Solitary fibrous tumor of the oral cavity: an uncommon location for a ubiquitous neoplasm

Anterior mediastinal solitary fibrous tumor resection by da Vinci® Surgical System in obese patient

INTRODUCTION

Solitary fibrous tumors are uncommon soft tissue tumors initially reported only in the pleura but, in recent years, they have been described at many extra pleural sites, such as mediastinum. The treatment of choice is the extensive surgical resection that is curative for most benign lesions.

PRESENTATION OF THE CASE

We present the case of solitary fibrous tumor of the anterior mediastinum in obese patient (BMI: 34.3) undergoing complete surgical resection by robotic-assisted thoracoscopic surgery with da Vinci^® Surgical System.

DISCUSSION/CONCLUSION

Robotic-assisted thoracoscopic surgery with da Vinci^® Surgical System is an interesting option for obese patient, at higher risk for deep sternal wound infection.

Solitary fibrous tumor of the buccal vestibule: report of two cases

Solitary fibrous tumor (SFT) is a rare benign tumor that occurs most frequently in the pleura. It is considered rare in the maxillofacial area. Two new cases of SFT of the buccal vestibule are reported. The previously reported cases of oral SFT are reviewed. The tumors were composed of spindle-shaped cells that were arranged haphazardly and were positive for CD-34, BCL-2, CD-99 and vimentin. Although rare, SFT should be included in the differential diagnosis of oral soft tissue tumors. The clinical presentation and imaging can provide the clinician a better tool for preoperative diagnosis.

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.

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 Tumor of the Parapharyngeal Space

Solitary fibrous tumors are benign neoplasms of mesenchymal origin. They usually arise from the visceral or parietal pleura and peritoneum, although they have been found in many areas throughout the body. We report a case of solitary fibrous tumor of the parapharyngeal space. Microscopically, the tumor contained spindle cells with areas of marked hypercellularity without a definite pattern. Consistent with a benign lesion, there were few mitoses and no necrosis. The tumor cells stained strongly positive for CD34 and vimentin. At the 2-year follow-up, the patient was well and free of local and/or distant disease.

Solitary fibrous tumour of the buccal mucosa: Case report and review of the literature

Solitary fibrous tumours are spindle-cell neoplasms that usually occur in the pleura and peritoneum, and rarely involve the oral mucosa. We report a 30-year-old man with a large solitary fibrous tumour on the buccal mucosa that resembled a salivary gland neoplasm. The lesion was excised and has not recurred.

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.

Solitary Fibrous Tumor of the Floor of the Mouth: Case Report and Review of the Literature

Solitary fibrous tumor is an uncommon spindle cell neoplasm that is believed to be of mesenchymal origin. Rarely does it originate in the oral cavity, and only 1 case of this lesion in the floor of the mouth has been previously reported. We describe a new case of solitary fibrous tumor arising from the soft tissues of the floor of the mouth.

Solitary fibrous tumor of the retropharynx causing obstructive sleep apnea

Solitary fibrous tumors (SFTs) are rare, usually benign, spindle cell neoplasms that most often originate near mesothelium-lined surfaces of the pleural or peritoneal cavity. SFTs reported in the head and neck occur most commonly in the oral cavity, sinonasal tract, and orbit. We report a case of SFT of the retropharynx causing severe obstructive sleep apnea. The diagnostic and management strategies of SFTs are discussed.

Nasal solitary fibrous tumor arising from the anterior cranial fossa

The solitary fibrous tumor (SFT) is a mesenchymal, spindle cell neoplasm that was originally found in pleural tissue. Recently, however, numerous extrapleural sites have been discovered, including the nasal cavity. We present the 15th case of a nasal SFT, and the first such tumor to arise from the cribriform plate and extend into the anterior cranial fossa. In addition to highlighting the aggressive nature of this tumor, we review its clinical features and the diagnostic difficulties posed by SFT.

Solitary fibrous tumour of the oral cavity with histological features of aggressiveness

We operated on a 65-year-old woman and removed a solitary fibrous tumour from her oral mucosa. Microscopically we found marked atypia, abundant necrosis, increased number of mitotic figures (>4 in 10 high-power fields) and hypercellularity. The tumour cells were strongly stained for CD34. There has been no recurrence after 18 months.

Malignant solitary fibrous tumor of the tongue

Solitary fibrous tumor is a generally benign spindle-cell neoplasm that has been predominantly described in the visceral pleura and other serosal sites and is extremely rare in the head and neck area. We report the first known case of malignant solitary fibrous tumor of the tongue in a 57-year-old female patient who experienced rapid growth of a longstanding right anterior tongue mass, with associated dysphagia and dysarthria. Magnetic resonance imaging was suggestive of a low-flow vascular malformation not requiring preoperative embolization. The patient underwent partial peroral glossectomy for the excision of the tumor. Final pathology, however, was consistent with solitary fibrous tumor, characterized as malignant by histopathologic criteria, and the patient was returned for re-excision of the close surgical margins. The patient has experienced symptomatic improvement, and she remains free of recurrence 12 months later. All reports of solitary fibrous tumors of the oral cavity and 3 reports of the tongue tumors described in the literature to date represent benign lesions. To our knowledge, this is the first report of a malignant solitary fibrous tumor of the tongue. Presentation, differential diagnosis, criteria for malignancy, treatment, and possible prognostic implications of this rare entity are discussed.

Oral spindle cell neoplasms: a review of 307 cases

The infrequent exposure of pathologists to soft tissue spindle cell neoplasms coupled with overlapping histologic patterns can often make diagnosis challenging. We reviewed all nonodontogenic spindle cell neoplasms seen between 1982 and 2002 (86,162 total accessions). Diagnoses were reclassified according to current standards supplemented with immunohistochemistry. Of the 307 neoplasms reviewed (0.36% of total accessions), neural tumors were the most common benign entities, accounting for 21% of total cases. Kaposi's sarcoma was the most common malignancy, accounting for 67% of all cases. Diagnoses were revised for 57 cases. Schwannoma and neurofibroma were most commonly revised to palisaded encapsulated neuroma. There were 8 myofibromas and 1 inflammatory myofibroblastic tumor. There were no oral leiomyomas; that is, all 4 originally reported cases were reclassified as myofibroma, palisaded encapsulated neuroma, and solitary fibrous tumor. With the exception of Kaposi's sarcoma, oral soft tissue sarcomas were rare; most benign lesions were neural in origin. The relatively high prevalence of some tumors, such as myofibroma, likely reflects the use of immunohistochemistry in the diagnosis of spindle cell tumors.

Solitary fibrous tumor of the oral mucosa--morphological and immunohistochemical profile in the differential diagnosis with hemangiopericytoma

The objective was to investigate two cases of solitary fibrous tumor (SFT) of oral mucosa, emphasizing the differential diagnosis with one case of oral hemangiopericytoma (HPC), in terms of their morphological and immunohistochemical features. Solitary fibrous tumors showed cellularity and collagenization varying from area to area, focal perivascular hyalinization, scattered giant nuclei cells and abundant mast cells throughout the tumor. The hemangiopericytoma case exhibited thin-walled and dilated vessels lined with flat endothelial cells, identified by "staghorn appearance". Tumoral cells of solitary fibrous tumor exhibited immunohistochemical positivity for CD34, as well as endothelial cells. The hemangiopericytoma was positive only in endothelial cells. In solitary fibrous tumor, alpha-smooth muscle actin, h-caldesmon and laminin stained the wall vessels. In hemangiopericytoma, on the other hand, the wall vessels were positive only for laminin, which staining was also observed in perivascular tumoral cells. The morphological and immunohistochemical differences observed allowed us to infer these lesions constitute distinct entities.

Solitary fibrous tumor with malignant potential arising in sublingual gland

A rare case is described of a solitary fibrous tumor (SFT) with malignant potential arising in the sublingual gland. A 59-year-old man presented with a 4-month history of a slowly enlarging painless mass in the center of the floor of the mouth. The tumor was a well-demarcated, firm mass with a multicystic lesion. The tumor exhibited highly cellular areas of spindle cells with patternless architecture alternating with hypocellular areas. The tumor cells were positive for CD34 and bcl-2 as well as vimentin, and negative for epithelial, myogenic, neurogenic and histiocytic markers. The tumor cells formed multiple satellite nodules around dilated ducts in the multicystic lesion, indicating infiltrative growth. In addition, areas exhibiting higher cellularity with increased mitoses were noticed in the satellite nodules, although cellular atypia was not obvious. These findings led to a final diagnosis of SFT with malignant potential. There has been no recurrence or metastasis for 27 months after the surgery. Solitary fibrous tumor of the salivary gland must be differentiated from various spindle cell neoplasms including myogenic, peripheral nerve sheath, fibroblastic and fibro-histiocytic spindle cell neoplasms, hemangiopericytoma and myoepithelioma. In addition to characteristic morphological features, an immunohistochemical positivity for CD34 and bcl-2 may aid in the diagnosis of SFT.

Solitary fibrous tumour of the tongue: a case report with immunohistochemical studies

The solitary fibrous tumour (SFT), also known as a localized fibrous mesothelioma, is a neoplasm characterized by the proliferation of capillaries surrounded by masses of round or spindle-shaped cells. SFT has been discovered in many locations, however, it is extremely rare for SFT to be found in the intraoral region. We report here case of SFT arising from the tongue of a 75-year-old woman. To our knowledge, this is the second case reported of SFT originating from the tongue.

Solitary fibrous tumours of the lower gingiva: a case report

Solitary fibrous tumours (SFTs) are rare lesions in the oral cavity. Typically they arise in the pleura. We report a lesion occurring in the lower anterior gingiva. In histochemical examination, the spindle-shaped, neoplastic cells stained strongly for CD34 antigen and vimentin, but did not stain for desmin, smooth-muscle actin, muscle actin and S-100 protein. The expression of CD34 antigen and vimentin were useful for the differential diagnosis.

Solitary fibrous tumor of the parotid gland: a case report

The solitary fibrous tumor is traditionally associated with a mesothelial-lined surface. However, any organ with mesenchymal tissue has the potential for developing this tumor; therefore, it has been described in organs not associated with serosal surfaces. We report a case of solitary fibrous tumor of the parotid gland. Microscopically, the tumor showed a patternless arrangement of spindle cells in a fibrotic background and prominent vascular structures of varying size. Tumor cells showed a strong immunoreactivity for CD34 and bcl-2 antigens, but the tissue was negative for antibodies directed against actins, S-100 protein, and cytokeratins. One year after excision, the patient was alive and without evidence of disease.

Solitary fibrous tumour of the mouth: report of two cases involving the tongue and cheek

We describe two additional cases of solitary fibrous tumour (SFT) affecting the mouth. SFT is very uncommon in the oral cavity and we found only 14 cases reported in the literature. Our two cases were well circumscribed, slow growing tumours that, after surgical removal, did not recur. Case 1 was a 3 cm nodule on the right cheek. Hypo and hypercellular adjacent areas were mainly patternless, and the stroma was formed by thin collagen fibrils. Case 2 was a 4.8 cm mass in the anterior portion of the tongue. Microscopically it was formed by spindle cells embedded in a vascularized sclerotic collagen matrix. Some areas were hypercellular with scarce collagen fibrils. The immunohistochemical findings were similar in both cases, with strong immunoreactivity for vimentin, CD34, bcl-2, focal positivity for Ki-67 and negativity for other immunomarkers. Based on these clinical, microscopical and immunohistochemical features the final diagnosis of these two cases was SFT. Diagnosis of SFT is difficult and, although uncommon, it should be considered in the differential diagnosis of oral soft tissue tumours.

Advanced diagnostic methods in oral and maxillofacial pathology. Part II: immunohistochemical and immunofluorescent methods

The practice of pathology is currently undergoing significant change, in large part due to advances in the analysis of DNA, RNA, and proteins in tissues. These advances have permitted improved biologic insights into many developmental, inflammatory, metabolic, infectious, and neoplastic diseases. Moreover, molecular analysis has also led to improvements in the accuracy of disease diagnosis and classification. It is likely that, in the future, these methods will increasingly enter into the day-to-day diagnosis and management of patients. The pathologist will continue to play a fundamental role in diagnosis and will likely be in a pivotal position to guide the implementation and interpretation of these tests as they move from the research laboratory into diagnostic pathology. The purpose of this 2-part series is to provide an overview of the principles and applications of current molecular biologic and immunologic tests. In Part I, the biologic fundamentals of DNA, RNA, and proteins and methods that are currently available or likely to become available to the pathologist in the next several years for their isolation and analysis in tissue biopsies were discussed. In Part II, advances in immunohistochemistry and immunofluorescence methods and their application to modern diagnostic pathology are reviewed.

Solitary fibrous tumor in the mental region

Solitary fibrous tumor (SFT) is a rare, benign, soft tissue tumor that most commonly occurs in the pleura; however, it has recently been described in other sites of the body. To date, eight examples of oral SFT have been reported. This paper is a description of the first case of an SFT occurring as a soft tissue tumor in the mental region. Histologically, the tumor was composed predominantly of rather uniform spindle-shaped fibroblastic cells arranged in vague fascicles or in a haphazard fashion, intermingled with abundant collagen fibers. Immunohistochemically, the tumor cells were positive for CD34 and vimentin, and weakly positive for muscle actin and alpha-smooth muscle actin. The diagnosis of SFT may be difficult as this tumor shares a number of histological features with other soft tissue tumors. Awareness of its occurrence in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided.

Locally aggressive solitary fibrous tumor in the infraorbital region: a case report and review of the literature

We describe a case of a soft tissue neoplasm in the infraorbital region of a 31-year-old African-American man that met histologic and immunohistochemical criteria for solitary fibrous tumor. This uncommon spindle cell neoplasm was first described in the pleura, but it has since been reported in many other soft tissue locations. The lesion was locally aggressive and successfully treated by local excision. Solitary fibrous tumor can be locally destructive and can occur in a wide variety of tissues or organs; this is the seventh published case of solitary fibrous tumor in the orofacial region.

Solitary fibrous tumor of the oral soft tissues: a clinicopathologic and immunohistochemical study of 16 cases

We describe the clinicopathologic and immunohistochemical features of 16 solitary fibrous tumors (SFTs) originating within the oral soft tissues. There were 10 women and six men with a mean age at diagnosis of 56 years. In all cases the tumors were slow-growing, asymptomatic, submucosal growths of variable size and duration. The buccal mucosa was involved in 12 cases, and the tongue and lower lip were affected in two cases, respectively. Thirteen tumors developed on the left side of the mouth. Follow-up information was available in 10 cases and averaged 44.7 months, with no evidence of recurrence or metastasis. All 16 tumors were well circumscribed and demonstrated histologic features that were invariably benign. In all cases they were composed of an admixture of alternating hypercellular and hypocellular, collagenous zones; haphazardly arranged, cytologically bland spindle and ovoid cells that in areas were intimately intermixed with collagen; a prominent vasculature; and perivascular hyalinization. Immunohistochemically, the tumors were consistently positive for CD34, bcl-2, factor XIIIa, and vimentin, whereas 75% of the tumors were reactive for CD99. To further define the clinicopathologic profile of intraoral SFT, we include a review of the previously reported cases. We also include a comparison and brief review of the clinicopathologic and immunohistochemical features of other spindle cell tumors of the oral cavity, from which SFTs must be differentiated.

Primary intraoral leiomyosarcoma of the tongue: an immunohistochemical study and review of the literature

Leiomyosarcoma is a relatively uncommon mesenchymal tumor that exhibits smooth-muscle differentiation. We report a new case of leiomyosarcoma involving the tongue of a 67-year-old male. Histologically, the tumor was composed of variably oriented fascicles of spindle-shaped cells with 'cigar-shaped' nuclei and eosinophilic cytoplasm, containing occasional PAS-positive granules. Atypical mitotic figures and necrotic foci were frequently detected. Consistent desmin, alpha-smooth muscle-specific and sarcomeric actin, and vimentin immunoreactivity was demonstrated in the tumor cells, whereas cytokeratins, CD 30, CD 31, CD 34, CD 45, CD 68, EMA, GFAP, HMB 45 and S-100 protein were negative. The patient underwent wide surgical excision of the tumor and is alive and disease-free at a 5-year follow-up. This report emphasizes the difficulties in the differential diagnosis of these uncommon tumors in an intra-oral location.

Giant cell angiofibroma of the oral cavity: report of a new location for a rare tumor

Giant cell angiofibroma is a rare, soft tissue tumor that was first described in the orbit. Since then, several case reports have described this tumor in a number of extra-orbital sites, suggesting a wider anatomic distribution than is generally recognized. The tumor typically acts in a benign fashion with only rare local recurrences but no tendency to metastatic disease. Here, we report the first case of a giant cell angiofibroma in the oral cavity. The tumor presented as a soft tissue nodule on the buccal mucosa of a 60-year-old man. The histologic differential diagnosis included a number of other uncommon soft tissue neoplasms, including giant cell fibroblastoma, solitary fibrous tumor, and pleomorphic lipoma. The histologic and immunohistochemical features of this tumor and differentiation from other histologically similar soft tissue neoplasms are briefly discussed.