Percutaneous cryoablation for desmoid fibromatosis: initial experience at a UK centre.

AIM: To report the first UK experience of cryoablation in desmoid fibromatosis (DF) with particular focus on technique, safety, and efficacy. MATERIALS AND METHODS: Patients were selected at multidisciplinary tumour board meetings at a specialist cancer hospital. Radiation dose, procedure duration, and number of cryoprobes were compared for small versus large tumours (>10 cm long axis). Response at magnetic resonance imaging (MRI) was evaluated using different criteria, and percentage agreement with clinical response as assessed in oncology clinic calculated. RESULTS: Thirteen procedures were performed in 10 patients (eight women, median age 51 years, IQR 42-69 years) between February 2019 and August 2021. Procedures for large tumours had higher radiation dose (2,012 ± 1,012 versus 1,076 ± 519 mGy·cm, p=0.048) used more cryoprobes (13 ± 7 versus 4 ± 2, p=0.009), and were more likely to have residual unablated tumour (38 ± 37% versus 7.5 ± 10%, p=0.045). Adverse events were minor apart from one transient radial nerve palsy. Eight of 10 patients had symptomatic benefit at clinical follow-up (median 353 days, IQR 86-796 days), and three started systemic therapy mean 393 days later. All patients who had complete ablation demonstrated symptomatic response, with no instances of repeat treatment, recurrence, or need for systemic therapy during the study period. All progression occurred outside ablation zones. CONCLUSION: Cryoablation for symptomatic DF is a reproducible technique with low, transient toxicity, where one or two treatments can achieve a meaningful response. Where possible, the ablation ice ball should fully cover DF tumours.

Management of meningeal solitary fibrous tumors/hemangiopericytoma; surgery alone or surgery plus postoperative radiotherapy?

INTRODUCTION: A meningeal solitary fibrous tumor (SFT), also called hemangiopericytoma, is a rare mesenchymal malignancy. Due to anatomic constrains, even after macroscopic complete surgery with curative intent, the local relapse risk is still relatively high, thus increasing the risk of dedifferentiation and metastatic spread. This study aims to better define the role of postoperative radiotherapy (RT) in meningeal SFTs. PATIENTS AND METHODS: A retrospective study was performed across seven sarcoma centers. Clinical information was retrieved from all adult patients with meningeal primary localized SFT treated between 1990 and 2018 with surgery alone (S) compared to those that also received postoperative RT (S + RT). Differences in treatment characteristics between subgroups were tested using independent samples t-test for continuous variables and chi-square tests for proportions. Local control (LC) and overall survival (OS) rates were calculated as time from start of treatment until progression or death from any cause. LC and OS in groups receiving S or S + RT were compared using Kaplan-Meier survival curves. RESULTS: Among a total of 48 patients, 7 (15%) underwent S and 41 (85%) underwent S + RT. Median FU was 65 months. LC was significantly associated with treatment. LC after S at 60 months was 60% versus 90% after S + RT (p = 0.052). Furthermore, R1 resection status was significantly associated with worse LC (HR 4.08, p = 0.038). OS was predominantly associated with the mitotic count (HR 3.10, p = 0.011). CONCLUSION: This retrospective study, investigating postoperative RT in primary localized meningeal SFT patients, suggests that combining RT to surgery in the management of this patient population may reduce the risk for local failures.

Overview of malignant soft-tissue sarcomas of the limbs.

Although soft-tissue masses are common, sarcomas are rare malignant neoplasms showing variable mesenchymal differentiation and can occur at any anatomical site. Limb soft-tissue sarcomas (STS) are rare, but often lethal tumours. Although there are scores of historical pathological subtypes, this article will deal with the commonest: liposarcoma, leiomyosarcoma (LMS), undifferentiated pleomorphic sarcoma (UPS), synovial sarcoma, myxofibrosarcoma, malignant peripheral nerve sheath tumour (MPNST), epithelioid sarcoma, alveolar rhabdosarcoma, angiosarcoma and radiation-induced sarcoma (RIS). Following a review of >4,000 adult patients with limb sarcoma from our specialist soft-tissue tumour database, we summarise the literature and their imaging findings, with emphasis on radiological hallmarks that can aide in diagnosis and management. Increased awareness of sarcoma when challenged with a new mass in the extremity can ensure timely and appropriate treatment.

18F-PSMA-1007 multiparametric, dynamic PET/CT in biochemical relapse and progression of prostate cancer.

OBJECTIVES: Aim of the present analysis is to investigate the biodistribution and pharmacokinetics of the recently clinically introduced radioligand 18F-PSMA-1007 in patients with biochemical recurrence or progression of prostate cancer (PC) by means of multiparametric (dynamic and whole-body) PET/CT. METHODS: Twenty-five (25) patients with PC biochemical relapse or progression (median age = 66.0 years) were enrolled in the analysis. The median PSA value was 1.2 ng/mL (range = 0.1-237.3 ng/mL) and the median Gleason score was 7 (range = 6-10). All patients underwent dynamic PET/CT (dPET/CT) scanning (60 min) of the pelvis and lower abdomen as well as whole-body PET/CT with 18F-PSMA-1007. PET/CT assessment was based on qualitative evaluation, SUV calculation, and quantitative analysis based on a two-tissue compartment model and fractal analysis. RESULTS: 15/25 patients were PET-positive. Plasma PSA values in the 18F-PSMA-1007 positive group were higher (median = 3.6 ng/mL; range = 0.2-237.3 ng/mL) than in the 18F-PSMA-1007 negative group (median value = 0.7 ng/mL; range = 0.1-3.0 ng/mL). Semi-quantitative analysis in the PC lesions demonstrated a mean SUVaverage = 25.1 (median = 15.4; range = 3.5-119.2) and a mean SUVmax = 41.5 (median = 25.7; range = 3.8-213.2). Time-activity curves derived from dPET/CT revealed an increasing tracer accumulation during the 60 min of dynamic PET acquisition into the PC lesions, higher than in the urinary bladder and the colon. Significant correlations were observed between 18F-PSMA-1007 uptake (SUV), influx, and fractal dimension (FD). CONCLUSIONS: 18F-PSMA-1007 PET/CT could detect PC lesions in 60% of the patients of a mixed population, including also patients with very low PSA values. Higher PSA values were associated with a higher detection rate. Dynamic PET analysis revealed an increasing tracer uptake during the dynamic PET acquisition as well as high binding and internalization of the radiofluorinated PSMA ligand in the PC lesions.

Diagnostic performance of MRI and histology in assessment of deep lipomatous tumours.

BACKGROUND: Deep lipomatous tumours can be benign lipomas or intermediate/locally recurring atypical lipomatous tumours (ALTs). Differentiating between these two entities clinically and radiologically is difficult. The aims of this study were to report a series of deep lipomatous tumours, comparing the clinical, radiological and pathological features of ALTs and lipomas; and to predict the likelihood of a lipomatous tumour being ALT based on anatomical site and MRI characteristics. METHODS: This was a retrospective review of patients with deep lipomatous tumours presenting over 6 years to a tertiary sarcoma centre, with preoperative MRI, and preoperative or postoperative histology including MDM2 gene analysis. Sensitivity, specificity, predictive values and accuracy in diagnosing ALT were calculated for MRI and histopathological features. RESULTS: Some 248 patients were included; 81 (32·7 per cent) had a final diagnosis of ALT. ALTs were larger than lipomas (median 19 versus 10 cm; P < 0·001); there was no ALT smaller than 5 cm. A tumour presenting in the lower limb was more likely to be an ALT than a lesion at any other site (48·4 versus 13·5 per cent; P < 0·001). In patients with lipomatous tumours at sites other than the lower limbs, MRI had a negative predictive value of 95 per cent for excluding ALT. CONCLUSION: Despite concern, most deep lipomatous tumours (nearly 70 per cent) are benign lipomas. Certain features imply that tumours are almost never ALT: smaller than 5 cm or located outside the lower limb with no suspicious characteristics on MRI. Tumours with these features might safely and confidently be managed outside tertiary sarcoma centres.

ANTECEDENTES: Los tumores lipomatosos profundos pueden ser lipomas benignos o tumores lipomatosos atípicos (atypical lipomatous tumour, ALT) con potencial de recidiva local/intermedia. Diferenciar estas dos entidades desde el punto de vista clínico es difícil. Los objetivos de este estudio fueron presentar una gran serie de tumores lipomatosos profundos, comparando las características clínicas, radiológicas y patológicas de los ALT y de los lipomas y predecir la probabilidad de que un tumor lipomatoso sea ALT según su localización anatómica y las características de la RNM. MÉTODOS: Revisión retrospectiva de pacientes con tumores lipomatosos profundos tratados en un centro terciario de sarcoma durante un período de 6 años, en los que se dispusiese de RNM preoperatoria y análisis MDM2 en el preoperatorio o postoperatorio. Se calculó la sensibilidad, la especificidad, el valor predictivo y la precisión diagnóstica de la RNM y de las características histopatológicas para el diagnóstico de ALT. RESULTADOS: Se incluyeron 248 pacientes, de los que en solo 81 (32,7%) se estableció un diagnóstico final de ALT. Los ALT fueron más grandes que los lipomas (19 versus 10 cm, P < 0,001) y no hubo ningún ALT de tamaño menor de 5 cm. Hubo una mayor probabilidad de que un tumor fuera ALT si se presentaba en las extremidades inferiores en comparación con cualquier otra localización (48,4% versus 13,5%, P < 0,001). En pacientes con tumores lipomatosos localizados en otros lugares que no fueran las extremidades inferiores, la RMN tuvo un valor predictivo negativo del 95,5% para excluir la ALT. CONCLUSIÓN: A pesar del recelo tradicional, la mayoría (70%) de los tumores lipomatosos profundos son lipomas benignos. Algunas características, como los tumores de menos de 5 cm y aquellos ubicados fuera de las extremidades inferiores sin características sospechosas por RNM, indican que los tumores casi nunca son ALT. Los tumores con esas características pueden tratarse de manera segura y con solvencia fuera de los centros de sarcomas terciarios. En casos seleccionados, puede ser útil la prueba genética MDM2 en la biopsia.

Patterns of disease relapse in primary extremity soft-tissue sarcoma.

BACKGROUND: Extremity soft-tissue sarcomas comprise a range of distinct histological subtypes. This study aimed to characterize the patterns of disease relapse in patients undergoing resection of primary extremity soft-tissue sarcoma. METHODS: All patients who had resection of primary extremity soft-tissue sarcoma at the Royal Marsden Hospital between January 2004 and January 2014 were identified from an institutional database. RESULTS: In the period examined, 556 patients underwent resection. The most common histological subtypes were undifferentiated pleomorphic sarcoma (169 patients, 30·4 per cent), well differentiated liposarcoma (63, 11·3 per cent), myxoid liposarcoma (62, 11·2 per cent), myxofibrosarcoma (54, 9·7 per cent) and leiomyosarcoma (39, 7·0 per cent). Local recurrence-free survival (LRFS) did not differ significantly between histological subtypes (P = 0·222). Distant metastasis-free survival (DMFS) and disease-specific survival (DSS) were found to differ significantly between subtypes (P < 0·001 for both DMFS and DSS), with the worst outcomes in patients with undifferentiated pleomorphic sarcoma (5-year survival rate: 56·8 (95 per cent c.i. 52·5 to 61·1) per cent for DMFS; 60·1 (55·6 to 64·6) per cent for DSS). However, on multivariable analysis, histological subtype was not found to be independently prognostic for LRFS, DMFS or DSS. Metastatic disease developed in 149 patients, with the lungs being the most common site of first metastasis (120 patients, 80·5 per cent). The site of first metastasis differed between subtypes, with extrapulmonary metastases predominant in myxoid liposarcoma (11 of 13 patients; P < 0·001). CONCLUSION: Although histological subtype was not found to be an independent prognostic factor for oncological outcomes, the site of first metastasis differed significantly between subtypes.

Isolated Limb Perfusion with Melphalan and Tumour Necrosis Factor α for In-Transit Melanoma and Soft Tissue Sarcoma.

BACKGROUND: Isolated limb perfusion (ILP) is indicated in locally advanced melanoma and soft tissue sarcoma of the extremities. This series reports the outcome of patients undergoing ILP with melphalan and tumour necrosis factor α (TNFα) at a single centre. METHODS: All patients undergoing ILP from January 2005 to January 2015 were identified from a prospectively maintained database. Those undergoing ILP for in-transit melanoma (ITM) were grouped according to disease burden: low volume and bulky (>2 cm diameter). RESULTS: A total of 143 perfusions were attempted: 9 and 134 in the upper and lower limbs, respectively. A response was assessable in 129 patients with overall response rates for ITM and sarcoma of 81.8 and 61.1 %, respectively. No difference was found in response rates between low-volume and bulky ITM. Limb salvage rates in these cohorts were 97 and 62 %. Regional toxicity following ILP was minimal with 7 grade III (5.4 %), and 1 grade V (0.8 %) reactions. Median progression-free survival was 11 months in the ITM cohort and 12 months in the sarcoma cohort. In the ITM cohort, complete responses were significantly more durable than partial responses (p = 0.0004). Median disease-specific survival was 21 months in the ITM cohort and was not reached in the sarcoma cohort. CONCLUSIONS: TNFα-based ILP is safe and provides excellent palliation of ITM due to rapid progression of systemic disease. It is less effective in sarcoma due to lower initial response rates and a lower incidence of disease dissemination.

Percutaneous core needle biopsy in retroperitoneal sarcomas does not influence local recurrence or overall survival.

BACKGROUND: Tumours within the retroperitoneum can cause a diagnostic dilemma. A preoperative core needle biopsy often is required to establish a histological diagnosis. Preoperative core needle biopsy for extremity soft-tissue sarcoma is oncologically safe and biopsy site recurrence is extremely rare, attributed to placing the biopsy site within the planned resection field. This study investigates whether preoperative core needle biopsy affects oncological outcomes in retroperitoneal sarcomas. METHODS: Patients undergoing resection of intermediate- and high-grade primary retroperitoneal sarcoma from 1990 until 2011 were included. Primary endpoints were immediate biopsy-related complications, local recurrence, and overall survival. RESULTS: A total of 150 patients were included in the analysis. Of these, 90 patients underwent resection after a preoperative biopsy. Median follow-up was 48 months. One patient required hospital admission postbiopsy for an abdominal wall rectus sheath haematoma. No patient developed intra-abdominal complications that required hospitalisation or early operation related to core needle biopsy. No patient developed a biopsy site recurrence. There was no significant increase in either local recurrence (p = 0.101) or overall survival (p = 0.191) after core needle biopsy. CONCLUSIONS: Preoperative core needle biopsy for retroperitoneal sarcomas is safe and does not affect oncological outcome.

Outcome following resection of retroperitoneal sarcoma.

BACKGROUND: Retroperitoneal sarcoma comprises a range of different histological subtypes with dissimilar behaviour and biology. This study sought to characterize the morbidity and mortality associated with multivisceral resection and oncological outcomes according to subtype. METHODS: All patients undergoing resection of primary retroperitoneal sarcoma at the Royal Marsden Hospital between January 2005 and December 2014 were identified from a database. RESULTS: Some 362 patients underwent resection, with 292 requiring multivisceral resection. The 30-day mortality rate was 1·4 per cent (5 patients), the 30-day morbidity rate was 15·7 per cent (57 patients), and 27 patients required a return to theatre. Age over 75 years was predictive of 30-day mortality (hazard ratio 1·37, 95 per cent c.i. 1·13 to 1·65). The overall disease-specific survival rate at 3 years was 81·2 per cent. For well differentiated liposarcoma, dedifferentiated liposarcoma and leiomyosarcoma, 3-year local recurrence-free survival rates were 98 (95 per cent c.i. 83 to 99), 56·7 (45·7 to 66·2) and 80 (67 to 89) per cent respectively. At 3 years the distant metastasis-free survival rate was 100, 85·9 (77·4 to 91·4) and 65 (49 to 77) per cent, and the disease-specific survival rate was 97 (89 to 99), 78·5 (74·6 to 82·4) and 79 (63 to 85) per cent for well differentiated liposarcoma, dedifferentiated liposarcoma and leiomyosarcoma respectively. CONCLUSION: Resection of retroperitoneal sarcoma was associated with a 30-day mortality rate of less than 2 per cent and a morbidity rate of 15·7 per cent. The overall 3-year disease-specific survival rate was 81·2 per cent.

Surgical treatment of gastrointestinal stromal tumour of the rectum in the era of imatinib.

BACKGROUND: Gastrointestinal stromal tumours (GISTs) of the rectum often require radical surgery to achieve complete resection. This study investigated the management and outcome of surgery for rectal GISTs and the role of imatinib. METHODS: A cohort study was undertaken of patients identified from a database at one tertiary sarcoma referral centre over a continuous period, from January 2001 to January 2013. RESULTS: Over 12 years, 19 patients presented with a primary rectal GIST. Median age was 57 (range 30-77) years. Neoadjuvant imatinib was used in 15 patients, significantly reducing mean tumour size from 7·6 (95 per cent c.i. 6·1 to 9·0) to 4·1 (2·8 to 5·3) cm (P < 0·001). Nine of these patients underwent surgical resection. Imatinib therapy enabled sphincter-preserving surgery to be undertaken in seven patients who would otherwise have required abdominoperineal resection or pelvic exenteration for tumour clearance. Neoadjuvant imatinib treatment also led to a significant reduction in mean(s.d.) tumour mitotic count from 16(16) to 4(9) per 50 high-power fields (P = 0·015). Imatinib was used only as adjuvant treatment in two patients. There were three deaths, all from unrelated causes. Eleven of the 13 patients who underwent resection were alive without evidence of recurrence at latest follow-up, with a median disease-free survival of 38 (range 20-129) months and overall survival of 62 (39-162) months. CONCLUSION: The use of neoadjuvant imatinib for rectal GISTs significantly decreased both tumour size and mitotic activity, which permitted less radical sphincter-preserving surgery.

Desmoid-type fibromatosis.

Desmoid-type fibromatosis is a rare, locally infiltrative, mesenchymal neoplasm that is associated with high rates of local recurrence but lacks the potential to metastasise. The disease affects younger individuals, with a peak age of 30 years, and is the most common cause of an anterior abdominal wall mass in young women of childbearing age. It may, however, involve nearly every body part, including the extremities, head and neck, trunk, and abdominal cavity; as such, desmoid-type fibromatosis may present to a range of general and subspecialty radiologists. These rare tumours have a widely variable clinical presentation and unpredictable natural history, hence input from a soft-tissue tumour centre is recommended, although much of the imaging may be performed at the patient's local hospital. The consensus for treatment has changed over the past decade, with most centres moving away from primary radical surgery towards a front-line 'watch-and-wait' policy. Therefore, imaging has an increasingly important role to play in both the diagnosis and follow-up of these patients. This review will discuss the typical imaging characteristics of these lesions and suggest diagnostic and follow-up magnetic resonance imaging protocols, with details of suitable sequences and scanning intervals.

Outcomes of routine ilioinguinal lymph node dissection for palpable inguinal melanoma nodal metastasis.

BACKGROUND: Patients who present with palpable inguinal melanoma nodal metastasis have two surgical options: inguinal or ilioinguinal lymph node dissection. Indications for either operation remain controversial. This study examined survival and recurrence outcomes following ilioinguinal dissection for patients with palpable inguinal nodal metastasis, and assessed the incidence and preoperative predictors of pelvic nodal metastasis. METHODS: This was a retrospective clinicopathological analysis of consecutive surgical patients with stage III malignant melanoma. All patients underwent a standardized ilioinguinal dissection at a specialist tertiary oncology hospital over a 12-year period (1998-2010). RESULTS: Some 38.9 per cent of 113 patients had metastatic pelvic nodes. Over a median follow-up of 31 months, the 5-year overall survival rate was 28 per cent for patients with metastatic inguinal and pelvic nodes, and 51 per cent for those with inguinal nodal metastasis only (P = 0.002). The nodal basin control rate was 88.5 per cent. Despite no evidence of pelvic node involvement on preoperative computed tomography (CT), six patients (5.3 per cent) with a single metastatic inguinal lymph node had metastatic pelvic lymph nodes. Logistic regression analysis showed that the number of metastatic inguinal nodes (odds ratio 1.56; P = 0.021) and suspicious CT findings (odds ratio 9.89; P = 0.001) were both significantly associated with metastatic pelvic nodes. The specificity of CT was good (89.2 per cent) in detecting metastatic pelvic nodes, but the sensitivity was limited (57.9 per cent). CONCLUSION: Metastatic pelvic nodes are common when palpable metastatic inguinal nodes are present. Long-term survival can be achieved following their resection by ilioinguinal dissection. As metastatic pelvic nodes cannot be diagnosed reliably by preoperative CT, patients presenting with palpable inguinal nodal metastasis should be considered for ilioinguinal dissection.

Soft-tissue masses in the abdominal wall.

Masses involving the abdominal wall arise from a large number of aetiologies. This article will describe a diagnostic approach, imaging features of the most common causes of abdominal wall masses, and highly specific characteristics of less common diseases. A diagnostic algorithm for abdominal wall masses combines clinical history and imaging appearances to classify lesions.

Unplanned excision of soft tissue sarcoma results in increased rates of local recurrence despite full further oncological treatment.

BACKGROUND: Unplanned excision of soft tissue sarcoma (STS) accounts for up to 40% of all initial operations for STS and is undertaken when the mass is presumed to be benign. The effect this has on outcome has never been fully established. METHODS: Patients with extremity or trunk STS between 2001 and 2005 who were treated by an initial inadvertent operation and then referred immediately to our unit were identified. Outcomes were compared with a control group of patients with STS who were stage-matched and had been treated conventionally by core biopsy and definitive surgery. Endpoints were local recurrence, distant metastases and sarcoma-specific survival. RESULTS: 134 patients who had undergone unplanned excision of STS were identified. One hundred twenty-one underwent further re-excision, and 51 (48%) of these patients had residual tumour identified after surgical re-excision. Two hundred nine stage-matched controls were identified who were treated conventionally. Median follow-up was 51.6 months. Local recurrence rates were considerably higher in the study group (23.8 vs. 11%, p = 0.0016), despite the control group having more stage 3 tumours. When the tumours were matched by stage, an increase in local recurrence was seen across all stages but was most pronounced for stage 3 tumours (37.5 vs. 14.2%, p = 0.005). Metastasis-free and sarcoma-specific survival were also significantly increased for stage 3 tumours. CONCLUSION: Unplanned initial excision of extremity soft tissue sarcoma may compromise long-term local control of extremity STS despite full further oncological management.

Surgical resection for non-familial adenomatous polyposis-related intra-abdominal fibromatosis.

BACKGROUND: Intra-abdominal fibromatosis (IAF) in the context of familial adenomatosis polyposis (FAP) is associated with significant morbidity and high recurrence rates after surgical resection. Non-surgical treatments are therefore advocated. This study explored outcomes in patients with IAF not associated with FAP who underwent surgical resection. METHODS: Data were analysed from a prospectively collected database at a sarcoma tertiary referral centre. RESULTS: From 2001 to 2011, 15 patients without FAP underwent primary curative surgical resection of IAF. Their median (range) age was 42 (19-64) years. Median tumour size was 18 (8.5-25) cm and weight 1306 (236-2228) g. Complete macroscopic clearance was obtained in all patients. There were no deaths in hospital or within 30 days and only one patient developed a major complication. Median follow-up was 40 (6-119) months. During follow-up two patients developed a recurrence after a disease-free interval of 12 and 16 months. CONCLUSION: In contrast to FAP-associated IAF, non-FAP-associated IAF has a very low recurrence rate after surgical resection. Surgical resection is therefore advocated as first-line treatment in patients with non-FAP-associated IAF when resection can be performed with low morbidity.

Monoclonal antibody capture and viral clearance by cation exchange chromatography.

Traditionally, post-production culture harvest capture of therapeutic monoclonal antibodies (mAbs) is performed using Protein A chromatography. We investigated the efficiency and robustness of cation exchange chromatography (CEX) in an effort to evaluate alternative capture methodologies. Up to five commercially available CEX resins were systematically evaluated using an experimentally optimized buffer platform and a design-of-experiment (DoE) approach for their ability to (a) capture a model mAb with a neutral isoelectric point, (b) clear three model viruses (porcine parvovirus, CHO type-C particles, and a bacteriophage). This approach identified a narrow operating space where yield, purity, and viral clearance were optimal under a CEX capture platform, and revealed trends between viral clearance of PPV and product purity (but not yield). Our results suggest that after unit operation optimization, CEX can serve as a suitable capture step.

Approach to screening for Familial Adenomatous Polyposis (FAP) in a cohort of 226 patients with Desmoid-type Fibromatosis (DF): experience of a specialist center in the UK.

INTRODUCTION: Desmoid-type fibromatosis (DF) are locally infiltrative, non-metastasizing tumours associated with significant morbidity and mortality if located intra-abdominally, retroperitoneally or in head and neck localisation. They are mostly sporadic, due to somatic CTNNB1 mutations. Alternatively, they can be associated with germline pathogenic variants in APC causing Familial Adenomatous Polyposis (FAP). Germline APC variants and somatic CTNNB1 mutations are mutually exclusive. AIMS AND METHODS: We conducted a retrospective descriptive analysis of patients with DF seen at the Royal Marsden NHS Foundation Trust Sarcoma Unit in London. We aimed to describe the methods of screening for FAP in patients with DF from a specialist unit. Patients diagnosed between 1992 and 2020 were selected from the prospectively maintained Sarcoma Unit database. RESULTS: 226 patients were identified and 67% (n = 152) were female. Median age at diagnosis was 37.5 (range 2-81) years. Tumour localisation was limbs/pelvis in 30.9% (N = 70), intra-abdominal 16.8% (N = 38), abdominal wall 23.5% (N = 53), thorax 18.6% (N = 42), head and neck 3.1% (N = 7) and vertebral/paravertebral 7.1% (N = 16). Colonoscopy was requested in 65 patients (28.8% of all cases) and was completed in forty-six (20.4%). Molecular testing of CTNNB1 testing was requested in 35 cases (15.5%). APC germline test was requested in 12 cases. Four patients in our cohort had an FAP-associated DF. CONCLUSIONS: CTNNB1 ± APC testing and colonoscopy are useful tools for the screening of patients with DF. CTNNB1 molecular testing should be performed in all cases of newly diagnosed DF. Negative CTNNB1 results, alongside clinical assessment, should prompt APC testing and/or colonoscopy.

CT diagnosis of ilioinguinal lymph node metastases in melanoma using radiological characteristics beyond size and asymmetry.

BACKGROUND: Diagnosis of lymph node (LN) metastasis in melanoma with non-invasive methods is challenging. The aim of this study was to evaluate the diagnostic accuracy of six LN characteristics on CT in detecting melanoma-positive ilioinguinal LN metastases, and to determine whether inguinal LN characteristics can predict pelvic LN involvement. METHODS: This was a single-centre retrospective study of patients with melanoma LN metastases at a tertiary cancer centre between 2008 and 2016. Patients who had preoperative contrast-enhanced CT assessment and ilioinguinal LN dissection were included. CT scans containing significant artefacts obscuring the pelvis were excluded. CT scans were reanalysed for six LN characteristics (extracapsular spread (ECS), minimum axis (MA), absence of fatty hilum (FH), asymmetrical cortical nodule (CAN), abnormal contrast enhancement (ACE) and rounded morphology (RM)) and compared with postoperative histopathological findings. RESULTS: A total of 90 patients were included. Median age was 58 (range 23-85) years. Eighty-eight patients (98 per cent) had pathology-positive inguinal disease and, of these, 45 (51 per cent) had concurrent pelvic disease. The most common CT characteristics found in pathology-positive inguinal LNs were MA greater than 10 mm (97 per cent), ACE (80 per cent), ECS (38 per cent) and absence of RM (38 per cent). In multivariable analysis, inguinal LN characteristics on CT indicative of pelvic disease were RM (odds ratio (OR) 3.3, 95 per cent c.i. 1.2 to 8.7) and ECS (OR 4.2, 1.6 to 11.3). Cloquet's node is known to be a poor predictor of pelvic spread. Pelvic LN disease was present in 50 per cent patients, but only 7 per cent had a pathology-positive Cloquet's node. CONCLUSION: Additional CT radiological characteristics, especially ECS and RM, may improve diagnostic accuracy and aid clinical decisions regarding the need for inguinal or ilioinguinal dissection.

Adequate surgical margins for dermatofibrosarcoma protuberans - A multi-centre analysis.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive tumour. Adequate margins have a positive impact on recurrence rates. The aim of this study is to assess how adequate margins are achieved and secondly which additional treatment modalities might be necessary to achieve adequate margins. MATERIAL & METHODS: Patients with DFSP treated between 1991 and 2016 at three tertiary centres were included. Patient- and tumour characteristics were obtained from a prospectively held database and patient files. RESULTS: A total of 279 patients with a median age of 39 (Interquartile range [IQ], 31-50) years and a median follow-up of 50 (IQ, 18-96) months were included. When DFSP was preoperatively confirmed by biopsy and resected with an oncological operation in a tertiary centre, in 86% was had clear pathological margins after one excision. Wider resection margins were significantly correlated with more reconstructions (p = 0.002). A substantial discrepancy between the primary surgical macroscopic and the pathological margins was found with a median difference of 22 (range, 10-46) mm (Fig. 1). There was no significant influence of the width of the pathological clear margins (if > 1 mm) and the recurrence rate (p = 0.710). CONCLUSION: The wider the resection margins, the more likely it is to obtain clear pathological margins, but the more likely patients will need any form of reconstruction after resection. The aim of the primary excision should be wide surgical resection, where the width of the margin should be balanced against the need for reconstructions and surgical morbidity.