Desmoplastic fibroma of the jaw: a case report and review of literature.

Desmoplastic fibroma is a benign intraosseous neoplasm that is recognized as the intraosseous counterpart of soft tissue fibromatosis in both gnathic and extragnathic sites. It has a propensity for locally aggressive behavior and local recurrence. In the present report, we define the clinicopathological and radiographic features of a desmoplastic fibroma of the mandible in an 8-year-old white boy who initially presented with a 2-month history of a rapidly expanding, painless mass along the right inferior border of his mandible. A critical and comprehensive review of the English language literature is also provided.

Collagenous fibroma ( desmoplastic fibroblastoma ) of alveolar bone: a case report

O fibroma colagenoso (fibroma desmoplásico) é um tumor de tecido mole raro de origem fibroblástica. Na mucosa oral apenas dois casos foram descritos pela literatura. Nós descrevemos o caso de uma mulher de 42 anos de idade, cuja queixa era uma lesão indolor, de crescimento lento sob sua prótese total superior. Os achados histológicos da lesão incluíram fibroblastos escassos, estrelados ou fusiformes, dispersos em um estroma rico em colágeno. As células lesionais foram positivas para vimentina, mas rara marcação foi observada para actina músculo liso e fator XIIIa. A excisão cirúrgica total foi realizada e a recidiva da lesão não é esperada.

[Desmoplastic fibroma of the rib: two case reports]. / Le fibrome desmoplastique de la côte: à propos de deux observations.

Desmoplastic fibroma is a very rare primary tumor of bone, closely related to aggressive fibromatosis of soft tissue. Although considered a benign lesion, it can be very aggressive locally and has a high rate of local recurrence after incomplete surgical excision. Radiologically, the lesion shows no distinctive features, often simulating osteosarcoma, fibrous dysplasia, or fibrosarcoma. Rib involvement by desmoplastic fibroma is extremely rare. We present two cases of desmoplastic fibroma involving this unusual location with lytic costal lesion and chest wall extension. Histological examination after surgical resection revealed that the tumor consisted of spindle cells with small, elongated nuclei in a background of numerous collagen fibers and infiltrating lamellar bone. There was no evidence of nuclear atypia, mitotic activity, or necrosis. We also discuss histological differential diagnosis as well as clinical features and the radiological and pathologic findings of this rare disease. Recognition of this entity is important to ensure proper surgical treatment.

Desmoplastic fibroblastoma: a light and ultrastructural description of two cases.

The authors report 2 cases of collagenous fibroma in which ultrastructural analysis revealed the presence of fibronexus junctions, markers of myofibroblastic differentiation, never described in this rare lesion before. The tumors occurred in the trapezius muscle and in the right arms of a 41 -year-old and a 25-year-old man. They were both intramuscular and showed sharp edges. Grossly, the excised masses were whitish and firm. Microscopically, they were both composed of stellate or spindle-shaped cells separated by a collagenous hypovascular and focally myxoid stroma. Mitotic figures and necrotic areas were not identified. Immunohistochemistry showed positivity for vimentin and focal positivity for smooth and human muscle actin, and flow cytometry showed the tumoral cells to be diploid.

Selected case from the Arkadi M. Rywlin International Pathology Slide Seminar: desmoplastic fibroblastoma (collagenous fibroma).

Desmoplastic fibroblastoma (collagenous fibroma) is a rare and recently described benign soft tissue tumor. It is more common in men, median age is 50 years, the history is usually long, and the usual size is around 3 cm. Most lesions are subcutaneous but approximately 25% involve skeletal muscle. Histologically, they are sparsely cellular with stellate and spindle-shaped fibroblasts-myofibroblasts that are separated by a collagenous or myxocollagenous matrix. Mitoses are minimal or absent. Tumor cells are focally positive for muscle-specific and alpha smooth muscle actins, and rarely, for keratins. The S-100 is usually negative but a very few cases have been positive. It can be confused with one of the fibromatoses, myxomas of various kinds and neural tumors. It neither recurs nor metastasizes.

Collagenous fibroma (desmoplastic fibroblastoma): report of four cases and review of the literature.

BACKGROUND: Collagenous fibroma (desmoplastic fibroblastoma) is poorly recognized and may be mistaken for other benign or even malignant spindle-cell tumors of soft tissue because of the small number of reported cases. DESIGN: Collagenous fibromas resected from four adult women were studied histologically and immunohistochemically. RESULTS: The tumors were well-circumscribed firm masses, measuring from 1.0 to 13.8 cm (mean, 5.5 cm) across the greatest diameter, located in the subcutaneous or deep soft tissue of the shoulder, thigh, back, and neck. Each of the tumors was characterized by a paucicellular lesion with spindle- and stellate-shaped fibroblastic cells embedded in a hypovascular, densely fibrous stroma. Mitotic figures and necrosis were not identified. One tumor contained dystrophic calcification and metaplastic bone, and another included small foci of floretlike multinucleated giant cells. Although appearing well demarcated on gross examination, one tumor focally infiltrated the surrounding skeletal muscle and adipose tissue. On immunohistochemical examination, all of the tumors were diffusely positive for vimentin. One tumor showed focal staining for alpha-smooth muscle actin, and another was partially positive for desmin, a staining profile that is typical of myofibroblasts. No tumor recurred during the follow-up periods of 67 to 108 months (mean, 93 months). CONCLUSION: Collagenous fibroma may be a distinctive fibrous soft-tissue tumor with benign biological behavior.

[Desmoplastic fibroblastoma]. / Dezmoplastický fibroblastom.

We report a light microscopic and ultrastructural appearance, and immunohistochemical profile of two benign tumours of soft tissue recently designated as desmoplastic fibroblastoma (collagenous fibroma). The tumours were located in the foot and well demarcated. Microscopically, they were composed of stellate--or spindle--shaped cells embedded in a hypovascular fibrous of fibromyxoid stroma. Immunohistochemical examination showed that tumours were diffusely positive for vimentin and focaly positive for smooth muscle actin and muscle specific actin. Ultrastructurally, the neoplastic cells had features of fibroblasts and myofibroblasts.

Unique desmoplastic cerebral tumor in a patient with complex partial seizures.

Primary brain tumors with prominent desmoplasia include the gliofibroma, desmoplastic infantile ganglioglioma (DIG), pleomorphic xanthoastrocytoma (PXA), and desmoplastic cerebral astrocytoma. In the present report, we describe unusual pathological appearances in two successive resections of a left temporal tumor in a patient with complex partial seizures. Both tumors showed focal astroglial and very prominent neuronal differentiation. In the first resection at age 11 years, the tumor showed only focal desmoplastic areas and prominent neuronal differentiation with bizarre atypical giant cells. In the second resection at age 14 years, the morphology was dramatically different. Now the tumor showed marked desmoplasia with tumor cells coexpressing neuronal and glial markers. Electron microscopy showed prominent neuronal differentiation in both resections and presence of basal lamina around tumor cells. Our case represents a unique example of an extraordinary degree of neuronal differentiation in a desmoplastic cerebral tumor. While cellular pleomorphism in a desmoplastic tumor traditionally suggests the diagnosis of PXA, we wish to underscore that many cells exhibiting marked cytologic atypia may in fact be of neuronal rather than of glial origin as in our case.