Solitary fibrous tumor of the thyroid gland: report of seven cases.

Solitary fibrous tumor is a soft tissue neoplasm initially described in the pleura but subsequently reported in a wide variety of locations. The clinical behavior is usually benign, but the existence of aggressive cases has been documented both in the pleura and in extrapleural sites. In this report clinical and pathologic features of seven solitary fibrous tumors of the thyroid gland are presented. Patients' ages ranged from 43 to 64 years (mean 52 years), and tumor sizes varied from 2 to 6 cm. Grossly, the tumors were white-tan and well circumscribed. Microscopically, there was a variegated, wavy, storiform, hemangiopericytic or desmoid-like arrangement of spindle cells. Trapped thyroid follicles within the tumor and peripheral jagged tumor infiltration among follicles were common. There was immunohistochemical reactivity for CD34, CD99, and bcl-2, and ultrastructural analysis of one tumor was consistent with a fibroblastic lineage. The differential diagnosis included other benign and malignant mesenchymal tumors of the thyroid, spindle cell follicular adenoma, Riedel's thyroiditis, the spindle cell, and paucicellular variants of anaplastic carcinoma, papillary thyroid carcinoma with exuberant nodular fasciitis-like stroma, and the spindle epithelial tumor with thymus-like differentiation. The cumulative data of 13 cases (comprised of the seven present cases and the six previously reported) suggest a benign clinical behavior for thyroid SFT.     

Solitary fibrous tumors of the pleura: clinicopathological and immunohistochemical examination

The purpose of this work was to study clinical and biological characteristics of solitary fibrous tumor (SFT) of the pleura. We reviewed the clinicopathological and immunohistochemical features of 12 patients who underwent surgical resection for SFT. Ten cases were histologically defined as benign; two were found to be malignant. CD34 negativity and strong expression of p53 could be observed in a patient with fatal outcome. Ki-67 expression was increased in malignant cases, as compared with benign. We also found that Bcl-2 expression inversely correlated with a tumor diameter. As the development of malignant SFT might be associated with these molecular statuses, immunohistochemical staining should be performed in all cases to identify the biological characteristics of the tumor.     

Malignant solitary fibrous tumor of the nasal cavity.

Solitary fibrous tumors (SFTs) are unusual mesenchymal tumors that were first described as primary spindle-cell neoplasms of the pleura. These tumors have been described in many other locations, including the urogenital system, orbit, mediastinum, and upper respiratory tract. Twenty-two cases of an SFT of the paranasal sinuses and nasal cavity have been reported, but none described a malignant SFT extending through the anterior skull base. A 70-year-old man had a 6-month history of unilateral left-sided epiphora and nasal obstruction. Computed tomography and magnetic resonance imaging showed a large left-sided nasal cavity mass with extension into the left extraconal orbit and intracranial extension through the left cribriform plate and ethmoid roof. The patient underwent preoperative embolization of the internal maxillary artery and a subsequent anterior craniofacial resection via a midfacial degloving approach and a left anterior craniotomy. Histopathological analysis of the specimen was consistent with a malignant SFT.     

An Aggressive Solitary Fibrous Tumor with Evidence of Malignancy: A Rare Case Report

Solitary fibrous tumor (SFT) is rare mesenchymal neoplasm that has been originally and most often documented in the pleura. Recently, the ubiquitous nature of the SFT has been recognized with reports of involvement of numerous sites all over the body, i.e, upper respiratory tract, breast, somatic tissue, mediastinum, head, and neck, etc. The diagnosis of SFT still remains an enigma in our field. Furthermore, malignant SFT is extremely rare and only two cases have been reported in the oral cavity till date. Here, we present a rare case report of an aggressive solitary fibrous tumor which presented as a palatal mass and extended throughout the middle cranial fossa and exhibited features of malignancy.     

Solitary fibrous tumors arising in abdominal wall hernia sacs.

Solitary fibrous tumor (SFT) of the peritoneum is an unusual spindle-cell neoplasm. SFT was originally described in the pleura; however it is now diagnosed in multiple extrathoracic sites. Most believe that the tumor is of mesenchymal origin and should be classified as a variant of fibroma. SFT of the pleura and peritoneum have also been called fibrous mesothelioma, and the cell of origin is felt to be a pluripotential submesothelial mesenchymal cell. Primary tumors arising in hernia sacs are rare, and we report on two patients with hernia SFT. The first is a 67-year-old man who had a diffusely thickened distal left inguinal hernia sac. Within the sac was copious myxoid material mimicking pseudomyxoma peritonei. Herniorrhaphy and orchiectomy were performed. The second is a 44-year-old woman with a midepigastric mass attached to a ventral hernia. Wide local excision was performed. Both tumors demonstrated plump spindle cells, one with myxoid background and the other with keloidal collagen. Calretinin immunostaining was positive in both tumors, whereas CD34 was negative. This suggests tumor origin from a submesothial pluripotential cell that maintains potential for mesothelial differentiation. Surgical excision is the treatment of choice with the degree of resectability being a powerful predictor of outcome.     

Solitary fibrous tumor of the orbit. Case report and review of the literature.

BACKGROUND: Solitary fibrous tumor (SFT), which usually presents in the pleura and is thought to be mesothelial in nature, has been recently discovered in extrapleural sites, including the orbit. Presently ultrastructural studies show absence of epithelial-mesothelial features, and reactivity of the tumor cells to CD34 antigen on immunohistochemical analysis suggests the mesenchymal origin of such tumors. CASE DESCRIPTION: A 40-year-old woman had a 4-year history of progressive swelling of her right upper lid and a slow-growing palpable mass of the orbit. CT and MR imaging showed a well circumscribed, nonenhanced extraconal mass with mild erosion of the right orbital roof. The tumor was totally excised. Histological examination disclosed a spindle-cell tumor in a dense fibrous tissue. Immunohistochemistry showed positive staining for vimentin and CD34. We review the clinical, diagnostic, and surgical features of 22 orbital SFTs including the present case. CONCLUSIONS: Orbital SFT generally pursues a slow, indolent, and nonaggressive course, reaches a size up to 4.5 cm, and can be cured by a single excision. It must be immunohistochemically differentiated from other spindle-cell tumors of the orbit.     

Solitary fibrous tumor of the pleura presenting as an aneurysm-like lesion with the strongly contrasted tumor stain by angiography

We treated a patient with solitary fibrous tumor of the pleura (SFT) whose angiograms demonstrated its feeders and strongly contrasted tumor stain. Although no one has clearly identified the specific features of SFT on angiograms, SFT can be suspected in the clinical setting if a localized chest wall tumor presents with the feeders and strongly contrasted tumor stain shown by angiography.     

The solitary fibrous malignant tumour of the kidney: clinical and pathological considerations on a case revisiting the literature

The solitary fibrous tumours (SFT) are rare spindle cell neoplasms which generally originate from the pleura; also described are cases of SFT in other locations, included the genital-urinary tract. Described in the ambit the kidney are 19 cases of SFT and such rarity of localisation makes rather unknown the histogenesis and the prognosis of the lesion. We report the case of a 72 year old lady who attended our Unit for a mass which was clinically palpable at the level of the left hemiabdomen. Following an abdominal ultrasound scan a neoformation was highlighted which a successive tomodensitographic test indicated as being of likely pertinence of the middle third of the left kidney; the mass had a diameter of approximately 19 cm. A radical nephrectomy has been conducted. The histological examen highlighted a solitary fibrous tumour: the presence of hypercellularity, of cellular pleiomorphism and of a high number of mitosis has led to a histopathological diagnosis of malignancy of the neoplasm under examination. Departing from this case a review of the literature is carried out. The SFT of the kidney can have an aggressive character and more the present has hystopathological characters and clinical results are still rather unknown.     

Primary solitary fibrous tumor (SFT) in the retroperitoneum

BACKGROUND: Solitary fibrous tumor (SFT) is an infrequent but distinct neoplasm, which generally arises from submesothelial connective tissue in the pleura. SFT is rarely recognized in extrathoracic sites, and histologically identical conditions have also been reported in the retroperitoneum, although their pathophysiology has not been extensively investigated. METHODS: We present four cases of primary SFT in the retroperitoneum, and review 37 similar cases in the previous literature. RESULTS: About 40% of patients were asymptomatic, and 19.2% and 15.4% presented with an abdominal mass and urinary symptoms, respectively. The tumor size ranged between 2 and 26 (mean 9.1) cm. Sixty-three percent of tumors showed nonspecific development with haphazard distribution of bland short spindle or polygonal cells with or without collagenous bundles and stromal hyalinization. In 22.0%, hemangiopericytomatous appearance was seen. About 15% of cases showed histologically malignant characteristics. The tumor cells were immunoreactive for vimentin in all cases, CD34 in 91% and Bcl-2 in 86%. All tumors were excised, and in 85.4% of cases, tumors did not recur postoperatively for 6 to 48 months. No significant difference was found between the recurrence rate of histologically benign and malignant cases. Cases positive for both CD34 and Bcl-2 had no recurrence. CONCLUSIONS: The identification of SFT in the retroperitoneum is of importance because histopathological indicators of malignancy are not necessarily associated with clinical malignant potential in many cases of retroperitoneal SFT. Retroperitoneal SFT showing typical pathological features with expression of CD34 and Bcl-2 is associated with a favorable outcome following excision.     

Solitary fibrous tumor of the pancreas: Case report and review of the literature

Solitary fibrous tumor (SFT) is a mesenchymal tumor typically located in the pleura, but can also be found as an asymptomatic mass in other areas, including the liver, peritoneum, kidney and salivary glands. However, SFT rarely locates in the pancreas. We present such a case of pancreatic SFT, along with a review of all reported cases. A 55-year-old man was treated surgically for an asymptomatic pancreatic mass after a rigorous preoperative control. Histologic examination of the resected specimen showed characteristics of an SFT. As only 15 cases of pancreatic SFT have been reported so far, an attempt to compare the cases was considered intriguing. We found that patients with pancreatic SFT were mainly women (81.25%), with a median age of 54 years at the time of diagnosis and a median tumor size of 5.83 cm. Pancreatic SFTs were revealed incidentally in 50% of cases, and all of them showed an enhancement through arterial computed tomography. All tumors were positive for CD34, ten were positive for Bcl-2, and twelve were negative for S100. The diagnosis of this pancreatic tumor is established by a combination of clinical suspicion, imaging procedures and histological findings, and is confirmed by immunohistochemical staining. Although the behavior of SFTs is rather benign, close clinical follow-up is recommended due to a potentially malignant nature.     

Solitary fibrous tumor of the peritoneum found in the prevesical space

Solitary fibrous tumors (SFT) are well recognized in the pleura, but their rare occurrence at other sites has become appreciated only in recent years. We experienced a 68-year-old male patient who presented with frequency of urination and difficulty in voiding. Computed tomographic scan revealed a solid and cystic mass which measured 12 x 10 cm in the prevesical space. This tumor showed typical histopathologic features of SFT, and was immunostained positive for vimentin, CD34 and CD99. This is an extremely rare case of SFT arising from the parietal peritoneum found in the prevesical space.     

Solitary fibrous tumor of the meninges: two new cases and review of the literature

BACKGROUND

Solitary fibrous tumor (SFT), a mesenchymal neoplasm originally described in the pleura has been more recently reported to arise in a number of other sites, including the meninges. Nowadays immunohistochemistry facilitates the otherwise problematic differential diagnosis with regard to other benign and malignant spindle cell neoplasms of the central nervous system.

METHODS

Two recently treated cases of meningeal SFT (one craniospinal, one spinal) are presented and discussed in the light of the present knowledge and a review of the literature.

RESULTS

Total resection was followed by complete recovery and both patients are presently asymptomatic and without evidence of disease. The microscopic and immunohistochemical profiles (CD 34, vimentin positive; S-100, EMA negative) were consistent with those of previously reported cases.

CONCLUSIONS

The majority of SFTs behave in a benign fashion and do not recur unless subtotally resected. Malignant variants may account for up to 37% of SFTs in other locations but have never been reported to occur in the meninges. Meningeal SFTs are to be considered a new pathological entity. Wider use of immunohistochemical screening should enable the determination of their real incidence; larger series and longer follow-up will provide conclusions about their treatment and prognosis.     

Near-infrared fluorescence imaging of a solitary fibrous tumor of the pancreas using methylene blue

A 67-year-old female presented with unexplained abdominal pain. A contrast-enhanced computed tomography scan of the abdomen incidentally revealed a mass in the uncinate process of the pancreas. This mass was resected and based on histopathological findings, diagnosed as a solitary fibrous tumor (SFT) of the pancreas. A SFT is an extremely rare benign mesenchymal tumor that in 65% of cases affects the visceral pleura but can also affect extra-pleural sites. The intraoperative demarcation of pancreatic tumors, such as SFTs, can bechallenging. In this report, the first clear intraoperative identification of a SFT of the pancreas in a human was shown using near-infrared fluorescence and methylene blue.     

Multiple recurrent malignant solitary fibrous tumors: long-term follow-up of 24 years

Solitary fibrous tumor (SFT) of the pleura is a rare, generally benign, neoplasm that accounts for less than 5% of all pleural tumors. However, 10% to 30% of SFTs display aggressive behavior with local recurrence, malignant transformation, and distant metastasis. We report a case of multiple recurrent SFTs of the thorax in a 77-year-old Korean woman. During a 24-year period, she underwent six surgical resections for six recurrent SFTs. The tumor eventually underwent morphologically malignant transformation. This unique case highlights the necessity of long-term follow-up in cases of SFT because of the potentially malignant biological behavior of this type of tumor.     

Severe hypoglycaemia associated with a giant solitary fibrous tumor of the pleura

Solitary fibrous tumors (SFT) of the pleura are a rare neoplasm, with benign biological behaviour. Recurrences are rare, and no distant metastases are described in the literature. SFT can secrete hormone-like substances, responsible for paraneoplastic syndromes. The authors describe a case of severe hypoglycaemia due to insulin-like growth factor II (IGF-2)'s secretion by a giant SFT of the pleura. Hypoglycaemia was controlled by the resection of the tumor. Diagnosis and surgical management of these neoplasms are also discussed.     

Giant pelvic solitary fibrous tumor obstructing intestinal and urinary tract: a case report and literature review

We are reporting a giant pelvic neoplasm, a rare solitary fibrous tumor that presented with a large bowel obstruction and bilateral ureteral obstruction because of its size and location. Preoperative diagnosis required complex pathological studies to exclude a high-grade sarcoma suspected clinically. Complete resection was required for resolution of obstructive symptoms. Prognosis for solitary fibrous tumors is usually good after complete resection. Recurrence and metastasis may be related to rare aggressive histological features, including nuclear atypia, hypercellularity, greater than four mitoses/10 high power fields, and necrosis. Because histology is not always a reliable predictor of prognosis, careful long-term follow-up is necessary for this tumor. Solitary fibrous tumors (SFTs) are rare spindle cell neoplasms most likely arising from mesenchymal cells. SFTs were originally described in the pleura, the most common site for this tumor; however, extrathoracic SFTs are seemingly diagnosed with increased frequency. We report a case of a giant pelvic SFT that required complicated clinical management.     

Solitary fibrous tumor of the mediastinum. A report of 14 cases

Fourteen cases of a mediastinal neoplasm identical to solitary fibrous tumor (so-called fibrous mesothelioma) of the pleura were observed. The lesions presented with cough, chest pain, dyspnea, or as asymptomatic masses detected radiographically. Two patients had associated hypoglycemia. Eleven of the tumors were in the antero-superior mediastinum. One arose on a pedicle from the thymus, and another had entrapped thymic elements. Tumor cells were variably immunoreactive for vimentin and actin, but not for keratin, and lacked ultrastructural evidence of mesothelial or epithelial differentiation. Eight cases had highly cellular mitotically active regions of which six of seven with follow-up behaved aggressively; the exception was the pedunculated tumor. A 13-cm, histologically bland tumor has recurred twice. Aggressive behavior was more common than reported for solitary fibrous tumor of the pleura, but the same criteria (size, cellularity, mitotic activity, presence of pedicle) were of prognostic significance. The occurrence of solitary fibrous tumor in the mediastinum with the suggestion of thymic origin for some cases, combined with the immunohistochemical and ultrastructural findings, support a mesenchymal origin for this tumor. The differential diagnosis includes spindle cell thymoma, hemangiopericytoma, and peripheral nerve tumors.     

Metastatic solitary fibrous tumor of the meninges. Case report

Solitary fibrous tumor (SFT) is a unique tumor composed of interstitial dendritic cells that was first described in the thorax and subsequently reported in diverse organs. Extrathoracic SFTs are predominantly benign but rare malignant cases have been documented. In the nervous system, SFT has been described as a meningeal lesion although all 14 previously reported cases were benign. The authors report the first case of a meningeal SFT occurring in a 55-year-old woman. The tumor first presented as a meningeal lesion that after three recurrences over a 10-year period metastasized to the soft tissues and lungs. The potentially malignant nature of cranial SFTs, especially those with atypical histological features and high mitotic counts, should be recognized.     

A resected case of solitary fibrous tumor of the pleura

A 45-year-old female with solitary fibrous tumor (SFT) of the pleura was reported. Chest X-ray and CT scan on admission showed a large tumor in the right thoracic cavity. A preoperative needle biopsy was performed. The microscopic appearance of biopsied specimen revealed many spindle cells. And an immunohistochemical study was positive for CD 34 and negative for keratin, epithelial membrane antigen, alpha-smooth muscle actin, S-100 protein. So SFT was strongly suspected and an operation was performed. A tumor arised from the visceral pleura of right middle lobe and was pedunculated. The tumor was 13 x 10 x 7.5 cm in size. An immunohistochemical study of the tumor was positive for CD 34, and negative for SMA, ki-67. From these immunohistochemical stainings and microscopic findings, the tumor was diagnosed as SFT. An immunohistochemical study of the tumor seems to be very useful for the diagnosis of SFT.