Leiomyomatous hamartoma of the incisive papilla

A case of unusual hamartoma in a six-year-old otherwise healthy Brazilian girl is reported, with emphasis on histological and immunohistochemical features. A mass observed in the incisive papilla was detected whose appearance was similar to congenital epulis or fibroma. Histological findings showed interlacing fascicles of large spindle cells resembling smooth muscle cells. Immunohistochemical staining for desmin and for smooth-muscle actin was positive. The histological diagnosis was leiomyomatous hamartoma, based on clinical and microscopic observations.     

Immunoprofile of a carcinosarcoma of the submandibular gland

Carcinosarcomas are a very rare group of true malignant tumors of the salivary gland. As the name indicates, the tumor is composed of an epithelial and a mesenchymal component, both malignant. We report a case of carcinosarcoma of the submandibular gland in an 86-year-old woman. The epithelial component showed a squamous carcinoma phenotype, whereas the mesenchymal component was morphologically similar to a fibrosarcoma. The epithelial component was strongly positive for CK13, CK14, and AE1/AE, and groups of positive cells were seen for CK19 and vimentin. The whole mesenchymal component was positive for vimentin, negative for cytokeratins, and focal cells were positive for smooth- muscle actin. Both components were strongly positive for P53 and Cyclin D1, and focally positive for MDM2. Rare multinucleated giant cells showed expression of CD68, and focal dendritical cells on carcinomatous nests were positive for S-100. The CK7, CK8, Factor XIIIa, c-erbB-2, P16, CDK-4, Rb1, and E2F-1 were not detected in these 2 groups of malignant cell populations.     

Angiomyolipoma of the upper lip: case report and review of the literature

Angiomyolipoma (AML) is a hamartomatous growth that usually affects the kidney. One third of patients with AML present with manifestations of tuberous sclerosis. Oral AML is rare with only 6 cases reported in the English-language literature. In the present case, AML was located in the upper lip of a 43 year-old woman. Clinically, it presented as a firm nodule, well circumscribed and measuring 1 x 2 cm. It was surgically excised. Histopathological analysis showed a lesion composed of an admixture of smooth muscle cells, blood vessels, and adipose tissue. The immunohistochemical study revealed positivity for vimentin, smooth muscle actin, pan specific muscle actin and desmin. CD68, CD34 and mast cell antibodies showed focal immunoreactivity. S100 protein, Ki-67, and HMB-45 were negative. Based on these histological and immunohistochemical features the diagnosis was of oral AML. No recurrence was observed after 2 years of follow-up.     

Fibrosarcoma of the mandible: case report of a unique radiographic appearance

Fibrosarcoma is a rare malignant fibroblastic neoplasm that only rarely affects the oral cavity. Here, we describe a rare case of fibrosarcoma affecting the mandible of a 10-year-old girl. Orthopantomography showed a well-defined radiolucency with a cortical rim typical of a benign lesion. However, occlusal radiographs showed Codman’s triangle, indicating the malignant nature of the lesion. Computed tomography showed a radiolucent lesion involving the buccal aspect of the mandible, and histopathological examination confirmed the diagnosis. The patient underwent surgical resection of the tumor and is currently undergoing regular follow-up examinations.     

Inflammatory myofibroblastic tumor of the alveolar mucosa of the mandible

Inflammatory myofibroblastic tumor is a rare lesion composed of myofibroblastic spindle cells accompanied by inflammatory infiltrate. The objective of this paper is to report an uncommon case of inflammatory myofibroblastic tumor located in the alveolar mucosa of the mandible. A 33-year-old male presented an asymptomatic tumoral lesion, firm, pedunculated, pink-colored, covered by smooth mucosa, with focal ulceration, measuring 30x20x20 mm, located in the left posterior alveolar mucosa. Clinical diagnosis was soft tissue tumor. An excisional biopsy was made. Microscopic examination showed compact fascicular spindle cells proliferation with a diffuse inflammatory infiltrate of plasma cells, lymphocytes, and eosinophils. Large ganglion-like cells were observed. The lesional cells were immunopos-itive to vimentin, a-smooth muscle actin, muscle specific actin, and CD68. Negative immunostain was observed to S-100, Bcl-2, Ki-67, desmin, CD34, and cytokeratin. A diagnosis of inflammatory myofibroblastic tumor was performed. After 28 months of follow-up there was no recurrence. Although no evidence of oral inflammatory myofibroblastic tumor recurrence or malignant transformation has been reported, it has been observed that in inflammatory myofibroblastic tumor of other regions a prolonged follow-up is necessary after surgical excision.     

Ameloblastic fibrosarcoma of the right mandible: immunohistochemical and electron microscopical investigations on one case, and a review of the literature

A case of a 7-year-old girl with ameloblastic fibrosarcoma of the right mandible is described. Immunohistochemical techniques (detection of intermediate filaments, tissue polypeptide antigen, lactoferrin, lysozyme, Factor VIII-related protein, S-100 protein, carcinoembryonic antigen, alpha-foeto-protein, "lectin-receptors") and electron microscopy were applied. The epithelial part of the tumor, which was positive for keratin, showed distinct tonofilaments in electron microscopy. In contrast, the mesenchymal part was vimentin positive. The cells displayed the ultrastructural features of fibroblasts. The observations are compared with those reported in the literature.     

Ameloblastic fibrosarcoma of the right mandible: immunohistochemical and electron microscopical investigations on one case, and a review of the literature

A case of a 7-year-old girl with ameloblastic fibrosarcoma of the right mandible is described. Immunohistochemical techniques (detection of intermediate filaments, tissue polypeptide antigen, lactoferrin, lysozyme, Factor VIII-related protein, S-100 protein, carcinoembryonic antigen, alpha-foeto-protein, "lectin-receptors") and electron microscopy were applied. The epithelial part of the tumor, which was positive for keratin, showed distinct tonofilaments in electron microscopy. In contrast, the mesenchymal part was vimentin positive. The cells displayed the ultrastructural features of fibroblasts. The observations are compared with those reported in the literature.     

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.     

Desmoplastic fibroma of the mandible: case report.

This report describes the case of a 2-year-old girl with desmoplastic fibroma of the mandible, with swelling in the region of the mandibular angle which had been wrongly diagnosed several times. A biopsy was interpreted as showing a low-grade fibrosarcoma. The patient then received treatment with cytotoxic drugs, and later a mandibular hemi-resection was performed. The postoperative diagnosis was Jaffé's desmoplastic fibroma (non-osteogenic). The age of the patient, the rapid development of the tumour and the accompanying pain suggested a sarcoma, and the first pathological examination seemed to provide confirmation. The post-operative course was very favorable, and the patient is considered to clinically cured, after one year.     

Misdiagnosed fibrosarcoma of the mandible mimicking temporomandibular disorder: a rare condition

The jawbones can be sites of various neoplastic conditions. Given the variety of processes affecting this particular anatomical area, formulation of a precise diagnosis can be challenging to clinicians. Limited jaw movement, pain, and facial asymmetry are common signs among patients, especially those with temporomandibular disorder (TMD). This paper reports a case of primary fibrosarcoma affecting the mandible and surrounding structures in a 14-year-old girl presenting signs and symptoms similar to TMD. Her condition was misdiagnosed, and she was treated for TMD over an extended period before the correct diagnosis was made for fibrosarcoma. The patient underwent surgical resection with postsurgical radiotherapy and chemotherapy and now is being followed up. Although malignant lesions are rare in the temporomandibular joint (TMJ) region, dentists are advised to be aware of the condition and to keep in mind that patients who are admitting for TMD can also possibly be affected from neoplasms. Hence, those patients have to be examined meticulously to avoid misdiagnosis and mistreatment.     

Primary intraosseous fibrosarcoma of jaw

This paper reports one case of primary fibrosarcoma affecting the mandible in a 41-year-old woman. Microscopically, the tumor was cellularized with an intense mitotic activity, and areas of necrosis and hemorrhage, and the cells showed immunoreactivity only for vimentin, establishing the diagnosis of primary intraosseous fibrosarcoma. The patient underwent tumor surgical resection, supraomohyoid neck dissection and mandible reconstruction with fibula flap and titanium bar. She also received post-surgical radiotherapy and is in follow up for 36 months without signs of recurrence or metastases.     

Leiomyomatous hamartoma presenting as a congenital epulis

An otherwise-healthy 11-month-old white girl presented with a polyp-like lesion on the anteromedial part of the maxillary alveolar ridge. It looked like a congenital epulis, but histological examination showed fascicles of smooth muscle cells dispersed in collagenous stroma with a few peripheral nerve bundles that were intermingled with smooth muscle fibres. The muscle cells stained strongly for desmin and alpha-smooth-muscle actin. However, S-100 was found only in peripheral nerve bundles. It was therefore a leiomyomatous hamartoma.     

Nodular fasciitis in the zygomatic area. Case report and review of the literature

The authors report a clinical case of nodular fasciitis in the zygomatic area. Although this tumor-like proliferation occurs very rarely in the maxillofacial region, careful diagnosis based on histologic examination must distinguish it from neoplastic lesions such as fibrosarcoma with which the disorder shares certain histologic features. The case is compared with others described in the literature. In June 1996 a 12-year-old girl presented at our unit with swelling of the zygomatic region and positive history for trauma to the area. Palpation of the soft tissues detected a nodular formation about 1.5 cm in diameter. Echography and magnetic resonance imaging confirmed the presence of a nodular proliferation above the bone surface. The nodule was surgically removed by skin excision, and histologic examination of the specimen confirmed the diagnosis of nodular fascitis. The etiology of the lesion was thought to be a reaction to trauma, in agreement with data reported in the literature. Nodular fasciitis is a benign, non-recurrent lesion; however, its rapid growth and the histologic features it shares with more aggressive tumors such as fibrosarcoma call for careful differential diagnosis. As in our case, a history of previous trauma to the involved area can aid in establishing a correct diagnosis.     

Solitary fibrous tumour of the oral cavity: clinicopathological and immunohistochemical characterization of three cases

Solitary fibrous tumour (SFT) is an uncommon mesenchymal neoplasm rarely located in the oral cavity. To characterize further oral SFT, we describe three new cases. Each tumour originated in the buccal mucosa of a middle-aged/elderly patient. Histological examination showed well-circumscribed tumours with densely cellular areas alternating with hypocellular areas in a variedly collagenous, vascular stroma. Mast cells were abundant. The spindle-shaped, neoplastic cells immunostained strongly for CD34 antigen and vimentin and weakly for bcl-2, but not for epithelial cell markers, alpha-smooth muscle actin, or neurofilament or S-100 proteins. Compatible with the virtual absence of mitoses and of marked nuclear atypia, the overall frequency of proliferating cells expressing Ki-67 was low. The expression of CD34 was useful in the differential diagnosis. The consistent location in the cheek and expansion of one tumour after local trauma does not preclude a traumatic element in the development of oral SFT.     

Benign fibrous histiocytoma in the condylar process of the mandible: Case report

A 48-year-old man was referred for investigation of an asymptomatic radiolucent lesion in the mandible. The margin was partly irregular, and there was no peripheral sclerosis. The tumour was composed of histiocytic cells, spindle cells, and fibrous tissue. Immunohistochemical analysis showed that the tumour cells stained for CD68 and vimentin, and not for cytokeratin, smooth muscle actin, S-100 protein, or CD34. The tumour was therefore diagnosed as a benign fibrous histiocytoma.     

Extranodal follicular dendritic cell sarcoma of the palate

Follicular dendritic cell tumors are uncommon and usually occur in lymph nodes. We report the case of a follicular dendritic cell tumor that occurred in the palate of a 14-year-old boy and manifested itself as a nodular mass. Histologically, the neoplasm consisted of spindle-shaped or oval-shaped cells with eosinophilic cytoplasms and nuclei with delicate, dispersed chromatin. The lesional cells were principally arranged in diffuse, fascicular patterns with vaguely whorled or storiform areas. Focal multinucleate tumor giant cells and lymphocytes were observed throughout the neoplasm. Immunohistochemically, tumor cells were positive for the follicular dendritic cell markers CD21, CD35, and CD23 and for S-100 protein, CD68, and muscle-specific actin. Tumor cells were negative for LCA, CD20, EMA, CK (AE1/AE3), HMB45, and CD34. Lymphocytes were positive for LCA and CD45RO. Although follicular dendritic cell sarcoma is a very uncommon tumor, it should be included in the differential diagnosis of tumors in this location.     

Unexpected diagnosis of an intramuscular myxoma arising from the masseter muscle

Intramuscular myxomas are myxoid neoplasms that mainly affect the muscles of the thigh, upper arm, and gluteus. In the head and neck region they are rare, and we know of only two reported cases in the masseter muscle. We think that this is the third. A 60-year-old woman presented with a painless nodule on the right side of her face. Magnetic resonance imaging showed a well-defined mass restricted to the muscle, with no infiltration into adjacent structures. Microscopic analysis confirmed the gross examination, and showed a tumour with copious myxoid stroma, scattered spindle to stellate cells, and an absence of atypia, which did not stain for CD34, S100, or smooth-muscle actin. A final diagnosis of intramuscular myxoma was made. Despite its rarity, it is important to consider this neoplasm in the differential diagnosis of tumours with a gelatinous-like appearance that involve masticatory muscles of the head and neck.     

CD34 expressing ameloblastic fibrosarcoma arising in the maxilla: a new finding

Ameloblastic fibrosarcoma (AFS) is a rare malignant tumor of the jaw. The malignant mesenchymal component of AFS has been described as 'fibroblast-like', although little is known about the immunophenotype, except for vimentin expression. Here, we present a case of AFS in a 62-year-old woman. The mesenchymal component displayed the features of either dermatofibrosarcoma protuberans or fibrosarcoma, and was positive for CD34. This is the first reported case of CD34 expressing AFS in the maxilla.     

Central giant cell granulomas of the jaws: phenotype and proliferation-associated markers

Central giant cell granulomas (CGCGs) are jaw tumors of unknown origin that often exhibit an aggressive, though unpredictable, clinical course. The purpose of this study was to determine the immunoprofile of the mononuclear cells that seem to be responsible for the biologic behavior of these tumors. Numbers of cells in cell cycle were also determined and compared in clinically aggressive and non-aggressive CGCGs. Sixteen aggressive and 12 non-aggressive CGCGs were immunohistochemically stained with antibodies to CD34, CD6S. factor XHIa, ct-smooth muscle actin. prolyl 4-hydroxylase, Ki-67. and p53 protein. Cell populations and numbers of cells in cell cycle were determined through microscopic quantitative assessment. CD34-positive ceils were limited to support vessels. CD68-positive mononuclear cells constituted a small population of cells in ail tumors. With two exceptions, factor XIIIa-positive cells were rarely seen. Alpha-smooth muscle actin staining was present in approximately half the tumors, and occasionally large numbers of positive cells were seen. Most mononuclear cells were positive for fibroblast-associated antigen. No phenotypic differences were detected between aggressive and non-aggressive tumors. P53 protein did not appear to be overexpressed in CGCGs. Ki-67 staining showed that only mononuclear cells were in cell cycle, and that there were no differences between aggressive and non-aggressive tumors. We conclude that CGCGs are primarily fibroblastic (and myofibroblastic) tumors in which macrophages appear to play a secondary role. Tumor cells show no differentiation toward endothelial cells or macrophage-related dendrocytes (factor XIIIa). Cellular phenotypes and numbers of cells in cell cycle are similar in both aggressive and non-aggressive tumors.     

Immunocytochemical study of giant cell fibroma

Giant cell fibroma (GCF) is a non-neoplastic lesion of the oral mucosa. The origin of stellate and multinucleate cells of GCF is not well known. The purpose of the present article was to investigate the immunoreactivity of these cells for leukocyte common antigen, vimentin, tryptase, HLA-DR, alpha-smooth muscle actin, CD68, and S-100. The results showed positive staining only for vimentin. This suggests that the stellate and multinucleate cells of GCF have a fibroblast phenotype.