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.

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.

Epithelioid hemangioendothelioma, an ultra-rare cancer: a consensus paper from the community of experts.

Epithelioid hemangioendothelioma (EHE) is an ultra-rare, translocated, vascular sarcoma. EHE clinical behavior is variable, ranging from that of a low-grade malignancy to that of a high-grade sarcoma and it is marked by a high propensity for systemic involvement. No active systemic agents are currently approved specifically for EHE, which is typically refractory to the antitumor drugs used in sarcomas. The degree of uncertainty in selecting the most appropriate therapy for EHE patients and the lack of guidelines on the clinical management of the disease make the adoption of new treatments inconsistent across the world, resulting in suboptimal outcomes for many EHE patients. To address the shortcoming, a global consensus meeting was organized in December 2020 under the umbrella of the European Society for Medical Oncology (ESMO) involving >80 experts from several disciplines from Europe, North America and Asia, together with a patient representative from the EHE Group, a global, disease-specific patient advocacy group, and Sarcoma Patient EuroNet (SPAEN). The meeting was aimed at defining, by consensus, evidence-based best practices for the optimal approach to primary and metastatic EHE. The consensus achieved during that meeting is the subject of the present publication.

Whole-body MRI: a practical guide for imaging patients with malignant bone disease.

Whole-body magnetic resonance imaging (MRI) is now a crucial tool for the assessment of the extent of systemic malignant bone disease and response to treatment, and forms part of national and international recommendations for imaging patients with myeloma or metastatic prostate cancer. Recent developments in scanners have enabled acquisition of good-quality whole-body MRI data within 45 minutes on modern MRI systems from all main manufacturers. This provides complimentary morphological and functional whole-body imaging; however, lack of prior experience and acquisition times required can act as a barrier to adoption in busy radiology departments. This article aims to tackle the former by reviewing the indications and providing guidance for technical delivery and clinical interpretation of whole-body MRI for patients with malignant bone disease.

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.

Embryonal and Alveolar Rhabdomyosarcoma in Adults: Real-Life Data From a Tertiary Sarcoma Centre.

AIMS: Embryonal and alveolar rhabdomyosarcoma (ERMS, ARMS) are subtypes of RMS that mainly occur in children, with relatively good outcomes. The incidence in adults is extremely low and survival is significantly worse compared with children. Data are scarce and literature generally combines all RMS subtypes, including pleomorphic RMS, which primarily occurs in adults and behaves more like undifferentiated pleomorphic sarcoma. The aim of this study was to evaluate patient and tumour characteristics, outcome and prognostic factors in adult patients with ERMS and ARMS. MATERIALS AND METHODS: All adult (18 years or older) ERMS and ARMS patients (presenting 1990-2016) were identified from a prospectively maintained database and were included in this analysis. RESULTS: Overall, 66 patients were included (42 men, 24 women). The median age at presentation was 28 years (range 18-71). The median overall survival for all ARMS (n = 42) and ERMS (n = 24) patients was 18 months, with a 5-year overall survival rate of 27%. Patients presenting with localised disease (n = 38, 58%) and metastatic disease (n = 25, 42%), had a 5-year overall survival rate of 36% and 11%, respectively. In univariate analysis we found alveolar subtype, fusion gene positivity, infiltrative tumour and metastatic presentation to be negative prognostic factors. CONCLUSION: Survival in adult ERMS and ARMS patients is poor and the current data may be useful in the design of trials with novel agents. Ideally, paediatric and adult oncologists should set up trials together to get a better understanding of biological, genetic and clinically relevant factors in this disease.

CT imaging improves histopathological grading of retroperitoneal leiomyosarcomas.

BACKGROUND: Initial grading of retroperitoneal leiomyosarcoma (LMS) is performed by core biopsy (CB) however, discrepancy between grade of tumour at initial CB and surgical excision is recognised, raising concerns about the accuracy of CB for directing neoadjuvant therapy. The histological grading system used for staging LMS consists of 3 components: tumour differentiation, mitotic index and proportion of necrosis. We postulate that assessment of necrosis by histopathology alone is inadequate, resulting in under-grading of LMS. We propose and assess a combined grading system that incorporates CT scan findings into pre-surgical grading. METHODS: Retrospective, blinded review of CT, CB histology and final surgical histology of patients with retroperitoneal LMS was undertaken. A modified grading system, CTH-Grade, was derived by replacing the CB necrosis score with a CT-derived necrosis score. The sensitivity and specificity of CTH-Grade, the standard histopathology scoring, H-grade were compared. Inter-observer variability in assessment of CT necrosis was also assessed. RESULTS: 53 patients fulfilled criteria for inclusion. CT was more sensitive at detection of necrosis than CB histology alone with sensitivity of 100% vs 53%. The use of CTHGrade resulted in increased detection of high-grade tumours with CTH-grade having sensitivities of 80% and 35% for Grade 2 and 3 tumours respectively vs 53% and 15% with H-Grade. Assessment of reader agreement demonstrated Kappa scores of 0.8. CONCLUSION: Histology from CB under-grades LMS due to undersampling of tumour necrosis. CT is more sensitive in assessing necrosis and its incorporation into a modified CT-histopathology grading system (CTH-Grade) improves accuracy of grading with significant implications for patient management.

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.

Aggressive fibromatosis response to tamoxifen: lack of correlation between MRI and symptomatic response.

BACKGROUND: One of the commonly used systemic agents for the treatment of aggressive fibromatosis is the anti-oestrogen drug tamoxifen. However, data on efficacy and optimum methods of response assessment are limited, consisting mainly of small case series and reports. METHODS: A retrospective database was used to identify consecutive patients diagnosed with aggressive fibromatosis (AF) and treated with tamoxifen plus/minus non-steroidal anti-inflammatory drugs at our tertiary referral centre between 2007 and 2014. MRI and symptom changes were recorded. RESULTS: Thirty-two patients (13 male 19 female, median age 41 years) were included. Median duration of treatment with tamoxifen was 316 days. Of 9 patients with progressive disease by RECIST 1.1 (28%): 4 patients experienced worsening symptoms; 3 patients had improved symptoms and 2 had no change in symptoms. Of 22 patients with stable disease (69%): 11 had no change in symptoms; 6 had improved symptoms and 5 patients had worsening symptoms. One patient achieved a partial response with improved symptoms. CONCLUSIONS: No relationship was identified between symptomatic benefit and response by RECIST 1.1 on MRI. Prospective studies in AF should incorporate endpoints focusing on patient symptoms.

An update on the management of sporadic desmoid-type fibromatosis: a European Consensus Initiative between Sarcoma PAtients EuroNet (SPAEN) and European Organization for Research and Treatment of Cancer (EORTC)/Soft Tissue and Bone Sarcoma Group (STBSG).

Desmoid-type fibromatosis is a rare and locally aggressive monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Currently, there is no established or evidence-based treatment approach available for this disease. Therefore, in 2015 the European Desmoid Working Group published a position paper giving recommendations on the treatment of this intriguing disease. Here, we present an update of this consensus approach based on professionals' AND patients' expertise following a round table meeting bringing together sarcoma experts from the European Organization for Research and Treatment of Cancer/Soft Tissue and Bone Sarcoma Group with patients and patient advocates from Sarcoma PAtients EuroNet. In this paper, we focus on new findings regarding the prognostic value of mutational analysis in desmoid-type fibromatosis patients and new systemic treatment options.

The management of soft tissue tumours of the abdominal wall.

BACKGROUND: Soft tissue tumours of the abdominal wall account for approximately 10% of all soft tissue tumours. Tumours at this site comprise a heterogeneous group of pathologies with distinct clinical behaviours and responses to treatment. The management of these tumours has largely been extrapolated from studies of soft tissue tumours at other sites. This review aims to summarise the existing data relating to abdominal wall tumours and suggest principles for managing soft tissue tumours at this site. METHODS: Relevant articles were retrieved from a comprehensive literature search using the PubMed database. Key words included abdominal wall, soft tissue tumours, surgery, radiotherapy and chemotherapy. No restrictions on publication date were used. RESULTS: The most common pathologies presenting in the abdominal wall are desmoid tumours, soft-tissue sarcoma and dermatofibrosarcoma protuberans (DFSP). Desmoid tumours should be managed with an initial period of observation, with surgery reserved for progressive lesions. Surgery should be the primary treatment for soft-tissue sarcomas and DFSP, with radiotherapy reserved for large-high grade tumours and preferentially given pre-operatively. CONCLUSIONS: Abdominal wall tumours are rare and should be managed in centres with experience in the management of soft tissue tumours. Management should be tailored to the biological behaviour of specific pathologies.

Primary retroperitoneal soft tissue sarcoma: Imaging appearances, pitfalls and diagnostic algorithm.

Although retroperitoneal sarcomas are rare tumours, they can be encountered by a wide variety of clinicians as they can be incidental findings on imaging or present with non specific symptoms and signs. Surgical resection can offer hope of cure and patient outcomes are improved when patients are managed in high-volume specialist centers. Failure to recognize retroperitoneal sarcomas on imaging can lead to inappropriate management in inexperienced centers. Therefore it is critical that a diagnosis of retroperitoneal sarcoma should be considered in the differential diagnosis of a retroperitoneal mass with prompt referral to a soft tissue sarcoma unit. In particular, the most common retroperitoneal sarcoma subtypes, liposarcoma and leiomyosarcoma, have characteristic imaging appearances which are discussed. This review therefore aims to set the context and guide clinicians through a diagnostic pathway for retroperitoneal masses in adults which arise extrinsic to the solid abdominal viscera.

Validating a robust double-quantum-filtered (1) H MRS lactate measurement method in high-grade brain tumours.

(1) H MRS measurements of lactate are often confounded by overlapping lipid signals. Double-quantum (DQ) filtering eliminates lipid signals and permits single-shot measurements, which avoid subtraction artefacts in moving tissues. This study evaluated a single-voxel-localized DQ filtering method qualitatively and quantitatively for measuring lactate concentrations in the presence of lipid, using high-grade brain tumours in which the results could be compared with standard acquisition as a reference. Paired standard acquisition and DQ-filtered (1) H MR spectra were acquired at 3T from patients receiving treatment for glioblastoma, using fLASER (localization by adiabatic selective refocusing using frequency offset corrected inversion pulses) single-voxel localization. Data were acquired from 2 × 2 × 2 cm(3) voxels, with a repetition time of 1 s and 128 averages (standard acquisition) or 256 averages (DQ-filtered acquisition), requiring 2.15 and 4.3 min respectively. Of 37 evaluated data pairs, 20 cases (54%) had measureable lactate (fitted Cramér-Rao lower bounds ≤ 20%) in either the DQ-filtered or the standard acquisition spectra. The measured DQ-filtered lactate signal was consistently downfield of lipid (1.33 ± 0.03 ppm vs 1.22 ± 0.08 ppm; p = 0.002), showing that it was not caused by lipid breakthrough, and that it matched the lactate signal seen in standard measurements (1.36 ± 0.02 ppm). In the absence of lipid, similar lactate concentrations were measured by the two methods (mean ratio DQ filtered/standard acquisition = 1.10 ± 0.21). In 7/20 cases with measurable lactate, signal was not measureable in the standard acquisition owing to lipid overlap but was quantified in the DQ-filtered acquisition. Conversely, lactate was undetected in seven DQ-filtered acquisitions but visible using the standard acquisition. In conclusion, the DQ filtering method has proven robust in eliminating lipid and permits uncontaminated measurement of lactate. This is important validation prior to use in tissues outside the brain, which contain large amounts of lipid and which are often susceptible to motion.

Elastofibroma dorsi: The clunking tumour that need not cause alarm.

INTRODUCTION: Elastofibromas are rare, pseudo-tumours arising at the inferior pole of the scapula that have a characteristic presentation. Due to their tissue of origin and size, they may often be mistaken for soft tissue sarcomas. We present the management of patients diagnosed with elastofibroma at a single institution. METHODS: Patients diagnosed with elastofibroma between January 1995 and January 2015 were identified from a prospectively maintained histopathology database. Electronic patient records, imaging and pathology reports were retrieved and reviewed. RESULTS: Thirty seven patients were identified, with a median age of 66 years and a male-to-female ratio of 1:1.6. All tumours occurred in the characteristic subscapular location. The median maximum tumour diameter was 8.2 cm. A synchronous contralateral lesion (15.8%) was found in six patients. Cross-sectional imaging was performed in 29 patients, with magnetic resonance imaging the most common modality (59.5%). Diagnosis was confirmed with percutaneous biopsy in all but one patient, who proceeded directly to surgery. Eighteen patients were managed non-operatively; 19 opted for surgical excision due to significant symptoms. Excision was performed in a marginal fashion and, at a median follow-up of 5 months, no functional impairment or local recurrences were observed. CONCLUSIONS: Soft tissue masses greater than 5 cm in diameter should prompt the clinician to exclude soft tissue sarcoma. The diagnosis of elastofibroma may be alluded to by its typical presentation and can be confirmed by percutaneous biopsy. After excluding malignancy, these lesions can be safely managed non-operatively, with surgery reserved for symptomatic patients.

Evaluation of response after pre-operative radiotherapy in soft tissue sarcomas; the European Organisation for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) and Imaging Group recommendations for radiological examination and reporting with an emphasis on magnetic resonance imaging.

At present, there is no standardised approach for the radiological evaluation of soft tissue sarcomas following radiotherapy (RT). This manuscript, produced by a European Organisation for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) and Imaging Group endorsed task force, aims to propose standardisation of magnetic resonance imaging techniques and interpretation after neoadjuvant RT for routine use and within clinical trials.

Evaluation of response after neoadjuvant treatment in soft tissue sarcomas; the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) recommendations for pathological examination and reporting.

At present, there is not a commonly used and generally accepted standardized approach for the pathologic evaluation of pretreated soft tissue sarcomas. Also, it is still unclear whether the cut-off for prognostic relevance is similar in the many different histological subtypes of STS. This manuscript, produced by a European Organization for Research and Treatment of Cancer - Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) endorsed task force, aims to propose standardization of the pathological examination process and the reporting of STS resection specimens after neoadjuvant radio- and/or chemotherapy.

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.

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.