Solitary fibrous tumours of the pleura: do we need a different perspective on malignancy?

OBJECTIVES: Solitary fibrous tumours of the pleura (SFTP) are historically considered to be benign soft tissue neoplasms. However, a clinical relevant number of these neoplasms have malignant histological features. The objective of this study was to evaluate the percentage of SFTP presenting unfavourable clinical behaviour in order to predict negative long-term outcome. METHODS: A retrospective review of 74 patients treated at 4 hospitals between 1990 and 2013 was performed. The median follow-up was 10 years (range: 1-20 years). Risk of tumour recurrence and metastases (unfavourable clinical behaviour) with regard to histology using the Kaplan-Meier and Cox proportional hazards methods. RESULTS: The mean age was 61 years (SD 12.75 years). There were 31 male patients (58%) and 43 female patients (42%). Tumour size ranged from 1 to 30 cm (mean 9.09 cm; SD 6.22 cm). Complete resection (R0) was achieved by minimally invasive thoracoscopic resection in 29% and thoracotomy in 57%; 25% of SFTPs showed histological evidence of malignancy, according to England criteria. Recurrence occurred in 21% and 10% of patients had metastases; 83% of patients with metastases and 39% of patients with recurrence died within 5 years. The median recurrence-free survival for histologically benign SFTP was not reached, compared to 8 years for malignant SFTP. The five-year overall survival rate was 84%. Mitotic rate ≥1/10 HPF, high cellularity, nuclear atypia, Ki-67 level >5% and poorly circumscribed (sessile) growth pattern were associated with poor long-term outcome. CONCLUSIONS: Pathological differentiation of SFTP morphology into pedunculated, well circumscribed and poorly circumscribed (sessile) growth pattern is recommended. Due to the misleading classification into histologically benign and malignant, all unpedunculated SFTP should be classified as potentially aggressive. Lifelong follow-up is mandatory.

Giant cell-rich solitary fibrous tumour of the urinary bladder: case report of an unusual histological variant and literature review.

BACKGROUND: Giant cell-rich solitary fibrous tumour (GCR-SFT), previously referred to as giant cell angiofibroma, is an uncommon soft tissue tumour that classically occurs in the orbit but very rarely presents in deep organs. Here, we present a case of GCR-SFT occurring in the urinary bladder, which is one of the unusual histological subtypes of SFT. CASE PRESENTATION: A 56-year-old man was incidentally found to have a mass measuring 4.5 × 4.3 × 4.0 cm located in the left posterior wall of the bladder by computed tomography during a physical examination. The lesion was confirmed as GCR-SFT by pathological examination after laparoscopic radical surgery. Histopathologically, the tumour was a well-circumscribed, nonencapsulated lesion that was composed of bland spindle-ovoid tumour cells alternating with hypocellular and hypercellular areas, staghorn-like vasculatures and scattered large dark-stained multinucleate giant cells lining pseudovascular spaces. The spindle-ovoid cells and multinucleate giant cells showed strong and diffuse expression of CD34 and nuclear STAT6. In addition, the hallmark of the NAB2ex4-STAT6ex5 fusion gene was detected by RT‒PCR. The patient was classified as having a low risk of recurrence or metastasis according to the risk stratification criteria. The patient underwent regular follow-up for 34 months after surgery, and there was no evidence of local recurrence or metastasis. CONCLUSION: This is the first reported case of GCR-SFT occurring in the urinary bladder with underlying NAB2ex4-STAT6ex5 fusion. Complete surgical excision of the tumour and long-term follow-up are recommended to ensure no local recurrence or metastasis.

Surgical Treatment of the Solitary Fibrous Tumour/ Haemangiopericytoma of the External Auditory Canal: A Case Report.

A solitary fibrous tumour (SFT)/haemangiopericytoma (HPC) accounts for approximately 1% of all vascular tumours, and 13-25% of them are present in the head and neck region. Here, a case of SFT in the left EAC has been reported with the longest duration follow-up among the previously reported cases.

Solitary fibrous tumours involving the genitourinary tract: a case series in rare locations, highlighting the role of STAT6 immunohistochemistry.

Solitary fibrous tumour (SFT) is a mesenchymal neoplasm with variable behaviour, very rarely involving the genitourinary (GU) tract. Most reported cases correspond to isolated case reports. STAT6 immunohistochemistry is a more recent and reliable diagnostic marker. The pathology database of two tertiary institutes was searched for SFTs involving the GU tract. STAT6 strong diffuse nuclear staining confirmed the diagnosis in all four cases, and the NAB2::STAT6 fusion was demonstrated by NGS in one case. Two cases were diagnosed in needle biopsy, one involving the prostate and the other involving the seminal vesicle. One case corresponded to a pelvic mass inseparable from and infiltrating the prostate and bladder. The remainder represented an exceedingly rare involvement of the spermatic cord. Involvement by a SFT should be considered in the differential diagnosis of spindle cell lesions involving GU organs. STAT6 strong diffuse nuclear staining is an important ancillary tool, particularly in a biopsy.

Regorafenib in advanced solitary fibrous tumour: Results from an exploratory phase II clinical study.

BACKGROUND: To investigate the activity of regorafenib in advanced solitary fibrous tumour (SFT). METHODS: An Italian monocentric investigator-initiated exploratory single-arm Phase II trial was conducted of regorafenib in adult patients with advanced and progressive SFT, until progression or limiting toxicity. Prior treatment with antiangiogenics was allowed. Primary and secondary end-points were: overall response rate (ORR) by Choi criteria, and ORR by RECIST, progression-free survival (PFS), overall survival (OS). RESULTS: From January 2016 to February 2021, 18 patients were enroled [malignant-SFT = 13; dedifferentiated-SFT (D-SFT) = 4; typical-SFT (T-SFT) = 1]. Fourteen patients were pre-treated, in 12 cases with antiangiogenics (median [m-] lines of treatment = 3). Sixteen patients were evaluable for response (one screening failure; one early discontinuation). Six/16 (35.2%) required a definitive dose reduction. ORR by Choi was 37.5% (95% CI: 15.2-64.6), with 6/16 (37.5%) partial responses (PR), 6/16 (37.5%) stable disease (SD) and 4/16 (25%) progressions; 5/6 responses occurred in patients pre-treated with antiangiogenics. No responses were detected in D-SFT. Best RECIST responses were: 1/16 (6.2%) PR, 12/16 (75%) SD, 3/16 (18.8%) progressions. At 48.4 month m-FU, m-PFS by Choi was 4.7 (inter-quartile range: 2.4-13.1) months, with 31.2% patients progression-free at 1 year. CONCLUSION: Regorafenib showed activity in SFT, with 30% patients free-from-progression at one year. Responses were observed also in patients pretreated and refractory to another antiangiogenic agents. However, ORR and m-PFS were lower than reported with other antiangiogenics, and this was possibly due to discrepancies in the patient population and the high-rate of dose reductions.

Primary retroperitoneal solitary fibrous tumor: A case report.

Primary retroperitoneal masses have numerous differential diagnoses, many of which are rare entities. These can be neoplastic or nonneoplastic. Among the rare conditions are solitary fibrous tumors, which can either be benign or malignant. It is a mesenchymal, spindle-cell tumor, reported first in 1931 as a pleural tumor by Klemperer et al. A 20-year-old lady, with abdominal pain for 6 months, was diagnosed with a retroperitoneal mass on the left lower abdomen on USG which was confirmed by an MRI scan of the abdomen. The patient underwent laparoscopy-assisted excision of the mass. The final histopathological reports and immunohistochemistry reports revealed a solitary fibrous tumor. Solitary fibrous tumors (SFTs) are rare tumors in the retroperitoneum. In our search, fewer than a hundred cases have been reported. It has a characteristic "patternless pattern" in a microscopic study. Adverse outcomes of SFTs are associated with atypical features in histology, such as nuclear pleomorphism, necrosis, increased cellularity, and mitoses >4/10 HPF and size more than 10 cm. The standard of care is surgical excision with clear margins. Open surgeries have been done traditionally; we present a case where we performed the excision laparoscopically.

Pleural-based giant solitary fibrous tumour with associated hypoglycaemia: unusual presentation with pulmonary hypertension in a patient with Doege-Potter syndrome.

Refractory hypoglycaemia in a patient with a solitary fibrous tumour (SFT) is very rare and was first reported in 1930 independently by Doege and Potter, leading to it being named 'Doege-Potter syndrome'. Here, we report the unusual case of a 77-year-old woman with a giant solitary fibrous pleural tumour who presented with complicating pulmonary hypertension and associated heart failure with hypoglycaemia, and subsequently underwent curative resection of the pleural mass with clinical improvement.

Solitary fibrous tumour of the urinary bladder - A rare and potentially malignant neoplasm.

Solitary fibrous tumours (SFTs) of the urinary bladder are a rare mesenchymal neoplasm that occasionally has malignant potential. The tumour is characterised by haphazardly arranged spindle-shaped to ovoid cells, with a prominent, branching, thin-walled, dilated vasculature and NAB2-STAT6 gene rearrangement. While most SFTs are indolent in nature, difficulty arises predicting which SFTs are potentially malignant. There are now validated risk stratification tools to help identify which SFTs are likely to metastasize and help clinicians determine management. The mainstay of treatment for SFTs remains surgery, with emerging evidence in the combined use of surgery and radiotherapy.

A multicentre retrospective study on extra-thoracic solitary fibrous tumour: preoperative MRI findings predict intraoperative findings and postoperative prognosis.

OBJECTIVE: The present study investigated the relationships between the preoperative and operative findings of solitary fibrous tumour (SFT) and between preoperative findings and prognosis. METHODS: We reviewed 50 SFT patients treated at our musculoskeletal oncology hospital group. We analyzed preoperative clinical findings, particularly MRI imaging findings, and intraoperative information as well as the relationship between preoperative findings and outcomes. RESULTS: Mean age was 48.9 years and the mean follow-up was 51.8 months. Prior to surgery, needle biopsy was performed on 27 patients and open biopsy on 14. T2-weighted images showed a high signal intensity in 24 patients and heterogeneous signal intensity in 20. Tumours had polylobular contours in 17 patients and smooth and round contours in 27. Collateral feeding vessels were detected in 22 patients. Gd-enhanced MRI was performed on 23 patients, and showed 15 with homogeneous enhancement and 8 with heterogeneous enhancement. Surgical times were significantly longer in patients with a retroperitoneal origin, a tumour of 10 cm or more, and polylobular-type tumours. Intraoperative blood loss was significantly greater in patients with a retroperitoneal origin and heterogeneous Gd-MRI-enhanced tumours. In histopathological evaluations, surgical margins were positive in 12 patients. Local recurrence was observed in one patient. Distant metastasis was noted in eight patients, four of whom had pulmonary metastases. Positive surgical margins were more common in polylobular-type tumours. Distant metastases were more likely to appear in patients with observable collateral feeding vessels and heterogeneous Gd-MRI enhancement. CONCLUSION: The present results suggest that preoperative clinical findings in SFT patients predict longer surgical times and the risk of increased intraoperative blood loss. Moreover, the risk of a positive surgical margin and postoperative distant metastases may be predicted based on preoperative MRI.

Solitary Fibrous Tumour: A Rare Differential Diagnosis of Unilateral Nasal Mass.

Solitary fibrous tumors of the nasal cavity and paranasal sinuses are rarely encountered in clinical practice. These are unusual mesenchymal tumours initially described as primary spindle-cell neoplasms. Such tumours may manifest in pleural and extrapleural sites such as the liver, parapharyngeal space, sublingual and parotid glands, and thyroid but are seldom described in the nose and paranasal sinus region. Erosion of adjacent structures may occur, but the tumour itself does not metastasise. A young patient presented with a progressive unilateral nasal mass. The initial nasal biopsy reported it as a benign inflammatory nasal polyp. Imaging revealed a large, locally expansile mass within the right nasal cavity displacing the nasal septum. The patient underwent excision of the tumour and the diagnosis of solitary fibrous tumour was confirmed by immunohistochemistry staining. This case is intended to highlight the diagnosis and management of this rare tumour.

Solitary fibrous tumour of the gallbladder: A rare case report.

INTRODUCTION AND IMPORTANCE: Solitary fibrous tumours are rare mesenchymal neoplasms with limited malignant potential that can occur anywhere in the body, with a predilection towards body cavities such as the pleura. It has been reported to arise in the peritoneum and the mesentery. CASE PRESENTATION: This is a case of a female patient who presented with an incidental abdominal mass compressing the duodenum. Differential diagnosis included GIST and intra-operatively was found to be arising from the gallbladder. En-bloc cholecystectomy was done and diagnosed a solitary fibrous tumour. CLINICAL DISCUSSION: This is the second case of gallbladder solitary fibrous tumour reported in the literature. CONCLUSION: Awareness of this rare entity is important for diagnosis and treatment.

Intracranial Solitary Fibrous Tumour Management: A French Multicentre Retrospective Study.

BACKGROUND: Intracranial solitary fibrous tumour (iSFT) is an exceptional mesenchymal tumour with high recurrence rates. We aimed to analyse the clinical outcomes of newly diagnosed and recurrent iSFTs. METHODS: We carried out a French retrospective multicentre (n = 16) study of histologically proven iSFT cases. Univariate and multivariate Cox models were used to estimate the prognosis value of the age, location, size, WHO grade, and surgical extent on overall survival (OS), progression-free survival (PFS), and local recurrence-free survival (LRFS). RESULTS: Eighty-eight patients were included with a median age of 54.5 years. New iSFT cases were treated with gross tumour resection (GTR) (n = 75) or subtotal resection (STR) (n = 9) and postoperative radiotherapy (PORT) (n = 32, 57%). The median follow-up time was 7 years. The median OS, PFS, and LRFS were 13 years, 7 years, and 7 years, respectively. Forty-two patients experienced recurrence. Extracranial metastasis occurred in 16 patients. Median OS and PFS after the first recurrence were 6 years and 15.4 months, respectively. A higher histological grade was a prognosis factor for PFS (p = 0.04) and LRFS (p = 0.03). GTR influenced LRFS (p = 0.03). CONCLUSION: GTR provided benefits as a first treatment for iSFTs. However, approximately 40% of patients experienced relapse, which remains a challenging state.

Orbital solitary fibrous tumours: clinicopathological characteristics and recurrence prediction.

BACKGROUND: SFTs are thought to have an unpredictable clinical course and currently have no recognized prognostic criterion. Our study aimed to determine the relationship between clinicopathological characteristics and the prognosis of patients with orbital SFTs. METHODS: The clinicopathological features of these patients were extracted from clinical records. The relationships between these features and prognosis were analysed. RESULTS: The positive rates of CD34, CD99, Blc2, and STAT6 expression were 90.3%, 90.3%, 83.9%, and 100%, respectively. The tumour recurrence rate was 38.7%. A higher recurrence rate was observed in patients with Ki67 index ≥ 5 (56.25% vs. 20%, P = 0.038). CONCLUSION: A Ki67 index ≥ 5 was an effective parameter for predicting tumour recurrence of orbital SFTs. Close follow-up is needed for these patients.

Recurrent meningeal malignant tumor: Assessment of differences in the solitary fibrous tumor/hemangiopericytoma spectrum through a case report / Tumor maligno recurrente de origen meníngeo: evaluación de las diferencias de la entidad tumor fibroso solitario/hemangiopericitoma mediante un caso clínico

Solitary fibrous tumors (SFTs) are neoplasms that grow from mesenchymal fusiform cells. In the central nervous system, meninges are the common origin of these neoplasms. Although literature reports mostly SFT as benign neoplasm, malignancy data have been described in recurrences or metastatic lesions. Definitive diagnosis includes immunohistochemical profiles assessing cellular positivity for CD34, vimentin, CD99 and Bcl-2. Recent studies have demonstrated NAB2-STAT6 gene fusion as a distinct molecular feature of SFT with overexpression of the fusion protein NAB2-STAT6 in nuclei of these cells. Since several years, pathologists have grouped SFT and hemangiopericytomas (HPC) as different phenotypes of the same entity although both neoplasms do not share numerous features. This article, based on a case of a recurrent malignant SFT, aims to emphasize differences in the SFT/HPC spectrum due to the diagnostic, therapeutic and prognostic implications (AU)

Los tumores fibrosos solitarios (TFS) son neoplasias que crecen a partir de células mesenquimales y las meninges constituyen su origen preferente en el sistema nervioso central. Aunque la literatura relaciona la mayoría de los TFS como neoplasias benignas, se describen datos de malignidad en recidivas tumorales o lesiones metastásicas. El diagnóstico definitivo incluye el perfil inmunohistoquímico, que evalúa la positividad celular para CD34, vimentina, CD99 y Bcl-2. Estudios recientes han demostrado la fusión del gen NAB2-STAT6 como una característica molecular distintiva de los TFS, con sobreexpresión de la proteína de fusión NAB2-STAT6 en los núcleos de las células. Los patólogos han agrupado los TFS y los hemangiopericitomas como diferentes fenotipos de una misma entidad, aunque ambas neoplasias no comparten numerosas características. Este artículo, basado en un caso de una lesión maligna recurrente, tiene como objetivo enfatizar las diferencias en el espectro SFT/hemangiopericitoma por sus implicaciones diagnósticas, terapéuticas y pronósticas (AU)

Multidisciplinary treatment of giant presacral solitary fibrous tumour: a case report and literature review.

Solitary fibrous tumours (SFTs) usually occur at the pleura. Extrapleural sites, particularly giant extrapleural solitary fibromas, are more rarely observed in the clinic, and the clinical diagnosis and treatment of this disease is a focus of attention. Herein, the case of a 43-year-old male patient with giant presacral SFT successfully treated by open surgery, and with a final diagnosis confirmed by postoperative pathology and immunohistochemistry, is reported. The patient was followed-up regularly during 5 years after surgery, with no obvious surgical complications, and no tumour recurrence noted on pelvic magnetic resonance imaging. This case provides clinical information that may help in the diagnosis and treatment of complex SFT.

Recurrent meningeal malignant tumor: Assessment of differences in the solitary fibrous tumor/hemangiopericytoma spectrum through a case report.

Solitary fibrous tumors (SFTs) are neoplasms that grow from mesenchymal fusiform cells. In the central nervous system, meninges are the common origin of these neoplasms. Although literature reports mostly SFT as benign neoplasm, malignancy data have been described in recurrences or metastatic lesions. Definitive diagnosis includes immunohistochemical profiles assessing cellular positivity for CD34, vimentin, CD99 and Bcl-2. Recent studies have demonstrated NAB2-STAT6 gene fusion as a distinct molecular feature of SFT with overexpression of the fusion protein NAB2-STAT6 in nuclei of these cells. Since several years, pathologists have grouped SFT and hemangiopericytomas (HPC) as different phenotypes of the same entity although both neoplasms do not share numerous features. This article, based on a case of a recurrent malignant SFT, aims to emphasize differences in the SFT/HPC spectrum due to the diagnostic, therapeutic and prognostic implications.

Peripheral Inflammatory Indexes Neutrophil/Lymphocyte Ratio (NLR) and Red Cell Distribution Width (RDW) as Prognostic Biomarkers in Advanced Solitary Fibrous Tumour (SFT) Treated with Pazopanib.

Pazopanib was assessed prospectively in the GEIS-32 phase II study (NCT02066285) on advanced solitary fibrous tumour (SFT), resulting in a longer progression-free survival (PFS) and overall survival (OS) compared with historical controls treated with chemotherapy. A retrospective analysis of peripheral inflammatory indexes in patients enrolled into GEIS-32 was performed to evaluate their prognostic and predictive value. Patients received pazopanib 800 mg/day as the first antiangiogenic line. The impacts of baseline neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and red cell distribution width (RDW) on PFS, OS, and Choi response were evaluated by univariate and multivariate analysis. Metastasis-free interval (MFI), mitotic count, and ECOG were also included as potential prognostic factors. Sixty-seven SFT patients, enrolled in this study, showed a median age of 63 years and a female/male distribution of 57/43. The median follow-up from treatment initiation was 16.8 months. High baseline NLR, PLR, and standardised RDW were significantly associated with worse PFS and OS. NLR, RDW, MFI, and mitotic count were independent variables for PFS, while RDW and ECOG were independent for OS. Further, NLR and mitotic count were independent factors for Choi response. High baseline NLR and RDW values were independent prognostic biomarkers for worse outcome in advanced SFT patients treated with pazopanib.

ISG15 as a prognostic biomarker in solitary fibrous tumour.

BACKGROUND: Solitary fibrous tumour (SFT) is a rare mesenchymal malignancy that lacks robust prognostic and predictive biomarkers. Interferon-stimulated gene 15 (ISG15) is a ubiquitin-like modifier, associated with tumour progression, and with poor survival of SFT patients, as previous published by our group. Here, we describe the role of ISG15 in the biology of this rare tumour. METHODS: ISG15 expression was assessed by immunohistochemistry in tissue microarrays from SFT patients and tested for correlation with progression-free survival and overall survival (OS). The effects of ISG15 knockdown or induction were investigated for cancer stem cell (CSC) characteristics and for drug sensitivity in unique in vitro models of SFT. RESULTS: The prognostic value of ISG15 for OS was validated at protein level in malignant SFT patients, prospectively treated with pazopanib and enrolled in GEIS-32 trial. In SFT in vitro models, ISG15 knockdown lead to a decrease in the expression of CSC-related genes, including SOX2, NANOG, ALDH1A1, ABCB1 and ABCC1. Likewise, ISG15 downregulation decreased the clonogenic/ tumoursphere-forming ability of SFT cells, while enhancing apoptotic cell death after doxorubicin, pazopanib or trabectedin treatment in 3D cell cultures. The regulation of CSC-related genes by ISG15 was confirmed after inducing its expression with interferon-ß1; ISG15 induction upregulated 1.28- to 451-fold the expression of CSC-associated genes. CONCLUSIONS: ISG15 is a prognostic factor in malignant SFT, regulating the expression of CSC-related genes and CSCs maintenance. Our results suggest that ISG15 could be a novel therapeutic target in SFT, which could improve the efficacy of the currently available treatments.

Cytomorphological spectrum of solitary fibrous tumour: revisited.

BACKGROUND: Solitary fibrous tumour (SFT) is a tumour of mesenchymal origin. Its diagnosis on cytology is challenging, owing to variation in cellularity, sparsely distributed cellular and stromal components. Cytomorphological findings for this type of tumour have rarely been described in the literature-only a few case reports and the occasional case series have been presented thus far. We present the cytomorphological features of SFT with special emphasis on immunochemical findings. MATERIALS AND METHODS: We present cytological data from eight cases of histopathologically proven SFTs. The cytomorphological features, immunochemical markers and differential diagnostic entities on fine needle aspiration cytology are discussed. RESULTS: Fine needle aspiration was performed at various anatomical sites. Cytology smears showed variable cellularity, with tumour cells arranged in loose clusters and as singly scattered cells. Interlacing fascicles with palisading of cells was noted. The cells were predominantly spindle to elongated, having moderate cytoplasm with elongated wavy nuclei. These nuclei had fine to coarse chromatin, with inconspicuous to prominent nucleoli. There was prominent, metachromatically staining, amorphous to fibrillary, collagenous to myxoid matrix material associated with the tumour cells. Other findings included intranuclear pseudo-inclusions, multinucleated giant cells and atypical mitoses. Cytological diagnoses offered varied from 'spindle cell neoplasm' to 'spindle cell sarcoma' or 'suggestive of sarcoma'. Immunocytochemistry (ICC) performed on cell block sections showed positivity for STAT6, CD34 and Bcl-2. CONCLUSION: Cytological diagnosis of SFT can be challenging. A careful search for characteristic cytomorphological features is diagnostically helpful. The cytomorphology should be interpreted with caution, with an appropriate ICC panel, including STAT6 and CD34.

Identifying the uncommon solitary fibrous tumour in a rare location - A case report.

INTRODUCTION AND IMPORTANCE: The authors describe a case work up of an unusual natal cleft soft tissue tumour which eventually was concluded as solitary fibrous tumour. Solitary fibrous tumour is an uncommon fibroblastic tumour which commonly presents in pleural region and very rarely in extrapleural location such as natal cleft. Accurate identification of this tumour, considering the indeterminate nature of the tumour irrespective of the location, avoided misdiagnosis and played a vital role in follow up management of the patient. CASE PRESENTATION: 43 year old female patient presented with a painless lump in the natal cleft region for a short duration of 7 months with no other significant medical or surgical or family or psychosocial history. She was not on any regular medications. CLINICAL DISCUSSION: Due to unusual location of the tumour broad range of differential diagnosis including benign and malignant entities were discussed based on histological findings and immunophenotyping. Mammary type myofibroblastoma, glomus tumour, clear cell renal cell carcinoma and clear cell sarcoma of soft tissue were few to note. STAT6 immunohistochemical stain played a crucial role in unravelling this case. Due to gradual increase in size of the lump complete surgical excision was performed with no local recurrence of the tumour. CONCLUSION: It is important to recognise this rare mesenchymal tumour with intermediate malignant potential occurring at uncommon natal cleft region for which complete surgical enucleation is curative.