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

Solitary fibrous tumor of the floor of the mouth

BACKGROUND

A solitary fibrous tumor (SFT) of the oral cavity is an extremely rare entity. Its diagnosis is complicated because of its diverse morphology and similarity to other mesenchymal diseases.

CASE REPORT

A rare case of SFT involving floor of the mouth is presented. The tumor was well circumscribed and almost spherical, measuring approximately 3 cm in diameter. Patient was submitted to biopsy and histopathologic examination showed a tumor composed of spindle to epithelioid cells showing pale to eosinophilic cytoplasm, oval or elongated nuclei with inconspicuous nucleoli. Tumor cells showed strong positivity for CD34, vimentin and Bcl-2. SFTs may present as a diagnostic challenge. The patient was followed for 8 years without recurrences.

RESULTS

SFT is an uncommon disease in maxillofacial region; however it should be considered in the differential diagnosis of spindle cell neoplasms with oral manifestation. Only a few cases have been reported in the floor of mouth. We describe a new case of SFT arising at this location. Key words:Solitary fibrous tumors, mouth floor, oral diagnosis.

Solitary fibrous tumour of the cheek: An unusual presentation of a rare soft tissue tumour

This case report discusses the unusual presentation and ultrasound features of a solitary fibrous tumour of the face. Solitary fibrous tumour is an uncommon form of soft tissue tumour which, although seen predominantly within the lung pleura, can occur throughout the body in sites such as the peritoneum, mediastinum and head and neck. Ultrasound is an excellent imaging modality in the assessment of soft tissue masses in the head and neck. The ultrasound features demonstrated by this example of solitary fibrous tumour are reviewed. This report also highlights that ultrasound alone is ultimately limited in reaching a definitive diagnosis. The roles of other investigations such as ultrasound-guided biopsy and cross-sectional imaging are discussed.

[Solitary fibrous tumour of the smooth palate]

The solid fibrous solitary tumour of the oral cavity is an extremely rare entity. It is also of complicated diagnosis because of its extensive morphologic diversity (especially when there is a small amount of biopsied tissue) and because of its similarity to many mesenchymal injuries, mostly with hemangiopericytoma. The prognosis is reserved because of the few cases reported, mainly depending on tumour location and size.

[Solitary fibrous tumour of the pleura: five cases]

Solitary fibrous tumours are unusual mesenchymatous tumours, most often found on the pleura. The authors report five cases hospitalised between 1998 and 2003. With the greatest occurrence in the fifth decade, they are often accidentally found but sometimes associated with a paraneoplastic syndrome such as refractory hypoglycaemia. The diagnosis is based on computed tomography and complete surgical resection is the best treatment. Adjuvant therapy is proposed for the histologically aggressive forms. Because of the possibility of local or distant recurrence and malignant transformation, long-term monitoring is strongly recommended.

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 oral cavity: the need for an extensive sampling for a correct diagnosis

BACKGROUND

Solitary fibrous tumor (SFT) is an uncommon but well-characterized soft tissue tumor that was first described as a pleural lesion and now is considered ubiquitous, having been detected at many extra-pleural sites (abdominal cavity, orbit, upper respiratory tract, and oral cavity). Histologically, SFT may show wide morphological variability of both its cellular and stromal components, which may lead to incorrect diagnosis especially when dealing with small incisional biopsies.

MATERIALS

We report on the clinical, morphological and immunohistochemical features of eight SFT occurring in the oral cavity.

RESULTS

Microscopically all eight tumors showed widely variable morphological features in terms of cellular density and stromal architecture, thus simulating benign fibrous histiocytoma, schwannoma, hemangiopericytoma or low-grade sarcoma in distinct areas of the same lesion. Among these eight cases, five had been diagnosed as SFT, two as benign fibrous histiocytoma and one as low-grade sarcoma.

CONCLUSIONS

In consideration of the heterogeneous morphological appearance of SFT, inaccurate sampling of the mass may lead to misdiagnosis and inappropriate treatment. Therefore, an accurate histological examination of multiple tissue sections is advised, along with the use of appropriate immunostains.