochentumoren der Extremitäten stellen eine Herausforderung für die verantwortlichen Ärzte dar. Das chirurgische Management beinhaltet die Resektion des malignen Tumors mit einem ausreichenden Sicherheitsabstand zum gesunden Gewebe und der Rekonstruktion des Defekts. Dies ist sehr anspruchsvoll, da idealerweise die Extremität erhalten bleiben und gleichzeitig ein gutes funktionelles Ergebnis erzielt werden sollte. Chirurgische Techniken und Verfahren mit Megaprothesen oder biologischen Rekonstruktionen haben sich in den letzten 2 Jahrzehnten deutlich verbessert, dennoch sollte sich das Behandlungsverfahren weiter auf die Erwartungen des Patienten und der Familie fokussieren. Der vorliegende Beitrag fasst Diagnose und Behandlung von bösartigen Tumoren bei pädiatrischen Patienten sowie Vor- und Nachteile von verschiedenen chirurgischen Eingriffen zusammen.

Secondary tumours of the ampulla of Vater are rare. Underlying primary tumours, clinical presentation, macroscopic appearance, treatment strategies and outcome of secondary ampullary lesions have not been systematically analysed. The present case study reported a 57-year old patient with an ampullary metastasis from renal cancer and a literature review was performed in which a further 32 patients were included. The most common responsible primary tumours were malignant melanoma and renal clear cell carcinoma, followed by breast cancer. The time interval between the diagnosis of the primary tumour and the ampullary metastasis was highly variable, and may be as long as 10 years, particularly for renal cancer. Patients may present with unspecific abdominal discomfort, jaundice or upper gastrointestinal bleeding. The gross appearance was largely indistinguishable from that of a primary tumour. Lesions may present as polypoid or irregular, soft and friable tumour mass, in certain cases with superficial ulceration. In ~50% of cases, the ampullary metastasis was the only metastatic lesion, while in the remaining cases, the cancer had spread to one or more organs. The prognosis was generally poor. The management requires a multi-modal approach, including endoscopic, surgical and oncological procedure.

Purpose. Anterior screw fixation has become a popular surgical treatment method for instable odontoid fractures. Screw loosening and migration are a rare, severe complication following anterior odontoid fixation, which can lead to esophagus perforation and requires revision operation. Methods. We report a case of screw loosening and migration after anterior odontoid fixation, which perforated the esophagus and was excreted without complications in a 78-year-old male patient. Results. A ventral dislocated anterior screw perforated through the esophagus after eight years after implantation and was excreted through the gastrointestinal (GI) tract. At a 6-month follow-up after the event the patient was asymptomatic. Conclusion. Extrusion via the GI tract is not safe enough to be considered as a treatment option for loosened screws. Some improvements could be implemented to prevent such an incident. Furthermore, this case is a fine example that recent preoperative imaging is mandatory before revision surgery for screw loosening.