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Background An ectopic hepatocellular carcinoma (EHCC) arises from the ectopic liver which is defined as a hepatic organ or tissue not connected to surrounding tissues. EHCC is a rare disease and it is difficult to diagnose preoperatively. Furthermore, the clinical features are not fully elucidated. Case summary A retroperitoneal tumor (6 cm) was located at the dorsal side of the pancreas head on abdominal ultrasonography in an 81-year old woman positive for hepatitis C virus antibody. Contrast enhanced-computed tomography and gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging showed viable HCC patterns with early enhancement and delayed washout. The tumor markers - serum alpha-fetoprotein and alpha-fetoprotein-L3% - were increased to 30.1 ng/mL and 83.1%, respectively. Protein induced by vitamin K absence or antagonist-II was within normal levels (17 mAU/mL). Positron emission tomography-computed tomography showed strong accumulation into the tumor (Standardized Uptake Value max: 13.8), and the tumor cytology following endoscopic ultrasound-guided fine needle aspiration showed poorly differentiated carcinoma. Tumor extirpation was performed, and operative findings showed that the retroperitoneal tumor was disconnected from the pancreas and the liver. Swollen lymph nodes near the tumor were histologically normal. On histological examination, the tumor was finally diagnosed as EHCC with Arginase-1 positive expression. Conclusion We report our experience of a rare EHCC which was difficult to diagnose, and we present a review of the literature.

BACKGROUND. Resection of recurrent retroperitoneal well-differentiated liposarcoma (RP-WDLPS) is unlikely to result in cure. Thus, most clinicians delay surgery after recurrence until symptom intolerance or increasing rate of disease progression. The aim of this study was to determine whether longer surveillance intervals in this population would impact outcomes or delay treatment in those who recur. METHODS. A retrospective review of patients with primary RP-WDLPS who underwent resection between April 1996 and April 2017 and surveillance at MDACC (n = 91) was performed. RESULTS. Median age at diagnosis of primary RP-WDLPS was 61 years; median tumor size was 30 cm. Complete resection was achieved in 85 (93.4%) patients. Among patients who underwent complete resection, recurrence occurred in 53 (60.2%) with median time to recurrence of 27.0 months. Thirty-six (69.6%) of these patients underwent resection of recurrent disease at a median 40.2 months from primary tumor resection. Surveillance imaging at 4-month (vs 3-month) intervals would not have impacted recurrence management in 84 (95.5%) patients; imaging at 6-month (vs 3-month) intervals would not have impacted management of recurrence in 80 (90.9%). CONCLUSIONS. Recurrence was common, often occurring beyond the early postoperative period following primary RP-WDLPS resection. More frequent surveillance imaging (q3–4 vs q6 months) in the first 2 years following primary RP-WDLPS resection may not significantly impact timing of surgery or systemic therapy for recurrence. If longer surveillance intervals were shown to be safe with equivalent outcomes in prospective studies, the resulting change in practice could lead to decreased anxiety and cost for patients and healthcare systems.

Paragangliomas (PGLs) arise from chromaffin cells of the extra-adrenal sites along the sympathetic and/or the parasympathetic chain. Majority of the PGLs occur in the abdomen. When retroperitoneal PGLs produce symptoms of compression or invasion of adjacent organs, they could be misdiagnosed as a tumor of adjacent organs. Here, we report a rare case of ureteral obstruction caused by an extra-adrenal retroperitoneal PGL that mimicked a ureteral tumor. A 46-year-old female presented with a 2-year history of hypertension. Routine laboratory tests were unremarkable. The computed tomography (CT) scan showed a hypervascular mass located in the left mid-ureteral section. Ureteropyelography revealed left ureteral obstruction at the level of L4 to L5 vertebrae and hydroureteronephrosis. Cystoscopy confirmed left ureteral obstruction. Based on the clinical and imaging findings, a left ureteral tumor was suspected preoperatively. The tumor was completely resected, and the involved segment of the ureter was removed. No significant enlarged lymph nodes were seen in the pelvic cavity and retroperitoneum. A histopathological examination of the tumor confirmed retroperitoneal PGL partly infiltrating the ureter. The patient's blood pressure returned to the normal range postoperatively. Our case demonstrates the importance of considering extra-adrenal PGL in the differential diagnosis of retroperitoneal tumors.

The most frequent tumoral condition of the uterus is represented by uterine myoma. The diagnosis, in most cases, is established by clinical examination and ultrasound scan. Nevertheless, there are rare cases, in which the surgical findings reveal a retroperitoneal tumor instead of a uterine myoma. These could be represented by schwannomas or Castleman disease. The schwannomas are rarely malignant and arise from the Schwann cells of nerve fibers. These tumors are frequently found at the level of the head, neck and mediastinum and rarely in the pelvis. Generally, schwannomas localized at retroperitoneal level are asymptomatic and with a very slow growth rate. The treatment consists in complete surgical resection. The recurrence rate is low and, generally, the prognosis is good. The Castleman disease is considered a rare entity, but it should be always taken into consideration when it comes to a differential diagnosis in a young patient who presents a retroperitoneal mass at imagery exams. The condition affects the lymphatic system and is characterized by a hyperplasia of the lymph nodes, sometimes associated with herpes virus infection. The clinical picture is often non-specific; the pain may be the only symptom. The imaging methods are not always conclusive for the final positive diagnosis and the histopathological examination is always necessary. Pelvic Castleman disease can be misdiagnosed as myoma or an adnexal tumor. In this article, we review the present knowledge regarding the pathogenesis, pathology and management of these rare retroperitoneal tumors. Both conditions, when located in pelvis must be taken into consideration in the differential diagnosis of uterine myomas, especially in the pedunculated form.

The efficacy of an immune checkpoint blockade has been demonstrated against various types of cancer, but its suitability has not been fully proven for therapies specifically targeting sarcoma. We conducted a pan-cancer tumor data analysis to identify key immune-related variables strongly associated with sarcoma prognosis, and we explored whether these expected factors are functionally correlated with anti-PD-1 therapy in humanized (Hu) NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice xenografted with dedifferentiated liposarcoma (DDLPS). We found that an abundance of hCD8+ T cells and hNK cells was functionally associated with anti-PD-1 effects in the Hu-NSG DDLPS mice. Phenotypically, these cells were shown to be hCD8+IFNγ+, hCD8+PD-1+, hCD8+Ki-67+, hCD56+IFNγ+, hCD56+PD-1+, and hCD56+Ki-67+ cells and were enriched in splenocytes and tumor-infiltrating lymphocytes (TILs) of Hu-NSG DDLPS mice treated with anti-PD-1 antibody. Moreover, a considerable increase in activated hCD56+NKp46+NKG2D+ NK cells was also detected. Our findings suggest that hCD8+ T and hNK subsets play a pivotal role in anti-DDLPS tumor effects of anti-PD-1 therapy. The results provide clinical reference for advanced anti-PD-1 therapy targeting sarcoma tumors including DDLPS.

Introduction Iliocaval leiomyosarcoma (ICLM) is a rare and aggressive form of sarcoma within the retroperitoneum. Surgery is the mainstay of treatment, with no consensus on the benefit of chemoradiotherapy in the neo/adjuvant setting. This study aims to describe the natural history of a chemotherapy-naive ICLM treated in a tertiary cancer centre and to explore potential directions to improve oncological outcome. Materials and methods A prospective database was used to identify patient demographics, clinicopathological variables and oncological outcomes in 30 patients who underwent surgical resection in our institution for primary non-metastatic ICLM between 2003 and 2018. Results There was no 90-day mortality. With a median follow-up time of 70.0 months (95% CI 52.6–87.4), 5/30 patients (16.7%) developed local recurrence while 11/30 (36.7%) developed distant metastatic disease. 1 patient (3.3%) developed both local and distant recurrence. Median overall survival of our cohort was 41.0 months (95% CI 33.6–48.4) and 5-year overall survival rate was 32.1%. Multivariate survival analysis using the Cox proportional hazard model identified tumour grade and blood loss of more than 600 mL as key prognostic factors in our model. Conclusion Management of ICLM should be centralised in high-volume sarcoma centres with expertise in the management of retroperitoneal sarcomas. Integration of tumour biology with a concerted effort to conduct conclusive multi-centre phase III in histological and molecularly defined sarcoma subgroups is necessary to improve patient outcome. We eagerly await the results of STRASS 2 study to gain more insights to the efficacy of neoadjuvant chemotherapy on patient prognosis.

Intraoperative radiotherapy (IORT) can be applied for locally advanced tumors and expected or unavoidable R1 situations combined with surgical resection. The aim is to improve local tumor control and long-term survival. The indications are primary and recurrent intra-abdominal and retroperitoneal tumors. This study aimed to evaluate own data and experiences with IORT combined with surgical visceral resection.Patients who underwent IORT combined with abdominal tumor resection in the Department of General and Visceral Surgery at the University Medical Center Freiburg between January 2008 and December 2018 were included in this study. The results were retrospectively evaluated regarding short-term and long-term outcomes.The most frequent indications for IORT were sarcoma followed by rectal and anal cancers. The median IORT dose used was 15 Gy (range 8-19 Gy). With a median comprehensive complication index (CCI) of 11.9, complications occurred in 24% of patients (Dindo-Clavien ≥ °III). The 90-day mortality was 0%. Especially in recurrent anal cancer the local control after 1 year was insufficient despite R0 resection.In this cohort of patients IORT could be applied with acceptable morbidity. Nevertheless, the indications and patient selection are critical factors for carrying out the treatment. The effect of IORT to improve local tumor control and long-term survival should be evaluated in further studies.HINTERGRUND: Die intraoperative Radiotherapie (IORT) kann bei lokal weit fortgeschrittenen Tumoren und zu erwartender bzw. nicht vermeidbarer R1-Situation ergänzend zur chirurgischen Resektion eingesetzt werden. Ziel ist eine verbesserte lokale Tumorkontrolle und damit ein besseres Langzeitüberleben. Indikationen sind sowohl primäre intraabdominelle und retroperitoneale Tumoren als auch Rezidivtumoren. Im Rahmen der vorliegenden Arbeit werden die eigenen Erfahrungen mit der Durchführung einer IORT bei viszeralchirurgischen Resektionen zusammengefasst.Patienten, die von Januar 2008 bis Dezember 2018 eine IORT kombiniert mit abdomineller Tumorresektion in der Klinik für Allgemein- und Viszeralchirurgie des Universitätsklinikums Freiburgs erhalten hatten, wurden in diese Arbeit eingeschlossen und hinsichtlich Kurz- und Langzeitergebnisse evaluiert.Die häufigste Indikation zur Durchführung einer IORT stellten Sarkome gefolgt von Rektum- und Analkarzinomen dar. Die mediane angewandte Strahlendosis der IORT betrug 15 Gy (8–19 Gy). Bei einem medianen „comprehensive complication index“ (CCI) von 11,9 traten bei 24 % der Patienten Komplikationen (Dindo-Clavien ≥ °III) auf. Die 90-Tage-Mortalität betrug 0 %. Besonders für Analkarzinomrezidive war die lokale Kontrolle nach einem Jahr trotz R0-Resektion unzureichend.In unserem Patientenkollektiv war die IORT mit vertretbarer Morbidität einsetzbar. Dennoch sind Indikationsstellung und Patientenselektion kritische Punkte für die Durchführung der Behandlung. Der Effekt der IORT zur Verbesserung der lokalen Kontrolle und damit auch des Langzeitüberlebens sollte in weiteren Studien evaluiert werden.

BACKGROUND/AIM Recently, the concept of textbook outcome (TO) has emerged as a novel effort to develop a benchmark that reflects multiple domains of quality. The aims of the current study were to define TO for retroperitoneal sarcoma (RPS), evaluate the relationship of TO with hospital volume and assess the association of TO with overall survival. PATIENTS AND METHODS Patients who underwent resection for RPS diagnosed between 2004 and 2015 were identified in the National Cancer Database. The primary outcome was TO that was defined as: hospital length of stay 90 days from surgery, no readmission within 30 days and grossly negative margins. RESULTS Of the 11,032 patients analyzed, 54.0% had a TO. Among patients who had a TO, 57.8% were treated in high-volume hospitals. Undergoing surgery at high-volume centers was associated with a higher probability of a TO (p=0.009). TO were associated with significantly longer overall survival (p

Local retroperitoneal recurrence (RPR) after radical nephrectomy (RN) is rare in patients with renal cell carcinoma (RCC); however, it is associated with poor prognosis and lacks standard treatment. Our study aimed to assess oncological outcomes and prognostic factors of patients that underwent targeted therapy for RPR after RN, and to evaluate the role of presurgical targeted therapy in this context. This was a retrospective multicenter study of 85 patients with RPR treated with targeted therapy for RPR after RN (July 2008-October 2020). Clinical and pathological characteristics were reported using descriptive statistics. Cancer-specific survival (CSS) was examined using the Cox proportional hazards model. The median follow-up time was 50 months (95% confidence interval [CI]: 33.3-66.7) after the RPR diagnosis. The median CSS was 96 months in the presurgical targeted therapy followed by surgical resection group and 42 months (95% CI: 28.8-55.2) in the targeted therapy alone group (P = .0011). In multivariate analysis, International Metastatic RCC Database Consortium classification intermediate/poor risk, number of recurrence lesions and surgical resection were independent predictors of CSS. Presurgical targeted therapy may increase the feasibility of tumor resection for RPR after RN. Patients who underwent surgical resection following presurgical targeted therapy had better CSS than those treated with targeted therapy alone.

The role of en bloc vascular resection and reconstruction (EVRR) is controversial in colorectal adenocarcinoma (CRC), but well-established in retroperitoneal sarcoma (RPS). Sparse data exists regarding these complex procedures.Patients undergoing curative intent EVRR for advanced CRC and RPS between 2014 and 2021 at a tertiary centre were included. Morbidity, margins, recurrence, and survival were evaluated.24 patients underwent EVRR with 48 reconstructions (11 CRC and 13 RPS). For CRC, 100% of patients underwent Iliac system reconstructions. For RPS, inferior vena cava reconstructions were the most common (69.2%). There were 2 arterial and 1 venous graft thromboses. Primary graft patency was 89.4% arterial and 93.1% venous, while secondary patency was 100% arterial and 96.5% venous at last follow up. 1 venous and 1 arterial graft required reoperation for bleeding. There were no compromised limbs. Major complications occurred in 6 patients (25.0%) with no observed difference between CRC and RPS (OR 0.43 95%CI[0.60,3.19], P = 0.41). R1 margins occurred 1 CRC (90.9%) and 3 RPS (76.9%), with no R2 resections. All vascular resection margins were clear. There were 6 CRC (50%) and 4 RPS (33.3%) recurrences. Median recurrence time was 20.9 months for CRC and 'not yet reached' for RPS. Median follow-up was 19.4 months for CRC and 21.4 months for RPS.EVRR for locally advanced CRC or RPS is safe and achieves favorable R0 resection rates. CRC patients with major vascular invasion can still be considered for curative intent surgery. Larger cohorts with longer follow up are needed to assess oncologic outcomes.

Background Most retroperitoneal sarcoma (RPS) operations require combined multi-organ resection, and the proportion of unplanned reoperation is high. However, there are no relevant studies on reoperation for RPS. Methods Patients who underwent at least once unplanned reoperation at Shanghai Public Health Clinical Center, Fudan University, China, from August 2009 to December 2021 were retrospectively analyzed. The baseline characteristics, primary surgery, and reoperation information, postoperative complications, and survival were analyzed. Results A total of 51 patients were included. Among them, 21 (41.2%) were male and 30 (58.8%) were female. The median age was 51 (interquartile range [IQR], 49-63) years. Most (88.3%) had a history of abdominal surgery. Dedifferentiated liposarcoma, well-differentiated liposarcoma, leiomyosarcoma, and others accounted for 50.9%, 21.6%, 15.7%, and 11.8%, respectively. The conditions of the primary operation were as follows: 35 (68.6%) patients achieved complete surgical resection, 48 patients had combined organ resection, and a median of 3 (IQR, 2–4) organs was removed, of which 5 (9.9%) were combined with pancreaticoduodenectomy. The median operative time was 330 (IQR, 245–440) min, and the median estimated blood loss was 1500 (IQR, 500–2600) ml. The median postoperative hospital stay was 42 (IQR, 23–82) days. For reoperation, the most common reasons were bleeding (31.3%), complications related to intestinal anastomosis (27.4%), and intestinal perforation (19.9%). The mortality rate after reoperation was 39.2% (20/51). Twelve (23.5%) patients underwent reoperation at least twice. Conclusions Unplanned reoperation among retroperitoneal sarcoma correlates with established measures of surgical quality.

Retroperitoneal sarcoma (RPS) is a rare malignancy which can be difficult to manage due to the variety of clinical behaviors. In this study, we aimed to develop a parametric modeling framework to quantify the relationship between postoperative dynamics of several biomarkers and overall/progression-free survival of RPS. One hundred seventy-four patients with RPS who received surgical resection with curative intent at the Peking University Cancer Hospital Sarcoma Center were retrospectively included. Potential prognostic factors were preliminarily identified. Longitudinal analyses of body mass index (BMI), serum total protein (TP), and white blood cells (WBCs) were performed using nonlinear mixed effects models. The impacts of time-varying and time-invariant predictors on survival were investigated by parametric time-to-event (TTE) models. The majority of patients experienced decline in BMI, recovery of TP, as well as transient elevation in WBC counts after surgery, which significantly correlated with survival. An indirect-response model incorporating surgery effect described the fluctuation in percentage BMI. The recovery of TP was captured by a modified Gompertz model, and a semimechanistic model was selected for WBCs. TTE models estimated that the daily cumulative average of predicted BMI and WBC, the seventh-day TP, as well as certain baseline variables, were significant predictors of survival. Model-based simulations were performed to examine the clinical significance of prognostic factors. The current work quantified the individual trajectories of prognostic biomarkers in response to surgery and predicted clinical outcomes, which would constitute an additional strategy for disease monitoring and intervention in postoperative RPS.

As the population ages, more elderly patients are receiving surgery for retroperitoneal sarcoma (RPS). However, high-quality data investigating associations between ageing and prognosis are lacking. Our study aimed to investigate whether ageing is associated with inferior short-term survival outcomes after RPS surgery.Patients undergoing surgery for primary RPS between 2008 and 2019 at two tertiary sarcoma centres were analysed. The primary outcome was 1-year mortality, and the primary explanatory variable was patient age, classified as:55, 55-64, 65-74 or 75+ years.The 692 patients undergoing surgery (mean age 60.8 ± 13.8 years) had a 1-year mortality rate of 9.4%, which differed significantly by age (p0.001), with rates of 7.2%, 6.9%, 8.7% and 22.8% for the55, 55-64, 65-74 and 75+ years groups, respectively. The distribution of causes of death also differed significantly by age (p = 0.023), with 22% and 28% of deaths in the 65-74 and 75+ years groups caused by post-operative complications, versus none in the55 and 55-64 years groups. On multivariable analysis, age of 75+ years (versus55 years) was a significant independent predictor of 1-year mortality [odds ratio (OR) 7.05, 95% confidence interval (CI) 2.63-18.9, p0.001]; no significant increase in risk was observed in the 55-64 (OR 0.72, 95% CI 0.28-1.87) or 65-74 (OR 0.89, 95% CI 0.37-2.15) years groups.Post-operative complications are an important cause of deaths in elderly patients. These findings are relevant to decision-making and counselling when surgery is considered for patients with RPS.

A 49-year-old Japanese man had a chief complaint of left hypochondrium pain, and a CT scan revealed a mass in the left retroperitoneal space. CT and MRI scans revealed a hemorrhagic component and surrounding fibrous tissues. FDG PET/CT images showed increased uptake in the peripheral rim of the mass, indicating a malignant tumor. The SUV max was 7.6. We surgically resected the mass. The pathological examination confirmed the diagnosis of chronic expanding hematoma. It is difficult to differentiate CEH from malignant tumors on imaging; this should be recognized as a diagnostic pitfall.

Retroperitoneal sarcoma (RPS) is a surgically manageable condition that can recur locally after complete macroscopical resection. Managing patients at high-volume specialized healthcare centers has positive effects on treatment outcome. The present study aimed to preoperatively, perioperatively, and postoperatively assess patients who underwent surgery for RPS.Consecutive surgical resections of RPS performed at a single healthcare center between January 2011 and December 2018 were investigated retrospectively. Histological, radiological, and clinical data were collected. In addition to local recurrence rate of patients with complex tumor resection, existing symptoms, adjuvant treatment type, and 5- year overall and disease-free survival rates were recorded and analyzed.Extensive complete tumor resection was performed in 25 (%100) patients operated in our clinic for retroperitoneal sarcoma between 2011-2018. The mean survival time in patients undergoing R0 resection was found to be significantly higher than that in patients undergoing R1 resection(p=0.001). No statistically significant difference was found between histological grading and histological types in terms of mean survival (p=0.63 p=0.36). There was no statistically significant difference in terms of mean survival between patients who did not receive additional therapy, received adjuvant chemotherapy, and those who received adjuvant chemotherapy and radiotherapy. (p = 0.342) CONCLUSION: Although extensive complete resection is the gold standard in the treatment of retroperitoneal sarcoma, the effect of adjuvant chemotherapy and radiation therapy is still under discussion. In our study, high mean survival rates were determined due to R0 resection, and the effect of tumor grade and histological subtype on survival was not observed.Adjuvant therapy, Overall survival, Retroperitoneal sarcoma, Surgical resection.Il sarcoma retroperitoneale (RPS) è una condizione gestibile chirurgicamente che può ripresentarsi localmente dopo la resezione macroscopica completa. La gestione dei pazienti in centri sanitari specializzati ad alto volume ha effetti positivi sull’esito del trattamento. Il presente studio mira a valutare preoperatorio, perioperatorio e followup di pazienti sottoposti a intervento chirurgico per RPS. Sono state investigate retrospettivamente le resezioni chirurgiche consecutive di RPS eseguite in un unico centro sanitario tra gennaio 2011 e dicembre 2018. Sono stati raccolti dati istologici, radiologici e clinici. Oltre al tasso di recidiva locale dei pazienti con resezione tumorale complessa, sono stati registrati e analizzati i sintomi esistenti, il tipo di trattamento adiuvante e i tassi di sopravvivenza globale e libera da malattia a 5 anni. Risultati: un’ampia resezione completa del tumore è stata eseguita in 25 (% 100) pazienti operati nella nostra clinica per sarcoma retroperitoneale tra il 2011 e il 2018. Il tempo medio di sopravvivenza nei pazienti sottoposti a resezione R0 è risultato essere significativamente più alto rispetto a quello nei pazienti sottoposti a resezione R1 (p = 0,001). Nessuna differenza statisticamente significativa è stata trovata tra la classificazione istologica e tipi istologici in termini di sopravvivenza media (p = 0,63 p = 0,36). Non c’era alcuna differenza statisticamente significativa in termini di sopravvivenza media tra i pazienti che non hanno ricevuto terapia aggiuntiva, che hanno ricevuto chemioterapia adiuvante e quelli che hanno ricevuto chemioterapia e radioterapia adiuvanti (p = 0,342) In conclusione: sebbene un’ampia resezione completa sia il gold standard nel trattamento del sarcoma retroperitoneale, l’effetto della chemioterapia adiuvante e della radioterapia è ancora in discussione. Nel nostro studio, sono stati determinati tassi di sopravvivenza medi elevati a causa della resezione R0 e non è stato osservato l’effetto del grado di tumore e del sottotipo istologico sulla sopravvivenza.

Background: Prophylactic ureteral catheters placement (PUCP) was advocated as an effective strategy for decreasing ureteral morbidities in colorectal surgeries. However, whether it should be routinely used prior to primary retroperitoneal liposarcoma (PRLS) surgeries remains unknown. Methods: It was a retrospective study, conducted at a tertiary sarcoma center. Medical records of patients with PRLS undergoing surgeries from January 2015 through December 2018 were reviewed. Primary endpoint was the rate of ureteral morbidities during and after retroperitoneal liposarcoma resection procedures. Univariate and multivariate analyses determined risk factors associated with ureteral injury (UI) in patients undergoing surgeries. Results: A total of 55 patients of PRLS were included. Fourteen (25.5%) patients underwent PUCP, with 1 UI (7.1%) identified. In 41 patients with no PUCP, 15 (36.6%) exhibited UIs during and post surgeries. There were significant improvements of UIs in group PUCP, compared with patients without PUCP ( P

Background Soft-tissue sarcomas are rare malignancies that consist of many different histologic subtypes and arise in various locations in the body. In patients with lung metastases from retroperitoneal sarcomas, the long-term outcomes and prognostic factors are unknown. This study is a retrospective review of patients undergoing pulmonary metastasectomy for retroperitoneal sarcoma metastases at one institution, with the purpose of determining prognostic factors and clinical outcomes. Methods This is a single-center, retrospective cohort study of patients undergoing pulmonary metastasectomy for lung metastases from various sarcomas at Okayama University Hospital from January 2006 to December 2018. The Kaplan-Meier method and log-rank test were used for the analyses, and cut-off values of continuous variables were determined by a receiver operating characteristic curve analysis. Results Twenty-four patients underwent the first pulmonary metastasectomy for lung metastases from retroperitoneal sarcoma in our hospital. Leiomyosarcoma was the most common histologic subtype of retroperitoneal sarcoma (79.2%, n = 19). Median overall survival was 49.9 months, and the 3-year and 5-year survival rates after the first pulmonary metastasectomy were 62.5% and 26.4% respectively. In univariate analysis, age ≥56 years, disease-free interval < 15 months, and size of metastasis (≥ 27 mm) were associated with poor survival. Conclusion Pulmonary metastasectomy can be considered as an effective management strategy in retroperitoneal sarcoma patients with lung metastases in appropriately selected cases, just as it is for other sarcomas.

In this study, patients, who underwent excision of retroperitoneal mass following chemotherapy for testicular cancers from 2006 to 2016, were studied and followed till 2021. The clinical and oncological outcomes were measured. Among 338 patients, who were treated for TC during the entire study period, 38 (11.2%) underwent excision of the residual retroperitoneal mass. The mean age of these patients was 26.9±6.3 years. The majority were stage 3 testicular cancer. Complete resection with negative microscopic margins was achieved in the majority of cases i.e. 31 (81.6%). Damage to the collateral structures was seen in 12 (31.6%) cases. On histopathological examination, teratoma was seen in 18 (47.4%) of the cases followed by necrosis in 10 (26.3%). Complications were recorded in 12 (31.5%) cases, most were low grades. At five years of follow-up, 19 (50%) were disease-free, 25 (65.8%) were alive, and 9 (23.6%) were lost to follow-up. Five-year survival rates are lower than standard template-based retroperitoneal dissection, however, complications rates are comparable. Such complex surgeries should only be performed in high-volume centres. Key Words: Testicular neoplasms, Lymph node excision, Seminoma, Germ cell and embryonal.

BackgroundVitreoretinal lymphomas are difficult to diagnose due to their insidious onset and inaccessible focal points. Natural killer/T-cell derived malignancies are rare as intraocular lymphomas and usually have a rapid progression and a poor prognosis. Therefore, it is essential to make a definite diagnosis, especially differentially with B-cell-derived lymphomas, which account for most cases of vitreoretinal lymphomas.Case presentationThis case report describes a 55-year-old female reporting a 10-month history of painless decline in her vision of the right eye. Optical coherence tomography of the patient revealed hyperreflective nodules and irregular humps in the retinal pigment epithelium layer. The right vitreous was aspirated for diagnostic assessment, revealing an interleukin-10 level of 39.4 pg/mL and an interleukin-10/interleukin-6 ratio of 1.05. The right vitreous humor was positive for Epstein–Barr virus DNA. Upon a systemic examination, a high metabolic nodule was found in the retroperitoneal area and proven to be positive for Epstein–Barr virus-encoded mRNA, CD2, CD3ε, TIA-1, and Ki-67. Considering the homology of the two lesions, the patient was diagnosed with metastatic vitreoretinal lymphoma secondary to retroperitoneal extranodal natural killer/T-cell derived lymphoma. The patient received systemic chemotherapy and regular intravitreal injections of methotrexate. Her visual acuity of the right eye had improved from 20/125 to 20/32 at the latest follow-up. No new lesions were found.ConclusionsA definitive diagnosis of vitreoretinal lymphoma is challenging. On some occasions in which pathological evidence is missing, the available examination results and clinical observations must be comprehensively considered. This study herein summarized pertinent pieces of literature and reports and reviewed available practicable methods to make a definitive diagnosis of intraocular extranodal natural killer/T-cell lymphoma, which was particularly distinct from the common diffuse large B-cell lymphomas.

Background Retroperitoneal liposarcoma (RPLS) is a specific soft tissue sarcoma with a high recurrence rate. The short isoform of transient receptor potential cation channel subfamily M member 2 (TRPM2-S) plays an important role in the regulation of reactive oxygen species (ROS). However, the association between TRPM2-S and RPLS and its underlying mechanisms remains unclear. Methods The expression of both TRPM2-S and TRPM2-L in RPLS tissues was verified by kimmunohistochemistry (IHC). The regulation on Ca2+ influx by TRPM2-S was evaluated by Fluo-4 AM staining. The effect of TRPM2-S on cell proliferation and apoptosis was tested by 5-Ethynyl-2′-deoxyuridine (EdU) staining and Flow cytometry respectively. The level of cellular ROS was assessed by the DCFH-DA probe. Different concentrations of H2O2 were used to provide oxidative stress on RPLS cells. The underlying mechanisms were further explored by Western blotting. Results The IHC assays showed that TRPM2-S, but not TRPM2-L, was prognostic in RPLS. Low TRPM2-S level was associated with poor disease-free survival (DFS). Calcium influx signal intensity was significantly decreased under TRPM2-S overexpression, which resulted in a decrease in the levels of FOXO3a and PTEN. Correspondingly, the levels of pERK, pAKT, pP65, pGSK-3β, Bcl-2, and β-catenin were upregulated, and cellular ROS was gently increased under TRPM2-S overexpression. Moreover, TRPM2-S slightly promoted cell proliferation and inhibited apoptosis of RPLS cell lines under normoxia, but largely increased apoptosis rates under oxidative stress. The cleaved caspase3 was significantly upregulated by TRPM2-S overexpression under oxidative stress. N-Acetyl-l-cysteine (NAC), a small molecule antioxidant, could largely rescue RPLS cells from the apoptosis induced by H2O2. Conclusion TRPM2-S exerts Janus-faced effects in RPLS by increasing the ROS levels via inhibition on FOXO3a, which promotes cell proliferation under normoxia but induces apoptosis under oxidative stress.

EORTC-62092 (STRASS) was a phase 3, randomized study that compared surgery alone versus surgery plus neoadjuvant radiotherapy (RT) for retroperitoneal sarcomas. RT was not associated with improved abdominal recurrence-free survival, the primary outcome measure, although on subanalysis, there may have been benefit for well-differentiated (WD) liposarcoma. This study investigated the real-world use and outcomes of RT (neoadjuvant and adjuvant) for the management of retroperitoneal liposarcoma.We queried the National Cancer Database (NCDB) (2004-2017) for patients with nonmetastatic, primary retroperitoneal liposarcoma treated with resection with or without RT (n = 3911). Patients were stratified by treatment type and histology [WD (n = 2252), dedifferentiated (DD) (n = 1659)]. Propensity score (PS) matching was used before comparison of treatment groups. Overall survival (OS) was the primary outcome measure.Median follow-up time was 4.1 years, and median OS was 10.7 years. There was no association between RT and OS for either WDLPS or DDLPS cohorts. We performed a subgroup analysis of neoadjuvant RT only, similar to STRASS. For WDLPS after PS matching (n = 208), neoadjuvant RT was not associated with OS (hazard ratio [HR] 1.01, p = 0.0523) but was associated with longer postoperative hospital stay (p = 0.012). For DDLPS after PS matching (n = 290), neoadjuvant RT was not associated with OS (HR 1.02, p = 0.889). For both WD-LPS and DD-LPS, utilization of neoadjuvant RT was associated with treatment at high-volume (≥ 10 cases/year) and academic/network facilities.For primary retroperitoneal liposarcoma treated with surgical resection, radiotherapy was not associated with an overall survival benefit in this propensity-matched, adjusted analysis of the NCDB.

The main indication for kidney autotransplantation is ureteric disease, although it is also performed to treat renovascular diseases or neoplasms, such as complex intrasinusal kidney tumors or in patients with a solitary kidney. Only a few cases of kidney autotransplantation in the context of resection of complex retroperitoneal masses have been reported in the literature., [Case Presentation] We report the case of a 26-year-old man with history of nonseminomatous germ cell tumor who had undergone a left radical orchiectomy 3 months earlier. Follow-up computed tomography revealed a residual retroperitoneal postchemotherapy mass involving the renal hilum. It was surgically removed via en bloc resection and bench ex vivo nephron-sparing surgery, and subsequently autotransplantation, thereby avoiding the necessity of nephrectomy and the resulting risk of chronic kidney disease. The pathology of the excised specimen demonstrated mixed germ cell tumor, composed of immature teratoma and yolk sac tumor, and confirmed tumor-free margins., [Conclusions] This technique should be taken into account in selected patients as an alternative to radical nephrectomy when a retroperitoneal tumor is unresectable using standard surgical techniques or when a radical nephrectomy is considered, especially in patients with chronic kidney disease or solitary kidney, or in young patients who will potentially need nephrotoxic chemotherapy.

Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS.An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor.Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS.Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

Castleman disease is a rare benign lymphoproliferative disorder that includes a spectrum of distinct histopathological entities. The differential diagnosis of Castleman disease is broad and includes lymphomas, HIV-related lymphadenopathy, autoimmune disorders, and inflammatory liposarcoma. When Castleman disease occurs in the retroperitoneum, the distinction from the inflammatory variant of well-differentiated liposarcoma can be very challenging in small biopsies. Herein we report a case of Castleman disease that presented as a retroperitoneal mass and expressed MDM2 and CDK4 by immunohistochemistry. To our knowledge, this is the first report of Castleman disease staining positively for MDM2/CDK4, and it underscores how immunohistochemistry can potentially serve as a pitfall when differentiating this rare entity from retroperitoneal sarcomas.

Retroperitoneal and abdominopelvic sarcomas are rare heterogeneous malignancies. The only therapy proven to improve disease-free survival (DFS) is R0/R1 surgical resection. We sought to analyze whether additional factors such as radiation and systemic therapy were associated with DFS and abdominal recurrence-free survival (RFS).Retrospective review of adults (≥18) with resectable abdominopelvic and retroperitoneal sarcomas who underwent intent-to-cure surgery at a high-volume tertiary referral center between 1998 and 2015. The main outcome measures were DFS and abdominal RFS.Overall, 159 patients met the criteria for inclusion. Median follow-up was 4.8 years (range 0.1-18.9 years). The most common histology was liposarcoma (49%). Systemic therapy was administered to 48% of patients and was not associated with improved outcomes. The neoadjuvant radiotherapy group (11%) had improved adjusted DFS (5.46 years, 95% CI [3.68, 7.24] vs. 3.1 years, 95% CI [2.48, 3.73]) and abdominal RFS (6.14 years, 95% CI [4.38, 7.89] vs. 3.22 years, 95% CI [2.61, 3.84]). The adjuvant radiotherapy group (19%) had no improvement.In a cohort of patients undergoing resection for retroperitoneal or abdominopelvic sarcoma, neoadjuvant radiation improved DFS and abdominal RFS. A follow-up of over three years was needed to appreciate a difference in outcomes.

Herein we provide a review of intravascular ultrasound (IVUS) and its ability to assist in the evaluation and surgical management of advanced retroperitoneal, genitourinary tumors.Advanced retroperitoneal tumors such as advanced renal cell carcinoma, bulky retroperitoneal lymphadenopathy associated with advanced testicular carcinoma, large adrenal tumors, and retroperitoneal sarcomas can invade, compress, or distort vascular anatomy making surgical resection challenging and high risk. Intravascular ultrasonography is commonly used by vascular and cardiothoracic surgery to provide a real time assessment of vascular invasion, compression, and aberrant anatomy to assist with pre-operative and/or intraoperative decision-making. However, the application of this technology to assist with cancer surgery has been limited. The use of intravascular ultrasound prior to radical, extirpative, retroperitoneal surgery involving large vessels can aid in the planning and execution of such challenging operations.

Palbociclib has been evaluated in early phase trials for well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS) patients, with reported median progression-free survival (PFS) of 18 weeks. Here, we report on real-world use and surgical outcomes associated with palbociclib treatment. We retrospectively reviewed 61 consecutive patients with retroperitoneal WDLPS (n = 14) or DDLPS (n = 47) treated with palbociclib monotherapy between 1 March 2016 and 28 February 2021 at The University of Texas MD Anderson Cancer Center. At palbociclib initiation, median age was 64 (interquartile range [IQR] 56-72). In WDLPS and DDLPS cohorts, the median number of prior systemic treatments was 0 (IQR 0-0) and 2 (IQR 0-4), respectively. Median number of prior surgeries was 2 (WDLPS IQR 1-2.75) and 2 (DDLPS IQR 1-3). Median PFS was 9.2 (WDLPS IQR 3.9-21.9) and 2.6 months (DDLPS IQR 2.0-6.1), with median time on treatment of 7.4 months (WDLPS IQR 3.5-14.2) and 2.7 months (DDLPS IQR 2.0-5.7). Twelve patients ultimately underwent surgical resection. Resections were macroscopically complete (R0/R1) in half (n = 6/12), among whom only one patient experienced relapse after resection (median follow-up 7.5 months). All patients who underwent macroscopically incomplete resections progressed after surgery with median time to progression of 3.3 months (IQR 2.3-4.4). Surgery after palbociclib treatment was not associated with improved overall survival. Efficacy of palbociclib monotherapy for patients with advanced WDLPS and DDLPS is disappointing. While palbociclib may have been used to delay surgery, there was no clear benefit from treatment and few patients achieved prolonged tumor control.

Previous studies examining the incidence of omental metastasis in uterine serous carcinoma generally suffered from small sample size, retrospective observational design, and single-center setting. So far, there was no systematic review and meta-analysis available on this topic, we conducted this study to quantitatively synthesize the data relating to this topic.systematic review and meta-analysis.PubMed, Embase, and Web of Science were searched up until August 15, 2020. Two reviewers independently performed study selection, data extraction, and quality assessment. Iincidence of omental metastasis in uterine serous carcinoma.A total of 16 studies involving 1012 women with uterine serous carcinoma were included in this study. All the included studies were at low risk of bias, and the heterogeneity among them was low. The pooled incidence of overall omental metastasis, occult omental metastasis, and gross omental metastasis in uterine serous carcinoma were 18% (95% CI, 0.15-0.20), 6% (95% CI, 0.04-0.08), and 10% (95% CI, 0.08-0.13), respectively.Uterine serous carcinoma has a high tendency of omental metastasis. The main form of omentum involvement is gross metastasis. However, occult metastasis in the normal-looking omentum is also worthy of note.

Background: The European Organization for Research and Treatment of Cancer 22092-62092 STRASS trial failed to demonstrate the superiority of neoadjuvant radiotherapy (RT) over surgery alone in patients with retroperitoneal sarcoma. Therefore, an RT quality-assurance program was added to the study protocol to detect and correct RT deviations. The authors report results from the trial RT quality-assurance program and its potential effect on patient outcomes. Methods: To evaluate the effect of RT compliance on survival outcomes, a composite end point was created. It combined the information related to planning target volume coverage, target delineation, total dose received, and overall treatment time into 2 groups: non-RT-compliant (NRC) for patients who had unacceptable deviation(s) in any of the previous categories and RT-compliant (RC) otherwise. Abdominal recurrence-free survival (ARFS) and overall survival were compared between the 2 groups using a Cox proportional hazard model adjusted for known prognostic factors. Results: Thirty-six of 125 patients (28.8%) were classified as NRC, and the remaining 89 patients (71.2%) were classified as RC. The 3-year ARFS rate was 66.8% (95% confidence interval [CI], 55.8%-75.7%) and 49.8% (95% CI, 32.7%-64.8%) for the RC and NRC groups, respectively (adjusted hazard ratio, 2.32; 95% CI, 1.25-4.32; P = .008). Local recurrence after macroscopic complete resection occurred in 13 of 89 patients (14.6%) versus 2 of 36 patients (5.6%) in the RC and NRC groups, respectively. Conclusions: The current analysis suggests a significant benefit in terms of ARFS in favor of the RC group. This association did not translate into less local relapses after complete resection in the RC group. Multidisciplinary collaboration and review of cases are critical to avoid geographic misses, especially for rare tumors like retroperitoneal sarcoma.

Background Leiomyosarcoma originating from the renal vein (RVLMS) is extremely rare. RVLMS lacks specific clinical manifestations and specific imaging features. This article discusses the epidemiological characteristics and diagnostic difficulties of RVLMS, as well as imaging features, differential diagnosis, treatment strategy, and prognostic factors of this disease. Method A case of RVLMS at our center, and 55 cases from the literature based on the PubMed search. Results Total operation time was 224 min, and total blood loss during the surgery was 200 ml. Resected tumor was irregular in shape, with negative margins. On the 6th day after the operation, the drainage tube was removed, and the patient was discharged from the hospital. Postoperative pathological results confirmed the renal vein leiomyosarcoma: spindle cell sarcoma, diffuse severe atypia, S-100 (-), SMA ( +), desmin ( +), CD34 (−), CD99 ( +). Twenty-seven months after the surgery, the patient is alive, and without local recurrence or distant metastases. Conclusion Unspecific clinical manifestations and imaging features make the diagnosis of RVLMS difficult. Most patients are diagnosed intra-operatively or following postoperative pathology. Differential diagnosis with paraganglioma (PG) and retroperitoneal sarcoma (RPS) should be made. Early and complete resection is considered as the first choice of treatment, and whether to preserve the kidney is based on the patient's condition. RVLMS is highly malignant, and may recur locally or metastasize to distant locations; therefore, adjuvant therapy and regular follow-up should be carried out after surgery.

Resumo Os leiomiossarcomas de veia cava inferior são tumores raros, que representam menos de 0,7% de todos os leiomiossarcomas retroperitoneais. Eles são mais comuns em mulheres e causam quadros inespecíficos de dor abdominal crônica. Neste relato, apresentamos um caso de paciente do sexo feminino, de 53 anos de idade, com queixa de dor abdominal crônica periumbilical inespecífica com evolução há 8 meses, diagnosticada com leiomiossarcoma de veia cava inferior por angiotomografia computadorizada. A paciente foi tratada com ressecção completa do tumor e reconstrução da veia cava inferior, com interposição de prótese de dácron. O tratamento considerado padrão-ouro consiste na excisão cirúrgica completa, visto que esses tumores são resistentes a quimioterapia e radioterapia. O prognóstico desses pacientes está intimamente relacionado com a precocidade do diagnóstico, e, por isso, é de grande relevância o conhecimento dessa doença como diagnóstico diferencial de dor abdominal crônica e inespecífica por cirurgiões vasculares e cirurgiões gerais. Abstract Inferior vena cava leiomyosarcomas are rare tumors that account for less than 0.7% of all retroperitoneal leiomyosarcomas. They are more common in women and cause nonspecific chronic abdominal pain. In this report, we present the case of a 53-year-old female patient complaining of chronic nonspecific periumbilical abdominal pain with initial onset 8 months previously who was diagnosed with inferior vena cava leiomyosarcoma by computed tomography angiography. The patient was treated with complete resection of the tumor and reconstruction of the inferior vena cava with interposition of a Dacron prosthetic graft. The treatment considered the gold standard consists of complete surgical excision, because these tumors are resistant to chemotherapy and radiotherapy. The prognosis of these patients is closely related to early diagnosis. Therefore, it is very important that vascular and general surgeons know that this disease is a possible differential diagnosis of chronic abdominal pains.

Oncovascular surgery is a new term used to define tumor resection with simultaneous reconstruction of the great vessels when the tumor infiltrates or firmly adheres to such vessels. The benefit of oncovascular surgery has been widely described in patients with hepato-biliary-pancreatic cancers, retroperitoneal soft tissue sarcoma, and in other areas of gynecologic oncology, such as the lateral compartment of the pelvis, retroperitoneum, and hepato-biliary-pancreatic region, with an increase in complete resections and without increasing the morbidity and mortality rates. In the latter decades of the past century, several advances and accumulating scientific evidence led gynecologic oncologists to perform more thorough cytoreductive surgeries that included multivisceral resections. But to our knowledge, published studies on the frequency and relevance of vascular surgery in gynecological oncology are scarce. Gynecologic oncologists still do not receive formal training in vascular surgery and additionally, with the current reduction in experience with pelvic and para-aortic lymphadenectomy, as well as other types of radical abdominal and pelvic surgeries, trainees will encounter fewer vascular injuries and the opportunity to deal with a variety of management types required. Well-organized collaboration between each subspecialty with a multidisciplinary approach and adequate pre-operative planning are pivotal. The aim of this review is to pave the way towards the understanding that patients with suspicion of great vessels' infiltration or encasement by tumor require personalized and specialized treatment with the need to form an oncovascular surgery team, and that it is necessary for gynecologic oncology surgeons to take a step forward in surgical training.

Not applicable

To review current knowledge and recent advances in retroperitoneal sarcoma management.Surgery, radiotherapy, and medical treatments of retroperitoneal sarcomas should take into account the peculiarities of each histotype and the unique anatomical site. Surgery remains the mainstay of treatment and the only chance of cure for these diseases. In low-grade retroperitoneal sarcomas, like well differentiated liposarcoma, where the leading cause of death is dominated by local rather than distant relapses, treatment of the primary tumor encompasses extended surgery with multiorgan resection and evaluation of preoperative radiotherapy. Conversely, surgery is usually more conservative and without radiotherapy in those retroperitoneal sarcomas, such as leiomyosarcoma, characterized by a high risk of metastatic spread that prompted also the evaluation of neoadjuvant, histotype-driven chemotherapy. Surgery might have a role also for relapsed disease, despite long-term disease control probability declines at each recurrence. In advanced stages, anthracyclines still retain a key role and all medical treatment strategies should follow the specific chemosensitivity of each histotype to improve patient's outcomes.The rarity and heterogeneity in biological behavior and clinical presentation of retroperitoneal sarcomas deserves a multidisciplinary and histotype-driven treatment at all stages of the disease to be performed in highly specialized centers.

Cilj: Castelmanova bolest rijetko je oboljenje koje karakterizira benigna hiperplazija limfnih čvorova. Glavni je cilj prikazati Castelmanovu bolest kao mogući uzrok retroperitonealne tvorbe u pedijatrijskoj populaciji. Prikaz slučaja: Na Zavod za hematologiju, onkologiju i kliničku genetiku Klinike za pedijatriju Kliničkog bolničkog centra Rijeka zaprimljen je petnaestogodišnji dječak radi verifikacije ekspanzivne tvorbe u području burze omentalis, koja je utvrđena ultrazvukom prilikom obrade recidivirajućeg povraćanja. Naime, dječak je deset dana pred prijam svakodnevno povraćao ujutro nakon doručka u tri do četiri navrata. Ultrazvučno je bila prikazana dobro ograničena tvorba promjera 4 x 3 cm između duodenuma i pankreasa. Kompjutoriziranom tomografijom prikazala se tvorba koja se utiskivala u želudac bez znakova infiltracije okolnih struktura. Prema karakteristikama tvorbe vidljivih magnetskom rezonancijom zaključilo se da se radi o solitarnoj benignoj tvorbi. Učinjena je iglena punkcija pod kontrolom endoskopskog ultrazvuka, a na temelju citološkog nalaza postavila se klinička sumnja na Castelmanovu bolest hijalino-vaskularne varijante. Napravljena je kirurška ekstirpacija tvorbe što je ujedno i standard liječenja unicentrične Castelmanove bolesti. Patohistološka analiza potvrdila je radnu dijagnozu unicentrične Castelmanove bolesti miješane varijante. Poslijeoperacijski tijek prošao je uredno i dječak je otpušten kući dobrog općeg stanja. Na redovnim kontrolama nije bilo znakova recidiva osnovne bolesti. Zaključak: Iako je Castelmanova bolest rijetka, pogotovo retroperitonealne lokalizacije i u pedijatrijskoj populaciji, treba ju uvrstiti u diferencijalnu dijagnozu pri pronalasku tumorske tvorbe na toj lokalizaciji., Aim: Castelman's disease is a rare condition characterized by benign lymph node hyperplasia. The aim of this paper is to present Castelman's disease as a possible cause of retroperitoneal mass in the pediatric population. Case report: A fifteen-year-old boy was admitted to the Department of Pediatric Hematooncology for verification of an expansive formation in the area of omental bursa. The formation was detected by ultrasound during diagnostics due to recurrent vomiting. The boy complained of vomiting during ten days before admission, three to four times daily, usually after breakfast. Ultrasound showed a well-limited formation 4 x 3 centimeters in diameter located between the duodenum and pancreas. Computed tomography confirmed localisation of the tumor showing no signs of infiltration of surrounding structures and magnetic resonance imaging reported benign characteristics. Endoscopic ultrasound guided needle biopsy was preformed and a clinical presumption of a hyaline-vascular variant Castelman's disease was made. Surgical extirpation was performed. Complete tumor resection is a standard treatment for unicentric Castelman's disease. The pathological analysis confirmed the diagnosis of unicentric mixed variant Castelman's. Postoperative recovery went smoothly and the boy was discharged home in good general condition.There were no signs of recurrence of the underlying disease at regular check-ups. Conclusion: Although Castelman's disease is rare, especially localized retroperitoneally and in pediatric population, it should be included in the differential diagnosis when considering retroperitoneal tumorous formations.

Background Reports on the epidemiology and mortality of retroperitoneal soft tissue sarcoma (RSTS) in Switzerland are scarce. This study investigates the incidence and outcomes of surgically treated RSTS inpatients in Switzerland depending on the hospital type and size. Methods Data from the Swiss Federal Statistical Office were used to conduct a retrospective analysis of all RSTS inpatients and hospitalizations in Switzerland between 2005 and 2015. RSTS was identified by the code C48.x of the International Classification of Diseases (ICD-10). Sarcoma centers were identified by the annual total number of sarcoma patients (> 50 patients/year). The analysis of yearly incidence, age distribution as well as in-hospital complication and mortality was performed for non- and surgical-treated patients. A centralization of treating sarcoma patients was analyzed by the trend of hospitalizations in sarcoma centers and high-volume hospitals. Results During 2005–2015, 2.801 hospitalizations (1651 patients) were admitted to Swiss hospitals with the primary diagnosis of a RSTS. The yearly number of RSTS patients and the incidence (1.91/100.000) stayed constant within these 11 years. There were five sarcoma centers. We saw a clear trend of RSTS patients being treated (especially surgically) in centers over the 11 years. The complication rate of surgical-treated patients was higher in sarcoma centers (55% vs. 40%), though the overall mortality rate was lower (3.2% vs. 9.1%). Conclusion Centralization of RSTS treatment to certified sarcoma centers leads to a lower overall mortality rate and thus is highly recommended.