Malignant solitary fibrous tumor of the pleura

Malignant Solitary Fibrous Tumor of the Nasal Cavity and Orbit: A Case Report

Solitary fibrous tumors are well-recognized in the pleura and their occurrence in the nasal cavity is uncommon. They show a hemangiopericytoma-like vasculature, a "patternless pattern" of growth, and lesions characterized by both hypercellularity and hypocellularity. As a malignant form of SFT, mesenchymal neoplasm is extremely uncommon and poorly understood, although there are no established standards for making this diagnosis, it is nonetheless accepted. It can develop either de novo or within an already-existing benign SFT, and there are few published accounts of the cytopathologic characteristics of these tumors.In this case, a patient complained of tenderness on the right nasal root and diplopia for six months. Here, we report on a case of malignant solitary fibrous tumors in the nasal cavity, which extended into the orbit, and review the radiologic and pathologic features.

A Rare Case of a Solitary Fibrous Tumor in a Child, Presenting as a Congenital Mass, Displaying NAB2ex4::STAT6ex2 Gene Fusion with an Incidental Ganglioneuroblastoma

A solitary fibrous tumor (SFT) is a ubiquitous tumor that occurs across all ages. It is rarely reported in pediatric patients, especially as a congenital mass. A 1 year 7-month old male child presented with a slow-growing gluteal mass since birth along with a recent episode of bleeding. Magnetic resonance imaging (MRI) showed a well-defined, T1-hypointense and T2-hyperintense mass in the skin and the subcutaneous plane. Subsequently, he underwent a surgical resection that revealed a 5.7 cm-sized fleshy mass. On histopathologic examination, there was a fairly well-circumscribed, cellular spindle cell tumor, with cells arranged in intersecting fascicles and hemangiopericytomatous pattern with areas of hemorrhage and fibrinoid necrosis. Cells revealed mild nuclear atypia. Mitotic figures were up to 8/10 hpf. Immunohistochemically, the tumor cells were diffusely positive for CD34 and STAT6. Furthermore, the tumor revealed NAB2 exon 4:: STAT6 exon 2 fusion by RT-PCR and Sanger sequencing. Post-excision, during follow-up, the patient developed an adrenal mass that was histopathologically proven as a neuroblastic tumor, not further specified on biopsy and finally as ganglioneuroblastoma, intermixed type on excision. This constitutes one of the rare cases of SFT in a pediatric patient, presenting as a congenital mass, confirmed by STAT6 immunostaining and further, molecular testing. A review of literature of similar cases, including treatment-related implications, is presented.

Cervical, Intradural Extramedullary Solitary Fibrous Tumor of the Spinal Cord: A Case Report and Review of the Literature

Solitary fibrous tumors (SFTs) are rare, spindle cell neoplasms of the mesenchymal origin. Lesions localized to the spine are exceptionally uncommon, only described in the literature in case reports and small case series. While these lesions are typically benign, there are a few reports in which they recur or present as malignancies. The patient presented in the case herein was a 72-year-old male, who presented with a 1-year history of lower extremity weakness, pain, and numbness and was found to have a cervical, intradural extramedullary tumor. In addition to the case report, the authors perform a thorough review of all previously published cases of spinal SFT.

Recurrence of multiple metastases after surgical removal of a primary malignant solitary fibrous tumor from the main bronchus: A case report

RATIONALE

Limited knowledge is available regarding solitary fibrous tumors (SFTs), about 15% of which are malignant. In particular, the long-term survival of patients with malignant SFTs (mSFTs), the disease course, and the potential for recurrence of second primary tumors or distant metastases are largely undetermined.

PATIENT CONCERNS

We report a rare case in which an mSFT was found at the main bronchus of the right lung of a 37-year-old man.

DIAGNOSIS

The tumor cells of mSFT were spindle-shaped and expressed antigen Ki-67, B-cell lymphoma 2, cluster of differentiation 31, and vimentin.

INTERVENTIONS

A total pneumonectomy was performed.

OUTCOMES

The patient developed fibrosarcoma of the small intestine at 6 months, as well as extensive pleural and peritoneal metastases at 1 year, after removal of the primary mSFT from the right main bronchus.

LESSONS

From these findings, we expect that patients with primary mSFT, especially of the lung, have a high potential to develop second tumors or distant metastases. Close monitoring after surgery is necessary to improve the outcomes of these patients.

Malignant solitary fibrous tumor: cytopathologic findings and differential diagnosis

BACKGROUND

Malignant solitary fibrous tumors (SFTs) are extremely uncommon and poorly understood mesenchymal neoplasms. There are only rare published accounts of the cytopathologic features of these tumors, prompting the current study.

DESIGN

All cases of malignant SFT with preoperative fine-needle aspirations (FNAs) from 1999 to 2008 were retrieved from the archives of 3 large teaching hospitals. FNA smears and cell block material including immunoperoxidase stains were reviewed, and the cytologic characteristics were described.

RESULTS

Thirteen cases of malignant SFT were identified in 11 patients. Mean age was 58 years, with a men:women ratio of 1:2.6. The tumors were generally large, with a mean size of 13.4 cm. Cytomorphologic features included mostly hypercellular smears with tissue fragments of monotonous, plump spindled cells with blunt-ended and indented nuclei and fragile, wispy cytoplasm. Also seen were bare nuclei, occasional mitoses, and rare necrosis. Some cases showed a predominance of epithelioid cells, whereas others displayed a loose myxomatous matrix. There was a general lack of single cells. None of the cases was diagnosed accurately as malignant SFT on FNA, and only 6 cases were called malignant or suspicious for malignancy.

CONCLUSIONS

The FNA diagnosis of malignant SFT is extremely difficult and needs histologic material for accurate interpretation. Predominant FNA diagnoses were SFT or spindle cell neoplasm. Malignant SFT must be included in the differential diagnosis of a spindle cell neoplasm of any anatomic site, particularly if it displays features not typical of benign SFT. Immunoperoxidase staining has some utility, mainly in ruling out other neoplasms in the differential diagnosis.

Extrapleural benign solitary fibrous tumor in the shoulder of a 9-year-old girl: case report and review of the literature

We report a case of a benign solitary fibrous tumor that occurred in the right shoulder of a 9-year-old girl. This case is remarkable due to the unusual location of its occurrence and the young age of the patient. In addition, cytogenetic analysis revealed a karyotype unreported in this neoplasm: 46,XX,der(4)t(4;9)(q31.1;q34), del(9)(p22p24),der(9)t(4;9)(q31.1;q34)ins(9;?)(q34;?) (17 cells)/46,XX (3 cells).

Surgical experience of 15 solitary benign fibrous tumor of the pleura

OBJECTIVE

The localized benign fibrous tumor of the pleura represents 8% of all benign pathologies of the chest and 10% of neoplasms of the pleura. The authors review the literature, and report on 15 cases of localized benign fibrous tumors of the pleura surgically treated over a period of 15 years to further knowledge of this pathology, its therapy and prognosis.

METHODS

With respect to the well-known diffuse malignant mesothelioma, different etiopathogenesis, prognosis, and therapeutic approaches characterize the localized benign fibrous tumor of the pleura. In our experience, 15 patients underwent thoracotomy with excision of a pathological endothoracic mass, then histologically proved to be a localized benign tumor of the pleura. The whole group underwent pre-operative evaluation and, when clinic suggested, stadiation and post-operative frequent follow-up.

RESULTS

The whole group of 15 patients underwent surgical approach well tolerated the surgical treatment with perfect recovery of post-operative respiratory function. There was no relapse of disease in any patients. At the moment all patients are still alive except one dead of heart failure.

CONCLUSION

The differential diagnosis of benign fibrous tumor of the pleura and lung and pleural malignancy depends upon immunohistochemistry of the surgical specimen so that prognosis could be formulated only after surgery. We consider surgery as the treatment of choice in this pathology.

[Giant pleural fibroma]

Solitary fibrous tumors of the pleura are uncommon mesenchymal tumors that have been reported in adults. There are very few cases in children. These tumors are considered benign but their behavior is often unpredictable because they can invade nearby structures and transform into malignant variants after several years. Their clinical presentation is diverse but generally asymptomatic and they are detected incidentally in routine radiologic studies. Prognosis depends firstly on resectability of the tumour and secondly on its size, mitotic count, polymorphism, and necrosis within the tumour. Surgical resection is usually curative. Long-term follow-up is recommended because local recurrences can occur after surgery. We report the case of an asymptomatic 15-year-old girl with a giant thoracic mass revealed incidentally on a chest radiograph. Physical examination revealed thoracic asymmetry and no sounds of breathing were found in the right lung. Computerized tomography and magnetic resonance images showed the giant size of the mass. Preoperative fine needle biopsy was performed. Intraoperative biopsy confirmed the diagnosis. Although histologically benign, the tumors may enlarge rapidly. In the present case, because of the localization and size of the tumor, the patient was at increased risk. The tumour was resected and the postoperative course was uneventful. At present our patient remains under long term annual follow-up.

Solitary fibrous tumors of the pleura

Solitary fibrous tumor of the pleura is a mesenchymal tumor that has been increasingly recognized over the past few years. The tumor was initially described in the pleura, but it has been reported in many other sites lately. Although the majority of these tumors have a benign course, the malignant form still remains enigmatic. Indeed, the behavior of these tumors is often unpredictable and does not always correlate with histologic findings. In addition, benign tumors may remain unproblematic for several years before changing into a malignant form. In order to define more precisely the clinical behavior of solitary fibrous tumors of the pleura, we reviewed the literature with particular attention to the clinical presentation, histopathologic characteristics, and cytogenetic differentiation of these tumors. A staging system and an algorithm for the management and follow-up of these patients are proposed.

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.

Clinicopathological features of solitary fibrous tumor of the meninges: An immunohistochemical reappraisal of cases previously diagnosed to be fibrous meningioma or hemangiopericytoma

Cases of solitary fibrous tumor (SFT) of the meninges are increasingly being reported. However, the real incidence of SFT among meningeal tumors has yet to be determined. We therefore clinicopathologically re-examined 64 meningeal tumors originally diagnosed to be either fibrous meningioma (FM group, n = 46) or hemangiopericytoma (HPC group, n = 18) while paying special attention to SFT. We thus reclassified one case from the FM group (2%) and one case from the HPC group (6%) to be SFT, both of which showed diffuse CD34-immunoreactivity and dense intercellular reticulin fibers but neither epithelial membrane antigen nor S-100 protein expression. The MIB-1 staining index of these cases were 6. 2% and 3.9%, respectively. The former recurred 15 years after the initial surgery and the patient underwent a second removal of the tumor. The patient has been alive with no evidence of recurrence for 7 years after the second surgery. The latter patient has been alive with no evidence of recurrence for 3 years postoperatively. The results confirmed that the incidence of SFT among meningeal tumors is relatively low, however, because of its clinically indolent nature, a careful histochemical examination is necessary to differentiate SFT from other neoplasms with a more aggressive nature. Our findings emphasize the need to clinically recognize this lesion as a distinct entity.

Solitary fibrous tumor of the thoracic spine. Case report and review of the literature

Solitary fibrous tumor (SFT) is a neoplasm first described as a tumor of mesenchymal origin involving soft tissues. The authors provide a review of the literature with detailed pathological analysis and radiological description of SFTs involving the central nervous system. The authors report a rare case of a SFT of the thoracic spine in an adult man presenting with myelopathy. Magnetic resonance imaging revealed a well-circumscribed, intradural, extramedullary mass at the T2-3 level. Histological examination demonstrated a proliferation of predominantly spindle-shaped cells with a collagen-matrix background. Immunohistochemical staining was positive for vimentin and CD34 and negative for S-100 and epithelial membrane antigen with an MIB-1 labeling index of 2.6%. Review of the literature revealed 10 cases in which this tumor, frequently found in the pleura, was involved in the central nervous system. Although rare and their clinical significance as yet unknown, SFTs may be considered in the differential diagnosis of intradural spinal cord lesions. The natural history is also unknown, but these tumors appear to be biologically benign.

Solitary fibrous tumor. A cytologic-histologic study with clinical, radiologic, and immunohistochemical correlations

BACKGROUND

Solitary fibrous tumors (SFT) are rare neoplasms that most commonly involve the pleura, mediastinum, and lung. They are believed to be submesothelial in origin. Histologically, they are characterized by fibroblast-like cells and connective tissue in varying proportions. The "patternless pattern" and the hemangiopericytoma-like pattern are the most common arrangements. The majority of SFTs have been immunoreactive for CD34. Very little has been reported regarding the cytologic findings in these tumors.

METHODS

The authors reviewed the radiographic findings and studied fine-needle aspiration biopsies performed on seven patients with SFT of the pleura, and examined subsequent histologic material. The cell blocks or smears of all cases were stained with a monoclonal antibody to CD34.

RESULTS

The cytologic preparations showed varying degrees of cellularity. Smears were comprised of spindled cells in a bloody background with small amounts of collagen. The three malignant tumors had a greater number of cells, both dispersed and in clusters, with nuclear pleomorphism and prominent nucleoli. The cell blocks characteristically showed varying degrees of cellularity with thickened blood vessels and a hemangiopericytoma-like pattern. The cells from the four benign tumors tended to be smaller in size and grouped in more cohesive clusters than the malignant ones. CD34 stained the spindle tumor cells in the cell blocks or smears from five cases; one malignant and one benign case failed to stain. The corresponding histologic samples from these cases demonstrated the same CD34 staining pattern in all cases except one.

CONCLUSIONS

The differential diagnosis of SFT includes neurogenic tumors, mesotheliomas, sarcomatoid carcinoma, synovial sarcoma, hemangiopericytoma, and fibrosarcoma. CD34, when present, may prove equally helpful as a positive marker in cytology and in histologic preparations in the differential diagnosis of SFT.

Solitary fibrous tumor of the spinal cord

We report a case of primary solitary fibrous tumor occurring in the intramedullary thoracic spinal cord in a 47-year-old man. The tumor predominately consisted of spindle cells separated by abundant collagen; a few areas of hemangiopericytomatous morphology were also present. The diagnosis was confirmed by immunohistochemistry and electron microscopy. The tumor was reactive to vimentin and CD34 but was negative for glial fibrillary acid protein (GFAP), S-100, smooth muscle actin, epithelial membrane antigen, HMB-45, myelin basic protein, and keratin; ultrastructural examination showed fairly undifferentiated cells within a collagenous matrix, few tight junctions, and sparse extravascular basement membrane. The occurrence of this tumor within the spinal cord parenchyma and in other extraserosal sites emphasizes the current belief that solitary fibrous tumors arise from mesenchymal tissues and are not restricted to the pleura and other serosal surfaces. Furthermore, solitary fibrous tumor is an entity that must be considered in the differential diagnosis of spindle cell central nervous system neoplasms.