A rare case of rectal bleeding and Fusobacterium mortiferum sepsis due to solitary fibrous tumour originating from the mesentery

Solitary fibrous tumours (SFTs) are rare mesenchymal tumours that are mostly seen in the pleura. Lately, they have also been described in other locations. Recent discovery of the NAB2-STAT6 fusion gene which is specific for SFTs has led to an accurate diagnosis of SFTs. The occurrence of SFTs in the mesentery is very rarely reported in the literature. We report a case of a 63-year-old female who presented with abdominal pain, rectal bleeding and Fusobacterium bacteraemia, who was ultimately found to have a mesenteric SFT.

570 Solitary Fibrous Tumours of the Pleura: Case Series

Introduction Solitary fibrous tumours of the pleura (SFTP) are rare tumours with poorly recognised presentations and aetiology. Aim to evaluate the presentations, risk factors, investigations, management and follow up for 4 cases of SFTP Method retrospective review of medical records of 4 patients diagnosed with SFTP at the Golden Jubilee National Hospital between January-October 2020. Data was collated on presenting signs and symptoms, co-morbidities, risk factors, investigations, management and follow. A literature review was conducted, and findings discussed. Results All cases were males aged 62-85. All were referred from the same geographical area. Pre-disposing risk factors included exposure to cold-dust (1), asbestos (1) and smoking (1). Presenting symptoms were cough (3), shortness of breath (1), weight loss and fatigue (1). Associated co-morbidities were coagulopathy(2) and hyperglycaemia (1). Patients were investigated pre-operatively with chest x-ray (4), pulmonary function tests (4), PET-CT scan (4) and CT biopsy (3). One patient had genetic studies for chromosome 18 translocation. Three out of 4 patients were managed surgically with wedge resection (3) via video-assisted thoracoscopic surgery (2) or open thoracotomy(1), followed by excision biopsy studies (3). Tumours originated from the visceral (1), mediastinal (1) and parietal (1) pleura. Recurrence risk for all patients was deemed to be 20%. Follow up was with 6 monthly CT scans for 5 years (1). Conclusions SFTP is a rare tumour which presents with non-specific symptoms. Better understanding of the aetiology, presentation and investigations is needed to aid definitive diagnosis and tailored management

874 Solitary Fibrous Tumours of the Pleura: Immunohistochemistry

Aim To evaluate immunohistopathology markers of solitary fibrous tumours of the pleura (SFTP), including markers of benign and malignant variants. Method Retrospective review of immunohistopathology reports on 4 patients diagnosed with SFTP between January-October 2020 at the Golden Jubilee National Hospital. Data was collated on markers tested or detected. Benign and malignant cases were compared. A literature review was conducted to summarise the current evidence. Results Ki-67, Anti-bcl-2, CD99, STAT6, Desmin, AE1/3, Calretinin and S100 were tested in 100% (4/4) cases. CD34, EMA and CD117 were tested in 75% (3/4). Betacatenin and Vimentin were tested in 25% (1/4). Of those tested, Ki-67 was present in 100% (4/4), Anti-bcl-2 and CD99 in 75% (3/4), STAT6 in 50% (2/4), Desmin in 25% (1/4), AE1/3 in 25% (1/4), Calretinin in 25% (1/4), S100 in 0% (0/4), CD34 in 67% (2/3), EMA in 0% (0/3), CD117 in 0% (0/3), Betacatenin in 100% (1/1) and Vimentin in 100% (1/1). One out of 4 cases were malignant based on clinical presentation. Of the markers tested in all cases, Desmin was only detected in the malignant case, AE1/3 and Calretinin only in the benign cases, and the other markers in both benign and malignant cases. Anti-bcl-2 and Ki-67 intensity did not correlate with tumour diameter or malignant potential. Immunohistopathology could not confirm SFTP diagnosis in 50% (2/4) cases; it could not determine malignant potential or SFTP-subtype in 100% (4/4) cases. Conclusions A better understanding of SFTP immunohistopathology is needed for investigating SFTP, including benign and malignant tumour variants.

Solitary fibrous tumour of mediastinum: an often asymptomatic neoplasm

Solitary fibrous tumours (SFTs) are rare neoplasms derived from mesenchymal cell lines. They are often asymptomatic, follow an indolent growth pattern and are more often benign than malignant. Here, we present a case of a very large, asymptomatic mediastinal SFT in an otherwise healthy man. A 67-year-old Irish man was referred for workup of an asymptomatic murmur. Auscultation of the lung fields revealed diminished breath sounds on the right side. Chest X-ray identified a 20 cm mass localised within the thorax. CT of the thorax confirmed a pleural based, solid lesion with no local invasion. CT-guided core biopsies were reported as consistent with SFT. Primary excision of the lesion was undertaken via median sternotomy. Histological examination confirmed a diagnosis of SFT. The patient remains well at this time. Primary excisive surgery is a safe and effective treatment modality for SFTs.

Successful multidisciplinary treatment of Doege-Potter syndrome: hypoglycaemia caused by paraneoplastic IGF-2 production by a metastatic haemangiopericytoma

Hypoglycaemia due to insulin-like growth factor (IGF)-2 secretion is a paraneoplastic complication of malignancy with significant morbidity that can often go unrecognised due to its uncommon presentation. We report on a case of a 51-year-old man with metastatic haemangiopericytoma presenting with refractory hypoglycaemia, requiring continuous dextrose 10% infusion while in hospital. IGF-2 levels were significantly elevated, in keeping with a rare entity associated with solitary fibrous tumours, known as Doege-Potter syndrome. The patient was managed using uncooked cornstarch in conjunction with debulking of the hepatic tumour burden with bland IR-guided transarterial embolisation, and eventual surgical resection to treat his non-islet cell tumour hypoglycaemia (NICTH). The case highlights this rare paraneoplastic phenomenon that should be included in the differential for hypoglycaemia, especially if a history of a solitary fibrous tumour is elicited. Our case is the first to document a successful approach to treating the hypoglycaemia using preoperative transarterial bland embolisation.

An abdominal-sacral approach with preoperative embolisation for vulvar solitary fibrous tumour: a case report

Background Solitary fibrous tumours (SFTs) in the female genital tract are uncommon. Resection of these tumours is controversial because it can cause life-threatening haemorrhage. We report a case of vulvar SFT that was excised in a combined abdominal-sacral approach after preoperative embolisation. Case presentation At another hospital, an inoperable intrapelvic tumour was diagnosed in a 34-year-old woman. Computed tomography and magnetic resonance imaging showed that the uterus, urinary bladder and rectum were compressed laterally by a pelvic tumour with a maximum diameter of 11 cm. This mass was hypervascular and had a well-defined border. Transperineal biopsy was performed, and immunostaining revealed that the mass was an SFT. The tumour was supplied by feeding vessels from the right iliac arteries. First, we embolised the feeding vessels. Second, we performed surgical resection in a combined abdominal-sacral approach; no blood transfusion was necessary, and no perioperative complications occurred. The final pathological diagnosis was SFT that was positive for CD34 and signal transducer and activator of transcription 6 according to immunohistochemical staining. Conclusion During a year of follow-up, the disease did not recur. Treatment of pelvic SFT should aim at complete resection through various approaches after careful measures are taken to prevent haemorrhage.

Intrapulmonary solitary fibrous tumour: a case report

Solitary fibrous tumours (SFTs) mainly originate from the visceral pleura and may protrude to the thoracic cavity, but intrapulmonary SFTs are extremely rare. We describe a rare case of SFT arising in the right lung of an 83-year-old man who underwent surgical excision. Chest computed tomography (CT) revealed a 10-mm tumour in the lower lobe of the right lung. The size of tumour gradually increased and reached 17 mm 2 years after the first radiologic examination. Considering the possibility of malignancy, wedge resection of the right lower lobe was performed via video-assisted thoracic surgery. Microscopically, the tumour consisted mainly of spindle-shaped cells. Immunohistochemical staining indicated the tumour was positive for CD34, STAT6, vimentin and bcl-2, but negative for cytokeratins, D2–40 and S-100. Based on the histological findings, the tumour was diagnosed as SFT. The patient has been in good health for 6 months since the surgery.

Preoperative embolisation of orbital solitary fibrous tumour

Solitary fibrous tumours (SFT) is an encompassing terminology comprising of tumours with proliferating CD34 positive specialised fibroblasts. Orbital SFTs are rare slowly progressive highly vascular neoplasms. Complete surgical excision is considered the mainstay treatment. Incomplete resection is a known risk factor for recurrence and malignant transformation. Recently preoperative embolisation of SFT has shown promising results in reducing the vascularity of these tumours rendering them amenable to complete surgical excision. Less than 10 cases of embolisation of orbital solitary fibrous tumours have been described in literature. Our patient underwent an attempted surgical excision elsewhere with significant intraoperative haemorrhage which precluded its complete excision. Herein, we report successful outcome in a case of hypervascular orbital SFT managed with preoperative embolisation, surgical resection and adjuvant radiotherapy along with a review of relevant literature.

Solitary Fibrous Tumor of the Pleura: Case Report and Literature Review

Solitary fibrous tumours of the pleura (SFTPs) are rare neoplasms, usually described as relatively benign neoplasms and only 10-20% presenting malignant features. Imagistic investigations are useful in the incipient evaluation of SFTPs, and the histopathological and immunohistochemical examinations after surgical resection are mandatory for establishing the diagnosis and for differentiating SFTPs from other aetiologies of pleural masses. The unpredictable evolution (10%-20% of the cases reported in literature display malignant features) and limited data regarding the treatment needs an early detection, a complete surgical resection and long-term imagistic follow-up. We present a case of SFTPs alongside a review of the typical clinical, imagistic and pathologic features consistent with this diagnosis.