Solitary fibrous tumors of soft tissue. A clinicopathologic and immunohistochemical study of 12 cases

[Solitary fibrous tumor of the urinary bladder: a case report]

Solitary fibrous tumor (SFT) is one of the mesenchymal tumor usually occurs in the pleura. Extrapleural occurrence of SFT is uncommon. We herein report an extremely rare case of 72-year old man with SFT originated in the urinary bladder. The tumor was incidentally discovered as a mass of 8.5 mm in diameter by a pelvic MRI. Cystoscopy revealed the protruding submucosal tumor in the center of the trigon. Transurethral resection was carried out. Pathological examination revealed a tumor composed of spindle cells with rich vascularity surrounded by abundant collagen fibers. The immunohistochemical findings showed a strong positivity to CD 34 and relatively weak positivity to Bcl-2. MIB-1 index indicated less than 3%, thus the tumor was diagnosed as a solitary fibrous tumor. The patient has no evidence of disease 16 months after the surgery. The current case was the first report in Japan and the twelfth worldwide.

Dendritic myxofibrolipoma: often misdiagnosed as sarcoma

The author describes a benign soft tissue tumor that could be easily mistaken for sarcoma. It represents a combined feature of solitary fibrous tumor and spindle cell lipoma. The clinical presentation, diagnosis, and management of this lesion are discussed. It highlights the importance of proper diagnosis to prevent unnecessary and ineffective treatment by clinicians as the complete excision of this lesion is the treatment of choice and recurrence is very unlikely. It is believed that this case is the first reported case of dendritic myxofibrolipoma occurring in the lower lip mucosa in an Omani patient.

Solitary fibrous tumor of filum terminale

Solitary fibrous tumor (SFT) is a mesenchymal neoplasm that most commonly arises from the visceral or parietal pleura. Solitary fibrous tumor with a primary site in the filum terminale has not been reported previously in the literature. Here we report a case of SFT occurring in the filum terminale. The characteristic imaging feature of this tumor is hypointensity on T2-weighted images. Even though rare, SFT should be considered in the differential diagnosis of tumors occurring intraspinally, even in the filum terminale.

Retroperitoneal schwannoma is characterized by a high incidence of cellular type and GFAP-immunoreactivity

To clarify the clinicopathologic characteristics of retroperitoneal schwannomas, which are sometimes confused with other spindle cell tumors, 27 cases were studied microscopically and immunohistochemically. The 27 cases consisted of 17 females and 10 males, the ages of whom ranged from 31-79 (mean 57.4) years. Gross examination revealed well-demarcated, encapsulated tumors, 3-15 cm (mean 8 cm) in diameter. Microscopic review divided them into 13 cases of cellular/fascicular, 3 of conventional, 6 of intermediate, and 5 of ancient type. Cellular/fascicular schwannomas were composed of cellular fascicles of spindle cells, in which nuclear palisading, Antoni B area and cyst were unclear, while numerous foamy cells were intermingled. Immunohistochemical investigation revealed diffuse, strong positivity for S-100 protein and Sox10 in all tumors studied. In addition, glial fibrillary acidic protein (GFAP) was extensively expressed in 92% of the cellular/fascicular type, while it was less prominent in others. The present study suggests that retroperitoneal schwannoma often occurs in the middle-aged woman, grows to a large size, exhibits cellular/fascicular microscopic features in half of the cases, and may arise from GFAP-positive Schwann cells. The presence of hyalinized vessels and dense infiltration of foamy macrophages as well as diffuse immunoreactivity for S-100 protein and Sox10 are helpful for the differential diagnosis.

A locally aggressive solitary fibrous tumor of the leg: Case report and literature review

INTRODUCTION

The solitary fibrous tumor (SFT) is a rare soft tissue tumor with a substantially benign clinical behavior. However, malignant neoplasms with local recurrence or distant metastases have been reported.

PRESENTATION OF THE CASE

The authors present a case of an aggressive SFT of the leg, in a 55 years old Caucasian man. Radiological, histological and molecular findings are reported. The differential diagnosis, therapy and outcome of this rare tumor are also discussed.

DISCUSSION

An extensive review of literature showed SFT's clinical behavior as substantially benign, anyway aggressive or malignant neoplasms have been described. The potential risk of local recurrence and distant metastasis thus suggests wide surgical resection and careful long-term follow-up. Differential diagnosis may be quite laborious as SFT can mimic a variety of benign and malignant mesenchymal tumors; immunohistochemical analysis for CD34, CD99, vimentin and bcl-2 is then mandatory.

CONCLUSION

Our clinical experience confirmed that SFT may have an aggressive behavior, however, conservative surgical treatment may be successful in the long term.

Solitary fibrous tumor: an update on the spectrum of extrapleural manifestations

Solitary fibrous tumor (SFT) is a rare tumor initially believed to be a benign localized pleural tumor of mesothelial origin. Over the past few years, the literature on this tumor has grown tremendously. The tumor is now reported in diverse bodily locations, and recognized to have a wider range of clinical and radiological features. The most common extrapleural sites of the tumor are the orbits and the extremities. Tumors are often well-circumscribed masses, and vary in size from 1 cm to over 30 cm. The admixture of histological components in the tumor, namely, fibrous tissue, cellular components, and highly vascularized areas consisting of numerous closely packed small to medium-sized blood vessels, influence the imaging appearances of the tumor. On magnetic resonance imaging (MRI), the diagnosis of solitary fibrous tumor is suggested by a well-circumscribed mass that has smooth margins, and focal or diffuse hypointense signal on T2-weighted imaging due to fibrous content in the tumor. SFTs demonstrate strong focal or diffuse contrast enhancement due to the highly vascularized areas in the tumor.

Parotid gland solitary fibrous tumor: a case report and clinicopathologic review of 22 cases from the literature

Solitary fibrous tumors (SFTs) are rare tumors in the head and neck, and even more so in the parotid gland. The mass-like clinical presentation and histologic features result in frequent misclassification, resulting in inappropriate clinical management. There are only a few reported cases in the English literature. Twenty-one patients with parotid gland solitary fibrous tumor were compiled from the English literature (Medline 1960-2011) and integrated with this case report. The patients included 11 males and 11 females, aged 11-79 years (mean, 51.2 years), who presented with a parotid gland painless mass gradually increasing in size or with compression symptoms, with a mean duration of symptoms of 24.7 months. The mean tumor size was 4.5 cm. Grossly, all tumors were described as well-circumscribed to encapsulated, firm, homogenous white to tan masses. Seven patients had a preoperative fine needle aspiration performed, with the majority interpreted to represent pleomorphic adenoma or cementifying fibroma. Histologically, the tumors were well circumscribed, although many tumors showed focally entrapped normal salivary gland acini and ducts at the edge. The tumors were cellular, arranged in haphazard short interlacing fascicles of spindled to epithelioid cells. The spindled cells showed tapering cytoplasm with monotonous, round to oval nuclei with coarse nuclear chromatin distribution. Keloid-like to wiry collagen was present between the neoplastic cells. Mitoses were identified in most cases, while necrosis was absent. Isolated, patulous vessels were present, but a well developed "hemangiopericytoma-like" vascular pattern was not seen. Three tumors were classified as malignant, showing marked nuclear pleomorphism and increased mitoses. When immunohistochemistry was performed, all tumors showed strong and diffuse vimentin, with a majority showing CD34, bcl-2 and CD99 immunoreactivity; all cases tested were negative for S100 protein, cytokeratin, EMA, CAM5.2, smooth muscle actin, muscle specific actin, desmin, MYOD1, myogenin, CD117, GFAP, CD31, FVIII-RAg, collagen IV, p63, p53, calponin, caldesmon, CD56, NFP, and ALK-1. The principle differential diagnoses include pleomorphic adenoma, myoepithelioma, nodular fasciitis, schwannoma, fibromatosis coli, spindle cell "sarcomatoid" carcinoma, and spindle cell melanoma. All patients were managed with surgery, while two patients also received radiation therapy. Metastatic disease was identified in one patient immediately after excision. All patients with follow-up were alive without evidence of disease (n = 18), but the average follow-up is only 1.9 years. One patient is alive with disease at 12 months. Parotid gland SFT is a rare tumor, usually presenting in middle aged adults as a slowly growing mass. Characteristic histologic appearance with CD34 and bcl-2 immunoreactivity support the diagnosis. Surgery is the treatment of choice to yield a good outcome.

Solitary fibrous tumor of the central nervous system: a 15-year literature survey of 220 cases (August 1996-July 2011)

We reviewed the world literature on solitary fibrous tumors of the central nervous system from August 1996 to July 2011, focusing on both clinicopathological features and diagnostic findings. The anatomical distribution of the 220 cases reported so far reveals that most are intracranial and just over one-fifth are intraspinal. In decreasing frequency, intracranial tumors involve the supratentorial and infratentorial compartments, the pontocerebellar angle, the sellar and parasellar regions, and the cranial nerves. Intraspinal tumors are mainly located in the thoracic and cervical segments. Although most solitary fibrous tumors of the central nervous system are dural based, a small subset presents as subpial, intraparenchymal, intraventricular, or as tumors involving the nerve rootlets with no dural connection. Preoperative imaging and intraoperative findings suggest meningioma, schwannoma or neurofibroma, hemangiopericytoma, or pituitary tumors. Immunohistochemistry is critical to establish a definitive histopathological diagnosis. Vimentin, CD34, BCL2, and CD99 are the most consistently positive markers. The usual histologic type generally behaves in a benign manner if complete removal is achieved. Recurrence is anticipated when resection is subtotal or when the tumor exhibits atypical histology. The proliferative index as assessed by MIB1 labeling is of prognostic significance. Occasionally, tumors featuring conventional morphology may recur, perhaps because of minimal residual disease left behind during surgical extirpation. Rare extracranial metastases and tumor-related deaths are on record. Surgery is the treatment of choice. Stereotactic and external beam radiation therapy may be indicated for postsurgical tumor remnants and for unresectable recurrences. Long-term active surveillance of the patients is mandatory.

Solitary Fibrous Tumor of the Central Nervous System

Solitary fibrous tumor (SFT) of the central nervous system was first described in 1996. A number of cases have been reported since. The authors present 5 new cases: 4 intracranial and 1 intraspinal. All patients were adults (age range, 47 to 75 years); 4 were male and 1 female; 4 cases were primary tumors; and 1 was a second tumor recurrence. All patients were surgically treated with gross total removal. All cases were histologically examined with immunohistochemical confirmation; 2 tumors exhibited diffuse classic histology, 1 tumor was a cellular variant, 1 tumor was myxoid, and 1 was predominantly classic with focal myxoid features and focally pleomorphic. The postoperative course was uneventful in all. The patient with the cellular variant experienced 2 local recurrences and eventually died of disease 10 years after the initial diagnosis. The patient with the myxoid variant—the tumor studied—which was the second recurrence of a previously misdiagnosed fibrous meningioma surgically treated 15 years earlier, had a recurrence after 2 years for the third time and eventually died of disease. Three patients are alive and well 11.6, 6, and 4 years after surgery. SFT is a rare tumor that needs to be differentiated from some mimickers, mainly fibrous meningioma, hemangiopericytoma, and with regard to the myxoid variant, also adult-onset myxochordoid meningioma and myxoid peripheral nerve sheath tumor. Immunohistochemistry is crucial for the correct diagnosis of SFT. The authors also performed a review of the literature and found a little more than 200 cases on record.

Angiofibroma of the spermatic cord: a case report and a review of the literature

Introduction

Cellular angiofibroma is a benign vascular neoplasm that typically arises in the paratesticular region in men and is easily confused with inguinal or scrotal hernia.

Case presentation

We present a case of a cellular angiofibroma arising from the spermatic cord of a 74-year-old Caucasian man. Initially, the lesion was confused with a scrotal hernia, but imaging revealed a subcutaneous, inhomogeneous, but well-circumscribed lesion to the surrounding tissues with rich vasculature. Surgical resection of the lesion was performed. Histology revealed a benign tumor of vascular origin rich in fibroblasts.

Conclusions

Angiofibroma can easily be confused with an inguinal hernia and should be differentiated from Schwann cell tumors, perineuromas, spindle-cell lipomas, aggressive angiomyxomas, angiomyofibroblastomas, solitary fibrous tumors, spindle-cell liposarcomas, and leiomyomas. A safe initial diagnosis is difficult because of its location, nature, and correlation with other structures of the area.

Somatic and visceral solitary fibrous tumors in the abdomen and pelvis: cross-sectional imaging spectrum

Solitary fibrous tumors (SFTs) are a unique group of mesenchymal neoplasms of fibroblastic or myofibroblastic origin. These tumors were originally described as "benign fibrous mesotheliomas" of the pleural cavity and were erroneously thought to be confined to the serosal surfaces (due to a putative mesothelial or submesothelial origin). It is now established that SFTs are ubiquitous neoplasms with both pleural and extrapleural distribution. Extrapleural SFTs commonly occur in middle-aged adults and manifest as asymptomatic, slow-growing, large tumors. Fewer than 5% of patients with SFTs present with symptomatic hypoglycemia. SFTs are histopathologically diverse with a variable admixture of fibroblasts or myofibroblasts, numerous thin-walled vessels, and dense fibrosis. Tumors previously categorized as hemangiopericytomas are now considered cellular variants of SFTs. At imaging, SFTs demonstrate remarkable heterogeneity, with variable degrees of enhancement, necrosis, or hemorrhage. Although most extrapleural SFTs have a benign clinical course, 10%-15% of these tumors demonstrate aggressive behavior in the form of recurrence or malignancy.

Efficacy of trabectedin in metastatic solitary fibrous tumor

Solitary fibrous tumor is a rare tumor type and has an unpredictable course. Local recurrence rate varies between 9 and 19%, and rate of metastatic involvement between 0 and 36 %. It is characterized by a typical architecture and immuno-histochemistry tests. The most important prognostic factor is the complete resection of primary tumor. Treatment of recurrences is not clearly established. If a solitary fibrous tumor is too advanced to allow surgical resection, radiotherapy and chemotherapy may be used. The most often used drugs are doxorubicine and\or ifosfamide. We report the case of man with metastatic solitary fibrous tumor treated with trabectedin, administered at a dose of 1.5 mg/m² every 3 weeks. After 3 cycles, metastases had significantly decreased. Recurrence of the disease was demonstrated 8 months after the start of trabectedin. This case shows that trabectedin is a possible treatment option.

Solitary Fibrous Tumor of the Vagina

Solitary fibrous tumor, initially described in the pleura, is now known to occur in various extrathoracic sites. However, its occurrence in the female genital tract, especially the vagina, is extremely rare. The authors report here a case of a well-circumscribed vaginal spindle cell nodule in a 48-year-old woman with features consistent with solitary fibrous tumor. The diagnosis was established histologically by the varying pattern with hypocellular fibrous areas alternating with hypercellular areas and hemangiopericytoma-like areas and, immunohistochemically by the strong positive reaction for CD34 and Bcl2 with a negative reaction for all other spindle cell and epithelial markers. The differential diagnosis is discussed and a review of the literature is presented.

[Solitary fibrous tumors: Case report of a late relapse]

Authors report a case of a woman with a metastasis of a solitary fibrous tumor, 14 years after the diagnosis of a hemangiopericytoma of the soft tissues. This case report allows discussing the pathological features, the therapeutical option and the outcome of these tumors.

Surgical resection using retroperitoneal approach for solitary fibrous tumor in the pelvis

This report concerns a case of solitary fibrous tumor (SFT) for which surgical resection was performed using a retroperitoneal approach. A 41-year-old man was referred to our hospital with urinary retention. Abdominal ultrasound sonography (US) and computed tomography (CT) showed a hypervascular mass lesion in the pelvis. Transrectal biopsy showed SFT. Surgical resection was carried out using a retroperitoneal approach and preserving the neural network related to urinary and erectile functions. Based on immunohistochemical findings, the tumor was diagnosed to be malignant SFT in the pelvic cavity. Urinary function improved post-operation. There was no change to IIEF-5 and it continued to function well. The patient showed no sign of recurrence 12 months after surgery and required no additional therapy.

Bifrontal solitary fibrous tumor of the meninges

Background:

We report the case of a bifrontal solitary fibrous tumor (SFT) arising from the meninges. The points of interest in this case report are the particular imaging appearance, the immunohistochemical findings and the surgical features.

Case Description:

A 53-year-old Caucasian male presented with a 1-year history of behavioral changes, attention disorders and anterograde memory disorders. Magnetic resonance imaging revealed a bifrontal heterogeneous lesion attached to the anterior falx cerebri with a prominent multicompartmental cystic part. The patient underwent craniotomy for a sub-total resection of the tumor. At surgery, the multicystic component was highly vascularized and encased the anterior cerebral arteries. Neuropathological findings were consistent with a solitary fibrous tumor. Despite the absence of malignant features, there was a focal expression of p53.

Conclusion:

SFT is a pathological entity with specific immunohistochemical features; it has frequently been misdiagnosed in the past. The multicystic imaging appearance of this SFT and the particular p53 immunohistochemical staining are features that should be added to the growing data on intracranial SFTs. The surgical features described (high vascularization and partial vessel encasement) may help improve surgical planning.

Imaging appearance of solitary fibrous tumor of the abdominopelvic cavity

The computed tomographic or magnetic resonance imaging appearance of solitary fibrous tumors of the abdominopelvic cavity has previously only been presented in the English literature as individual case reports. In this article, we present the cross-sectional imaging appearance of 5 such cases, all of which exhibited highly similar imaging features, including well-circumscribed margins, lack of invasion of adjacent structures, and avid enhancement. In view of these shared imaging features, it may be possible to suggest the diagnosis preoperatively. Given their unpredictable biologic behavior with infrequent reports of recurrent or metastatic disease, complete surgical excision and long-term follow-up for these lesions is recommended.

A rare case of giant solitary fibrous tumor of the esophagus

Giant solitary fibrous tumor of the esophagus is a very rare neoplasm. We herein report a successful surgically treated solitary fibrous tumor of the esophagus. A 49-year-old man presented with a history of difficulty in swallowing and chest pain. The preoperative diagnostic workup, including a computed tomographic chest scan, endoscopy, endoscopic ultrasonography, and barium swallow, demonstrated a giant pedunculated intraluminal mass in the esophagus. The tumor was completely resected through a transthoracic esophagotomy, combined with an intraoperative endoscopy. A microscopic examination and immunohistochemical studies supported the diagnosis of a benign solitary fibrous tumors of the esophagus. The patient remained well with no evidence of recurrence 16 months after surgery.

Oral solitary fibrous tumor: a cytogenetic analysis of tumor cells in culture with literature review

Solitary fibrous tumor (SFT) is an uncommon spindle-cell neoplasm of mesenchymal origin. Because the pathogenetic background of SFT is still controversial, cytogenetic analysis could help in tumor diagnosis and prognosis. In this study, cultured SFT cells from a lower lip lesion that presented characteristic immunopositivity for CD34, vimentin, CD99, and BCL2 showed a unique cytogenetic finding: 46,XX,inv(2)(p21q35),t(3;12)(q25;q15). To our knowledge, this is the third report of cytogenetic result of a case involving the oral cavity. The SFT cells in culture that maintained their immunohistochemical expression of diagnostic molecules, showed unique chromosomal changes previously unreported when compared with already documented ones. Our data suggest that the complicated pathogenetic nature of SFT is possibly tumor- or organ-related.

Extrapleural solitary fibrous tumor: a clinicopathologic study of 19 cases

This study reports a series of 19 extrapleural solitary fibrous tumors. The patients included 6 men and 13 women with age ranging from 27 to 86 years. Three patients showed local recurrence. In 2 tumors, a diagnosis of malignancy was made. All of the tumors were strongly positive for CD34, and 3 of them expressed high levels of progesterone receptor. Solitary fibrous tumors are fairly rare, occurring in many parts of the body, and their behavior is unpredictable.

Solitary fibrous tumor of the oral cavity: clinicopathologic and immunohistochemical study of 21 cases

We describe clinical, morphologic, and immunohistochemical features of 21 cases of solitary fibrous tumor presenting in the oral cavity. There were 9 male and 12 female patients with a median age of 51 years (range 37-83). The most common locations included the buccal mucosa (the most common site), lip, maxillary or mandibular vestibule and tongue. Histopathologic examination showed well-circumscribed tumors with two well-defined patterns: the classic pattern with densely cellular areas alternating with hypocellular areas in a variably collagenous, vascular stroma and a more uniformly sclerotic pattern with only subtle classic areas. The spindle-shaped neoplastic cells consistently showed immunoreactivity for antibodies directed against CD34. Five of nineteen cases (26%) were reactive for CD99 and 19 of 19 for Bcl-2. Follow-up information was available in 17 cases and averaged 54 months, with no evidence of recurrence or metastasis in any of these patients. Awareness that solitary fibrous tumor may present in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided. We also briefly describe the differential diagnosis and compare this series, the largest single series of intraoral SFT, to cases previously reported in the literature.

Solitary fibrous tumor of the male pelvis: findings at CT with histopathologic correlation

We present CT imaging findings with pathologic correlation in a rare case of a solitary fibrous tumor arising in the pelvis in a 34-year-old man. This tumor presented as a hypervascular heterogeneously enhancing deep pelvic mass at CT. Although CT initially suggested the prostate as the site of origin for this tumor, no prostate involvement was found at surgery; CT accurately excluded bladder and rectal involvement.

Dermatofibrosarcoma protuberans presenting as a subcutaneous mass: a clinicopathological study of 15 cases with exclusive or near-exclusive subcutaneous involvement

Dermatofibrosarcoma protuberans (DFSP), a cutaneous fibrohistiocytic tumor of intermediate (borderline) malignancy, typically arises in the dermis and subsequently infiltrates the subcutaneous tissue. Very rarely DFSP may either arise within the subcutaneous fat without dermal involvement or show very extensive subcutaneous involvement with only minimal and clinically subtle dermal involvement. We present the clinicopathological features of 15 cases of DFSP showing exclusive or near-exclusive involvement of the subcutaneous fat. The differential diagnosis with other subcutaneous spindle cell neoplasms is emphasized. Awareness of this rare subset of DFSP should prevent its misdiagnosis as other less aggressive tumor types.

Solitary fibrous tumor (SFT) of the pelvis

Solitary fibrous tumors (SFTs) are well recognized in the pleura, but their occurrence at other sites has only become appreciated in recent years, as a consequence of which extrapleural examples often go unrecognized and misdiagnosed. Because of their rarity, overall experience concerning this tumor has not been significant and reports detailing radiological findings are few. We herein report an unusual case of a large retroperitoneal pelvic SFT with features of high vascularity negating successful surgical resection.

Solitary fibrous tumor of the larynx

BACKGROUND

True mesenchymal, non-cartilaginous neoplasms of the larynx are rare. Extrapleural solitary fibrous tumor (SFT) is a localized neoplasm characterized by proliferation of thin-walled vessels and collagen-producing cells and is considered within the "hemangiopericytoma-solitary fibrous tumor" spectrum. SFT primary in the larynx is exceptional.

DESIGN

Case report set in a comparison with other cases reported in the English literature (MEDLINE 1966 to 2007).

RESULTS

A 49-year old white male presented with difficulty breathing, progressive over the past 2 years. He denied dysphagia and weight loss. Past medical history was significant for asthma. He denied cigarette smoking or alcohol abuse. There were no cervical deformities on physical exam. Fiberoptic laryngoscopy was performed upon stabilization of respiratory function. A smooth, round, submucosal mass measuring 2.3 cm in greatest diameter arising from the inferior surface of left true vocal cord was causing near total obstruction of the endolaryngeal space. The mass was excised. The surface mucosa was intact and unremarkable. A cellular, spindle cell neoplasm was arranged in loose fascicles, associated with heavy collagen fiber deposition. The collagen was wiry and heavy. Cells were bland with cytoplasmic extensions. The nuclei were vesicular to hyperchromatic and elongated with inconspicuous nucleoli. Vessels were prominent and delicate, with patulous spaces. Mitotic figures were easily identified, but atypical forms were not present. The cells were strongly and diffusely immunoreactive with CD34 and bcl-2, while non-reactive with cytokeratin, EMA, actin, ALK-1, S100, desmin, and CD117. These findings confirmed a diagnosis of extraplural solitary fibrous tumor. Without further disease, the patient is alive without evidence of disease, 12 months after surgery.

CONCLUSIONS

The characteristic histologic pattern of solitary fibrous tumor can be noted in extrapulmonary locations. Development in the larynx is uncommon, but the tumor presents as a polypoid mass with characteristic histologic and immunophenotypic features. Conservative local excision is the treatment of choice to yield an excellent prognosis.

Solitary fibrous tumor of the orbit: CT and MR imaging findings

BACKGROUND AND PURPOSE

Solitary fibrous tumor (SFT) is a rare spindle-cell neoplasm originating from mesenchymal fibroblast-like cells. The purpose of this study was to describe the CT and MR imaging features of SFTs in the orbit.

MATERIALS AND METHODS

We retrospectively reviewed CT and MR images in 6 patients (2 men and 4 women), aged 18 to 51 years, with SFT proved on histologic examination located in and around the orbit. All patients underwent CT (including dual-phase CT in 3), and MR imaging was obtained in 3. We evaluated the imaging findings with emphasis on the location, size, margin, internal architecture, and pattern of enhancement of the lesion.

RESULTS

All 6 lesions were found as a solitary, well-defined mass, ranging in size from 18 to 30 mm (mean, 24 mm). Three were located in the postseptal orbit, 2 in the lacrimal sac, and 1 on the lower eyelid. Compared with the cerebral cortex, all 3 lesions examined by MR imaging showed homogeneous isointense signal intensity on T1-weighted images and heterogeneous mixed isointense and hyperintense signal intensity on T2-weighted images. On visual inspection, all 6 lesions showed marked homogeneous (n = 4) or heterogeneous (n = 2) enhancement on postcontrast CT and MR images. In 3 patients examined with dual-phase CT, all lesions demonstrated rapid enhancement with early washout of contrast material.

CONCLUSION

SFT might be included in the differential diagnosis of soft tissue masses in the orbit, if one sees a markedly enhancing mass showing the similar characteristics to those of the internal carotid artery on postcontrast CT or MR images.

Application of immunohistochemistry to soft tissue neoplasms

CONTEXT

Soft tissue tumors are composed of numerous and complex diagnostic entities. Because of this complexity and the recognition of an intermediate malignancy category including some tumors with a deceptively bland histologic appearance, soft tissue tumors may represent a major diagnostic challenge to the general practicing pathologist.

OBJECTIVE

To correctly diagnose soft tissue tumors with the ancillary use of immunohistochemistry.

DATA SOURCES

Review of the current literature with emphasis on those tumors for which immunohistochemistry has proven to be particularly useful.

CONCLUSIONS

Immunohistochemistry plays an important role in the diagnosis of soft tissue tumors. One of its major utilities is to correctly identify a tumor as being of mesenchymal or nonmesenchymal origin. Once mesenchymal origin has been established, histologic subtyping according to specific cell lineage may be achieved with the use of lineage-specific markers. Tumors of uncertain cell lineage and tumors with primitive small round cell morphology are often characterized by a unique immunohistochemical phenotype. In this group of tumors, immunohistochemistry is most widely applied and is of greatest value. Despite the rapid development of molecular genetic techniques, immunohistochemistry still remains the most important diagnostic tool in the diagnosis of soft tissue tumors aside from recognition of morphologic features and clinical correlation.

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 male breast: a case report and review of the literature

Extrapleural solitary fibrous tumors are very rare and occasionally they appear in extraserosal soft tissues or parenchymatous organs. In such cases the right preoperative diagnosis is often difficult and challenging, because both radiological and cytological examinations are not exhaustive. For these reasons, surgical excision is frequently the only way to reach the correct diagnosis and to achieve definitive treatment. A few cases of solitary fibrous tumors have been also described in the breast. Although rare, this lesion opens difficulties in preoperative diagnosis entering in differential diagnosis with other benign lesions as well as with breast cancer. In this article we describe a case of a solitary fibrous tumor of the breast in a 49-year-old man. Problems related to differential diagnosis and the possible pitfalls that can be encountered in the diagnostic iter of such rare tumor are discussed.

Comparison of sporadic sclerotic fibroma and solitary fibrous tumor in the oral cavity

Sporadic sclerotic fibroma (SF) and solitary fibrous tumor (SFT) arising in the oral cavity are very rare. In this report, we describe two cases of oral pathology, one involving SF and the other involving SFT. Both cases presented with well- circumscribed, firm nodules with similar gross findings. However, the histologic findings of the SF and SFT showed rather distinct features. The SF was composed of hyalinized sclerotic collagen bundles arranged in a whorled pattern, whereas the SFT was formed by spindles cells arranged in hypo- and hypercellular areas. The immunohistochemical findings were similar in both cases; there was positivity for vimentin, CD34, and CD99, but bcl-2 positivity was only seen in the SFT. Although their histopathologies are similar, SF and SFT should be considered in the differential diagnosis of soft tissue tumors in the oral cavity.

Solitary Fibrous Tumor on Needle Biopsy and Transurethral Resection of the Prostate

One of the least commonly encountered spindle cell tumors seen on prostatic needle biopsy or transurethral resection (TUR) of the prostate is solitary fibrous tumor (SFT). We studied 13 cases of SFTs identified on either prostate needle biopsy (n=9) or TUR of the prostate (n=4). Mean patient age at diagnosis was 63 years (range: 46 to 75 y; median: 65 y). Twelve men presented with urinary tract symptoms and 1 patient was biopsied during work-up of bone metastases. Ten cases were SFTs originating in the prostate, 2 cases arose between the prostate and rectum extending into the prostate (n=2), and 1 case was a pelvic mass without infiltration of the prostate. In 9 cases, a complete tumor resection was attempted by cystoprostatectomy (n=2), radical prostatectomy (n=4), pelvic exenteration (n=2), or pelvic tumor resection (n=1). Enucleation (n=1) and TUR (n=1) were performed in 2 other cases. Tumor sizes ranged from 8.5 to 15 cm in 7 radically resected cases. Mitotic rates were 3 to 5 per 10 high power fields in 5 cases, with the remaining cases having either rare (n=4) or no mitoses (n=4). Seven cases demonstrated areas of necrosis. Based on a combination of increased cellularity, mitotic activity, necrosis, nuclear pleomorphism, and infiltrativeness, 4 prostatic SFTs were malignant, 4 were benign, and 2 were borderline. Of the 3 non-prostatic SFTs, 1 was malignant and 2 were borderline. All tumors but 1 were immunoreactive for CD34 (n=12). Material for additional immunohistochemistry was available for the majority of cases with positive stains for Bcl-2 (11/11), CD99 (7/10), beta-catenin (5/10), and c-kit (0/11). Three SFTs demonstrated >or=10% p53 immunoreactivity including 1 tumor with 50% positivity; and 3 cases had Ki-67 rates of >or=20%. Although all SFTs were initially clinically considered to be of prostatic origin, some of the cases arose in the pelvis with secondary involvement of the prostate. Approximately 50% of prostatic SFTs were malignant. Even in the prostatic and nonprostatic SFTs with no overt malignant features, sometimes it was necessary to remove the prostate and in some instances the adjacent organs because of the large size of the tumors. SFTs must be differentiated from other spindle cell neoplasms of the prostate especially from gastrointestinal stromal tumors that may arise from the rectal wall with invasion of the prostate or from the region between the rectum and the prostate.

Angiomyofibroblastoma-like tumor (cellular angiofibroma) in the male inguinal region

Angiomyofibroblastoma-like tumor is a rare mesenchymal tumor involving the male genital tract. We report a case of an angiomyofibroblastoma-like tumor that arose in the subcutaneous tissue of the left inguinal region in a 50-year-old man. Ultrasonography of the region demonstrated a well-circumscribed subcutaneous mass. Intralesional fat was revealed on magnetic resonance images. Although these imaging features are nonspecific, radiological findings enable considering the diagnosis of angiomyofibroblastoma-like tumor.

SOLITARY FIBROUS TUMORS OF THE CENTRAL NERVOUS SYSTEM

OBJECTIVE

This is a retrospective study of 18 patients harboring a solitary fibrous tumor of the central nervous system. Therapeutic management and outcome were analyzed.

METHODS

Between 1999 and 2004, 18 patients harboring central nervous system solitary fibrous tumors were surgically treated at our two institutions. There were nine men and nine women. The patient ages ranged from 33 to 75 years, with a median age of 56.1 years. The locations were spinal in six cases (33.3%), the posterior fossa in six cases (33.3%), supratentorial in four cases (22.2%), and orbital in two cases (11.2%).

RESULTS

The median follow-up period was 45.3 months. Gross total resection was achieved in 10 cases (55.6%); tumor recurrence or progression occurred in nine cases (50%). Incomplete surgical resection was significantly associated with recurrence (P = 0.018). On univariate analysis, extent of surgery was also associated with a longer progression-free survival (P = 0.05). No statistically significant correlation can be found between histological features and recurrence.

CONCLUSION

Prognosis of solitary fibrous tumors of the central nervous system remains unclear; consequently, careful and close monitoring of patients and long-term follow-up are mandatory. Radical surgical excision seems to be a significant and reliable prognosis factor, although pathological prognostic features must be defined. In other respects, the role of postoperative radiotherapy in atypical or incompletely resected solitary fibrous tumors of the central nervous system remains to be determined and, therefore, warrants larger series with longer follow-up periods.

Solitärer fibröser Tumor der Zunge

Solitary fibrous tumors (SFT) are rare, mostly fibroblastic tumors usually situated in the pleura. Extrapleural manifestations have been described. However, the oral cavity is an uncommon localisation of this tumor. We report the very unusual case of an SFT affecting the tongue that could be removed completely because of its clear delineation. Intraoperative incisional biopsies were used to exclude malignancy. For definitive classification of the tumor, additional histopathologic examinations had to be carried out. Because SFT exhibit malignant behavior only in exceptional cases and their recurrence after complete removal has never been encountered, surgery can focus on the preservation of undisturbed function of the tongue.