Low Metastatic Potential Research Articles

Recurrent Dermatofibrosarcoma Protuberans of the Head and Neck: a Case Series.

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous sarcoma that develops from dermal fibroblasts and spreads within the dermis and subcutaneous fat. It is locally aggressive, with a high local recurrence rate after excision but has extremely low metastatic potential. In the case of recurrent tumors, surgical excision with adequate margins is the gold standard treatment and may require adjuvant radiotherapy or chemotherapy in some cases. We conducted a retrospective analysis of individuals with dermatofibrosarcoma protuberance of the head and neck region that had treatment at our facility between 2016 and 2021. We gathered the data on the surgical techniques, reconstructive techniques used, histopathological features, adjuvant therapy, and outcomes. We treated three patients with head and neck dermatofibrosarcoma protuberance: one scalp lesion and two on the cheek. All three patients had recurrent tumors, two of whom were treated elsewhere for the primary lesion. One patient underwent surgery for a benign spindle cell tumor of the right cheek, but a final histopathological examination revealed dermatofibrosarcoma protuberance, and the tumor recurred within 3months. The duration of recurrence is between 3 and 24months. The size of the tumor ranges from 7.2 to 10.5cm. The wide local excision margins range from 2 to 4cm. Reconstruction ranges from split skin graft to regional flap. Inadequate margins raise the possibility of local recurrence in dermatofibrosarcoma protuberance.

Adhesion strength and anti-tumor agents regulate vinculin of breast cancer cells.

The onset and progression of cancer are strongly associated with the dissipation of adhesion forces between cancer cells, thus facilitating their incessant attachment and detachment from the extracellular matrix (ECM) to move toward metastasis. During this process, cancer cells undergo mechanical stresses and respond to these stresses with membrane deformation while inducing protrusions to invade the surrounding tissues. Cellular response to mechanical forces is inherently related to the reorganization of the cytoskeleton, the dissipation of cell–cell junctions, and the adhesion to the surrounding ECM. Moreover, the role of focal adhesion proteins, and particularly the role of vinculin in cell attachment and detachment during migration, is critical, indicating the tight cell–ECM junctions, which favor or inhibit the metastatic cascade. The biomechanical analysis of these sequences of events may elucidate the tumor progression and the potential of cancer cells for migration and metastasis. In this work, we focused on the evaluation of the spreading rate and the estimation of the adhesion strength between breast cancer cells and ECM prior to and post-treatment with anti-tumor agents. Specifically, different tamoxifen concentrations were used for ER+ breast cancer cells, while even concentrations of trastuzumab and pertuzumab were used for HER2+ cells. Analysis of cell stiffness indicated an increased elastic Young’s modulus post-treatment in both MCF-7 and SKBR-3 cells. The results showed that the post-treatment spreading rate was significantly decreased in both types of breast cancer, suggesting a lower metastatic potential. Additionally, treated cells required greater adhesion forces to detach from the ECM, thus preventing detachment events of cancer cells from the ECM, and therefore, the probability of cell motility, migration, and metastasis was confined. Furthermore, post-detachment and post-treatment vinculin levels were increased, indicating tighter cell–ECM junctions, hence limiting the probability of cell detachment and, therefore, cell motility and migration.

EP-276 Tall Cell Carcinoma with Reverse Polarity (TCCRP) of the breast; a rare form of breast cancer

Abstract Aim A case report on the diagnosis and treatment of this rare low grade triple negative breast cancer. Case Report A 41 year old female presented with a palpable left breast lump. Family history includes a sister with a rare myeloproliferative disorder. On examination, a left breast lower outer quadrant 2–3 cm hard irregular lump was palpable. Mammography and ultrasound revealed a 25 mm suspicious lesion (which was biopsied), with normal appearing lymph nodes. Results Biopsy revealed a grade 2 invasive apocrine carcinoma. Oestrogen and Herceptin receptors negative. Breast conserving surgery with sentinel lymph node biopsy was performed. Histology revealed a 22 mm well circumscribed tumour with nests of epithelial cells in micropapillary pattern with apocrine like appearance. The most striking feature was that the nuclei were at the apical rather than the basal poles of the epithelial cells (reverse polarity). No lymphovascular invasion present. Lymph nodes were negative (0/3). Diagnosis was then confirmed by molecular testing. Conclusion Tall cell carcinoma with reverse polarity (TCCRP)1, a rare cancer resembling tall cell variant of papillary thyroid carcinoma, was first reported by Eusebi et al in 20032. Although morphologically similar to metastatic papillary thyroid cancer, neither the immunohistochemical markers nor genetic profiles have established any connection3. Accurate diagnosis of TCCRP is important as it carries an excellent prognosis. Treatment is local regional radiotherapy. There is no indication for systemic therapy in this case, due to its indolent low metastatic potential.

A Multimodal Biomarker Predicts Dissemination of Bronchial Carcinoid.

Simple SummaryEvidence of prediction of disease recurrence after curative surgery in bronchial carcinoid is still limited. The aim of this study was to retrospectively investigate a set of markers as potential predictors of dissemination. This study confirmed that adding OTP, CD44, and Ki-67 to the carcinoid classification improved the identification of patients who are at risk for metastatic disease. Patients who did not develop metastasis in follow-up had typical carcinoids with proliferation index <5% and positive OTP and CD44. Atypical carcinoids with proliferation index ≥5% and loss of OTP and/or CD44 were at high risk for distant metastases. Such patients should be screened for metastatic disease at diagnosis and during follow up.Background: Curatively treated bronchial carcinoid tumors have a relatively low metastatic potential. Gradation into typical (TC) and atypical carcinoid (AC) is limited in terms of prognostic value, resulting in yearly follow-up of all patients. We examined the additional prognostic value of novel immunohistochemical (IHC) markers to current gradation of carcinoids. Methods: A retrospective single-institution cohort study was performed on 171 patients with pathologically diagnosed bronchial carcinoid (median follow-up: 66 months). The risk of developing distant metastases based on histopathological characteristics (Ki-67, p16, Rb, OTP, CD44, and tumor diameter) was evaluated using multivariate regression analysis and the Kaplan–Meier method. Results: Of 171 patients, seven (4%) had disseminated disease at presentation, and 164 (96%) received curative-intent treatment with either endobronchial treatment (EBT) (n = 61, 36%) or surgery (n = 103, 60%). Among the 164 patients, 13 developed metastases at follow-up of 81 months (IQR 45–162). Univariate analysis showed that Ki-67, mitotic index, OTP, CD44, and tumor diameter were associated with development of distant metastases. Multivariate analysis showed that mitotic count, Ki-67, and OTP were independent risk factors for development of distant metastases. Using a 5% cutoff for Ki-67, Kaplan–Meier analysis showed that the risk of distant metastasis development was significantly associated with the number of risk predictors (AC, Ki-67 ≥ 5%, and loss of OTP or CD44) (p < 0.0001). Six out of seven patients (86%) with all three positive risk factors developed distant metastasis. Conclusions: Mitotic count, proliferation index, and OTP IHC were independent predictors of dissemination at follow-up. In addition to the widely used carcinoid classification, a comprehensive analysis of histopathological variables including Ki-67, OTP, and CD44 could assist in the determination of distant metastasis risks of bronchial carcinoids.

Dermatofibrosarcoma protuberans of the hallux: A case report with review of the literature.

Introduction and importanceDarier-Ferrand dermatofibrosarcoma (DFS) is a rare mesenchymal tumor with an aggressive local behavior, high local recurrence frequency and low metastatic potential. It commonly presents as a raised slowly growing mass. It usually occurs on trunk and proximal extremities but rarely touches distal extremities such as hands, fingers, or foot below knees.Case presentationA 15-year-old girl presents with a protuberant painful mass of the right hallux of 2 years. After surgical excision, histological examination revealed a spindle shaped cells with a strong CD34 expression and the diagnosis of Darier-Ferrand dermatofibrosarcoma of the toe was confirmed.We proceeded to a review of the literature of Dermatofibrosarcoma on the toes with the aim to reveal, its clinical presentations, histopathology, and treatment options.Clinical discussionDFS represents 0.1 % of all cancers. It is a low-grade sarcoma with a locally aggressive behavior and a low metastatic potential. Only 11 cases of DFS of the toes have been reported in the literature. It usually occurs in the trunk, and proximal extremities. Histological and immunohistochemical examination are mandatory to confirm the diagnosis with diffuse expression of CD34 by the tumoral cells. Surgery is the standard treatment for localized and resectable lesions.ConclusionDarier-Ferrand Dermatofibrosarcoma is an uncommon and recurrent dreadful tumor, that rarely occurs on toes, but should be considered in front of persistent slowly growing foot lesions.

Basal Cell Carcinoma: A Narrative Review on Contemporary Diagnosis and Management.

Basal cell carcinoma (BCC) is the most common, accounting for 80-90% of skin cancers. It arises from the basal layer of the epidermis and its appendages. A complex interplay of environmental, phenotypic and genetic variables leads to the development of BCC. Literature has documented several clinical subtypes of BCC, the most common of which are nodular, superficial and morpheaform. Expeditious diagnosis and analysis are essential for improving the outcome of BCC. Preventive measures, particularly when implemented in childhood and adolescence, may play a critical role. Due to its low metastatic potential, treatment for BCC mostly focuses on local management. The standard treatment of basal cell carcinoma involved complete removal of the lesion by excision or Mohs surgery. In special circumstances, basal cell carcinoma can be treated with cryosurgery, electrodesiccation and curettage, topical medications and photodynamic therapy. This review aimed to evaluate the contemporary diagnosis and management of basal cell carcinoma.

Active surveillance in small renal masses

Active surveillance is one of the options available for management of renal masses smaller than 4 cm with a suspicion of malignancy in association with nephrectomy and ablative procedures. In general, small renal masses grow slowly and have a very low metastatic potential, but exceptions occur. Active surveillance is generally offered in the elderly with high comorbidities but there is a lack of validated data in other patient demographics. Data from younger and healthier patients are gradually emerging and have shown promising results but still require further validation. Computed tomography (CT), magnetic resonance imagin (MRI), and ultrasonography (US) are all acceptable imaging modalities for surveillance of renal masses, but CT is the most commonly used. Intervals of surveillance differs from study to study, but the most common schedule is 3, 6, and 12 months after initiation, then annually. The cut off point for delayed intervention is growth &gt; 0.5 cm/year or absolute size &gt; 4 cm. Oncologic outcome is comparable to nephrectomy and ablation in terms of cancer-specific survival. Quality of life for patients undergoing active surveillance is also comparable but is significantly lower in those with confirmed malignant biopsy results. Cost of active surveillance is as a rule more cost effective than nephrectomy or ablation.

Active Surveillance versus Immediate Intervention for Small Renal Masses: A Cost-Effectiveness and Clinical Decision Analysis.

Active surveillance (AS) with the possibility of delayed intervention (DI) is emerging as a safe alternative to immediate intervention for many patients with small renal masses (SRMs). However, limited comparative data exist to inform the most appropriate management strategy for SRMs. Decision analytic Markov modeling was performed to estimate the health outcomes and costs of 4 management strategies for 65-year-old patients with an incidental SRM: AS (with possible DI), immediate partial nephrectomy, radical nephrectomy, and thermal ablation. Mortality, direct medical costs, quality-adjusted life-years, and incremental cost-effectiveness ratios were evaluated over 10 years. The 10-year all-cause mortality was 22.6% for AS, 21.9% for immediate partial nephrectomy, 22.4% for immediate radical nephrectomy, and 23.7% for immediate thermal ablation. At a willingness-to-pay threshold of $100,000/quality-adjusted life-year, AS was the most cost-effective management strategy. The results were robust in univariate, multivariate, and probabilistic sensitivity analyses. Clinical decision analysis demonstrated that the tumor's metastatic potential, patient age, individual preferences, and health status were important factors influencing the optimal management strategy. Notably, if the annual probability of metastatic progression from AS was sufficiently low (under 0.35%-0.45% for most ages at baseline), consistent with the typical metastatic potential of SRMs <2 cm, AS would achieve higher health utilities than the other strategies. Compared to immediate intervention, AS with timely DI offers a safe and cost-effective approach to managing patients with SRMs. For patients harboring tumors of very low metastatic potential, AS may lead to better patient outcomes than immediate intervention.

Dermatofibrosarcoma protuberans of perianal region: a rare case report

Dermatofibrosarcoma protuberans (DFSP) is a rare locally aggressive slow growing soft tissue sarcoma with very low metastatic potential with high local recurrence rates. We presented a rare case of DFSP of left perianal region ulcerating into anal canal, we did wide excision with 3 cm margin along with abdominoperineal excision of rectum and permanent colostomy, defect is reconstructed with left pedicled antero-lateral thigh flap. DFSP has high chance of recurrence, it should be excised with at least 2-3 cm 3D margin and patient should be followed up for a long time.

Electrical characterization of tumor-derived exosomes by conductive atomic force microscopy

The physical properties of tumor-derived exosomes have gained much attention because they are helpful to better understand the exosomes in biomedicine. In this study, the conductive atomic force microscopy (C-AFM) was employed to perform the electrical characterizations of exosomes, and it obtained the topography and current images of samples simultaneously. The exosomes were absorbed onto the mica substrates coated with a gold film of 20 nm thick for obtaining the current images of samples by C-AFM in air. The results showed that the single exosomes had the weak conductivity. Furthermore, the currents on exosomes were measured at different bias voltages and pH conditions. It illustrated that the conductivity of exosomes was affected by external factors such as bias voltages and solutions with different pH values. In addition, the electrical responses of low and high metastatic potential cell-derived exosomes were also compared under different voltages and pH conditions. This work is important for better understanding the physical properties of tumor-derived exosomes and promoting the clinical applications of tumor-derived exosomes.

An extrapleural solitary fibrous tumor with low metastatic potential in a young female

An extrapleural solitary fibrous tumor with low metastatic potential in a young female

Dermatofibrosarcoma Protuberans in Children.

Paediatric dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue malignant tumour which displays aggressive local behaviour and has low metastatic potential. The diagnosis is often delayed as DFSP is usually mistaken for other skin conditions, particularly in the early stages of disease. DFSP tends to follow an indolent course after the initial presentation with what is often described as a "rubbery lump". As the disease progresses, the lump tends to enlarge, change colour, and exhibit a more nodular consistency. In rare cases, DFSP can present as an ulcerated exophytic lesion or a depressed area of skin, making diagnosis even more challenging. A high index of suspicion is warranted for early diagnosis, and referral to a specialist unit with expertise in both oncologic resection and reconstruction. DFSP tumours arise from the dermis and grow with finger-like projections. Therefore, in cosmetically sensitive or functionally important locations, an excision and analysis technique that assesses all excision margins is the gold standard of care. Slow Mohs technique performed with en bloc excision is a well-tolerated option for oncologic resection of the tumour. Mohs technique can also be considered but can be challenging in children for reasons explained below. As an alternative, depending on the anatomical location, tumours can be excised with a wide local excision. While an excision technique that incorporates the deep fascia with a 3-cm peripheral margin is acceptable in adults, planning of the excision margin in children should involve consideration of preoperative imaging with MRI, site of the tumour, age, and physical built of the child. Patients should be offered all treatment options considering the local outcomes, available expertise, and cost. A multidisciplinary approach and good communication between team members is crucial. Close collaboration with a pathologist who is familiar with sectioning technique that allows margin control is of paramount importance. Soft tissue reconstruction should be performed immediately after oncologic clearance, although a staged approach may be required. Adjuvant radiotherapy should be avoided in children due to the long-term risk of secondary malignancies and potential for growth disruption.

Surgical Outcomes of Clival Chordoma Through Endoscopic Endonasal Approach: A Single-Center Experience.

ObjectiveClival chordoma is a locally aggressive tumor with low metastatic potential. In the past decade, endoscopic endonasal approach (EEA) for clival chordoma has had a higher resection rate and a lower morbidity rate than transcranial approaches. Here, we present our initial single-center experience after EEA of clival chordomas.Patients and methodsThis study retrospectively analyzed 17 consecutive patients with clival chordoma who received EEA in our department between March 2015 and September 2021. The operation was performed by a single surgeon with EEA. The clinical and pathological characteristics were analyzed along with the surgical outcomes and complications.ResultsA total of 17 consecutive patients with clival chordoma received EEA with a median follow-up of 29.2 months (range 1-79). Gross total resection (GTR) was performed in 7 cases (41%), subtotal resection (STR) in 7 case (41%) and partially resection (PR) in 3 cases (18%). Cerebrospinal fluid leakage occurred in 2 cases (12%) and meningitis developed in 3 patients (18%) which were all successfully treated with intravenous antibiotics without any complications. There were no perioperative deaths or new focal neurological deficits postoperatively. Four in 7 patients with STR have had radiotherapy while the other three chose to be monitored. Till the last follow-up, three patients in STR group who received radiotherapy (3 in 4) had no tumor regrowth, while one in STR group with radiotherapy (1 in 4) showed tumor progression. Two patients in STR group without radiotherapy (2 in 3) showed stable tumor while the left one (1 in 3) showed tumor progression. One patient in the PR group died of tumor progression 2 years postoperation and the other one showed tumor progression and died of lung cancer 1 year postoperation. In addition, 1 in 7 patients with GTR had tumor recurrence in situ after 10 months and developed surgical pathway seeding in the spinal canal in C1 after 16 months. No recurrence occurred in the other 6 cases with GTR during the follow-up.ConclusionAlthough more cases are needed, our case series showed EEA is a safe and reliable method for clival chordoma with high resection rates and low morbidity rates. GTR without tumor residuum would improve the outcome.

Integrated DNA and RNA sequencing reveals early drivers involved in metastasis of gastric cancer

Gastric cancer (GC) is the second cause of cancer-related death and metastasis is an important cause of death. Considering difficulties in searching for metastatic driver mutations, we tried a novel strategy here. We conducted an integrative genomic analysis on GC and identified early drivers lead to metastasis. Whole-exome sequencing (WES), transcriptomes sequencing and targeted-exome sequencing (TES) were performed on tumors and matched normal tissues from 432 Chinese GC patients, especially the comparative analysis between higher metastatic-potential (HMP) group with T1 stage and lymph-node metastasis, and lower metastatic-potential (LMP) group without lymph-nodes or distant metastasis. HMP group presented higher mutation load and heterogeneity, enrichment in immunosuppressive signaling, more immune cell infiltration than LMP group. An integrated mRNA-lncRNA signature based on differentially expressed genes was constructed and its prognostic value was better than traditional TNM stage. We identified 176 candidate prometastatic mutations by WES and selected 8 genes for following TES. Mutated TP53 and MADCAM1 were significantly associated with poor metastasis-free survival. We further demonstrated that mutated MADCAM1 could not only directly promote cancer cells migration, but also could trigger tumor metastasis by establishing immunosuppressive microenvironment, including promoting PD-L1-mediated immune escape and reprogramming tumor-associated macrophages by regulating CCL2 through Akt/mTOR axis. In conclusion, GCs with different metastatic-potential are distinguishable at the genetic level and we revealed a number of potential metastatic driver mutations. Driver mutations in early-onset metastatic GC could promote metastasis by establishing an immunosuppressive microenvironment. This study provided possibility for future target therapy of GC.

Validation of four cutaneous squamous cell carcinoma staging systems using nationwide data.

SummaryBackgroundCutaneous squamous cell carcinoma (cSCC) is the second most common cancer worldwide with relatively low metastatic potential (2–5%). Developments in therapeutic options have highlighted the need to better identify high‐risk patients who could benefit from closer surveillance, adjuvant therapies and baseline/follow‐up imaging, while at the same time safely omitting low‐risk patients from further follow‐up. Controversy remains regarding the predictive performance of current cSCC staging systems and which methodology to adopt.ObjectivesTo validate the performance of four cSCC staging systems [American Joint Committee on Cancer 8th edition (AJCC8), Brigham and Women’s Hospital (BWH), Tübingen and Salamanca T3 refinement] in predicting metastasis using a nationwide cohort.MethodsA nested case–control study using data from the National Disease Registration Service, England, 2013–2015 was conducted. Metastatic cSCC cases were identified using an algorithm to identify all potential cases for manual review. These were 1 : 1 matched on follow‐up time to nonmetastatic controls randomly selected from 2013. Staging systems were analysed for distinctiveness, homogeneity, monotonicity, specificity, positive predictive value (PPV), negative predictive value (NPV) and c‐index.ResultsWe included 887 metastatic cSCC cases and 887 nonmetastatic cSCC controls. The BWH system showed the highest specificity [92.8%, 95% confidence interval (CI) 90.8–94.3%, PPV (13.2%, 95% CI 10.6–16.2) and c‐index (0.84, 95% CI 0.82–0.86). The AJCC8 showed superior NPV (99.2%, 95% CI 99.2–99.3), homogeneity and monotonicity compared with the BWH and Tübingen diameter and thickness classifications (P < 0.001). Salamanca refinement did not show any improvement in AJCC8 T3 cSCC staging.ConclusionsWe validated four cSCC staging systems using the largest nationwide dataset of metastatic cSCC so far. Although the BWH system showed the highest overall discriminative ability, PPV was low for all staging systems, which shows the need for further improvement and refining of current cSCC staging systems.

Exosomal MMP-1 transfers metastasis potential in triple-negative breast cancer through PAR1-mediated EMT.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with high risk of distant metastasis, in which the intercellular communication between tumor cells also plays a role. Exosomes can be released by tumor cells and promote distant metastasis through intercellular communication or changes in tumor microenvironment, it is an optimized transportation facility for biologically active payloads. This was a hypothesis-generating research on role of exosomal payload in TNBC distant metastasis. Exosomes isolated from supernatant of MDA-MB-231 and MDA-MB-231-HM (a highly pulmonary metastatic variant of parental MDA-MB-231 cells) were characterized. MMP-1 level was detected using mass spectrometry and western blot. Transwell assay, wound healing and CCK-8 assay were employed to explore the effect of exosomal MMP-1 on the metastatic capability of TNBC cells in vitro. Human breast cancer lung metastasis model in nude mice was established to observe the effect of exosomal MMP-1 in vivo. Tissue microarray and blood samples of TNBC patients were applied to analyze the relevance between MMP-1 with metastasis. MDA-MB-231-HM cells secrete exosomes enriched MMP-1, which can be taken up and enhance invasion and migration activities of TNBC cells, including MDA-MB-231, MDA-MB-468 and BT549. After ingesting exosomes enriched with MMP-1, cells secret more MMP-1, which may interact with membrane G protein receptor protease activated receptor 1 (PAR1), thereby initiating epithelial-mesenchymal transition (EMT) to enhance capability of migration and invasion. The lung colonization model shows that the expressions of MMP-1 and PAR1 in the metastases of the 231-HM-exo treated mice were both upregulated. Clinically, the enrichment of MMP-1 can be detected in exosomes extracted from serum of patients with metastasis at higher concentration than that in pre-operative patients. Moreover, in patients with multiple distant metastases, the level of MMP-1 in exosomes is also higher than that in patients with single lesion. MMP-1 from TNBC cells of high metastasis potential can promote the distant metastasis of transform those with low metastasis potential through PAR1-mediated EMT and is likely to be a potential molecular marker.

A first stage placental site trophoblastic tumor: a case report and review of literature.

Placental site trophoblastic tumor (PSTT) is a very rare form of gestational trophoblastic disease (GTD) that occurs mainly in women who have a history of termination of pregnancy. It has different characteristics from other gestational trophoblastic tumors: it grows slowly, secretes low levels of beta-human chorionic gonadotropin (β-hCG), with low metastatic potential. We report a case of PSTT of a 32-year-old patient. Seven months after delivery, the patient presented at our Center with persistence of menorrhagia for at least 1 month. A slightly high level of beta-human chorionic gonadotropin (β-hCG) was observed. TVUS and MRI, an operative hysteroscopy and a laparoscopy were performed. The histological and immunohistochemical findings demonstrated PSTT. Diagnosis of juvenile cystic adenomyoma (JCA) was also added. A total body CT scan was negative for metastases. A total hysterectomy with salpingectomy was performed. We performed a search of relevant studies about PSTT of the last years. A systematic search of Pubmed databases was conducted. Appropriate search terms were constructed by reviewing abstracts, titles and keywords relating to PSTT known to the authors. All articles known to the authors useful to the review were included, comparing with our clinical case. Stages and treatment are related to survival rates, with long term survival expected for stage I low-risk disease after hysterectomy. Our case is a stage I disease with good prognostic factors (patient's age and absence of metastases) and, as described in the literature, a total hysterectomy with salpingectomy was performed.

A Reminder of a Rare Benign but Aggressive Tumor: Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is a slowly growing fibrous tumor of the skin with a very high risk of local recurrence, but with low metastatic potential. Its malignant sarcomatous transformation with metastasis is exceptional. We report a rare case, of a 30-year-old patient, who presents dermatofibrosarcoma protuberans in the left supraclavicular region. Through this case we will underline the clinical presentation as well as the management of this benign but aggressive tumor.

A0829 - Unexpected low metastatic potential to lymph-nodes of isolated tumor cell and cluster-cord in ISUP 5 prostate adenocarcinoma: A mono-institutional cohort analysis with clinic-pathological correlation

A0829 - Unexpected low metastatic potential to lymph-nodes of isolated tumor cell and cluster-cord in ISUP 5 prostate adenocarcinoma: A mono-institutional cohort analysis with clinic-pathological correlation

Radiofrequency ablation treatment of periacetabular chondrosarcoma: A case report

Needle biopsy of an incidental periacetabular bone lesion in an 18-year-old female showed a low-grade cartilaginous tumor. Based on the imaging and pelvic location, the tumor was considered a Grade I chondrosarcoma. Due to the young age, incidental discovery, and low metastatic potential, radiofrequency ablation (RFA) was recommended in favor over traditional wide en bloc resection. The patient has been radiographically and clinically stable for 2 years. RFA has not been previously reported for low-grade chondrosarcoma. Its use should be done only with careful consideration and diligent follow-up in this setting.