Desmoid tumor of bone with enchondromatous nodules, mistaken for chondrosarcoma

Desmoid tumor of bone, also termed desmoplastic fibroma or aggressive fibromatosis, is a rare, locally aggressive fibroblastic tumor. We present a 16-year-old male with a huge desmoid tumor involving the iliac wing. It was associated with enchondromatous nodules mimicking malignancy. The tumor in this patient was mistaken for chondrosarcoma and hemipelvectomy was performed. To our knowledge, such a case has not previously been documented fully in the English literature. The radiographic and pathologic findings and a possible mechanism of enchondromatous nodule formation in fibrous bone tumors are discussed.

Low-grade fibrosarcoma of the proximal humerus

We present the clinical, radiographical and pathological features of low-grade fibrosarcoma of the left proximal humerus in a 23-year-old man in whom it was necessary to distinguish the tumor from desmoplastic fibroma, malignant fibrous histiocytoma and intramedullary well-differentiated osteosarcoma. The patient presented with a 10-day history of pain in his left upper arm sustained when trying to break his fall with his left hand when slipping in the street. Plain radiography revealed an expanding multilobular osteolytic lesion from the proximal metaphysis to the diaphysis of his left humerus, accompanied by a pathological fracture at the distal portion of the lesion. Open biopsy of the lesion was performed twice; however, a conclusive diagnosis could not be obtained. The patient underwent wide excision and prosthetic replacement of the left proximal humerus. Histologically, the resected tumor was composed of both cellular areas and hypocellular areas. Cellular areas revealed a proliferation of bundles of uniform fibroblastic spindle-shaped cells with minimal cellular atypia, mixed with abundant intercellular collagenization. Mitotic figures were occasionally seen. Hypocellular areas showed myxoid features with loose bundles of collagen fibers. The patient demonstrates no evidence of disease 42 months after surgery. It is important to detect the scant atypical cells for the differential diagnosis of low-grade fibrosarcoma and desmoplastic fibroma of bone.

CT and MR imaging of desmoplastic fibroblastoma

Desmoplastic fibroblastoma (collagenous fibroma) developing as a slowly enlarging lower abdominal mass is described. The lesion had inhomogeneous low signal intensity (SI) on T1-weighted images, and mixed SI as low SI within high SI on T2-weighted images. On post-contrast T1-weighted images, the mass showed inhomogeneous enhancement. Histologically, the areas showing low SI on both post-contrast T1- and T2-weighted images consisted of dense collagenous components and reduced cellularity compared with the areas showing high SI on them.

Desmoplastic fibroma in the thoracic spine: an unusual localization of a rare primary bone tumor

A case of an intraspinal growing desmoplastic fibroma of the thoracic spine (T9-T11) is reported. Desmoplastic fibroma is a rare tumor of connective tissue that shows a locally infiltrative and destructive growth. An affection of the thoracic spine is an extremely rare manifestation. Preoperative CT documents the extent of osseous destruction and tumor associated cortical erosion. In central tumor areas an inhomogeneous, intermediate to low signal is demonstrated by MRI using T1- and T2-weighted spin-echo and turbo-spin-echo sequences. Contrast-enhanced MRI shows marked enhancement in peripheral areas depicting the extraosseous and intramedullary extension.

[Desmoplastic fibroma of the fibula. A difficult clinical, radiological and histological diagnosis]

Desmoplastic fibroma of bone is a rare benign tumor that is made up of wavy fibroblasts and abundant collagenous tissue. The case of a 18-year-old patient is presented with a two months history of weightbearing pain in the left knee. Neither native x-ray, CT nor MRI could detect the kind of tumor. The histological findings lead finally to the diagnosis of a desmoplastic fibroma. Wide resection prevented recurrence of the tumor for 8 1/2 years until now. Considering the semi-malignant character of the desmoplastic fibroma and the recurrence rate marginal or wide resection for the primary treatment is recommended. The superior imaging quality of MRI facilitates preoperative planning.

Primary musculoskeletal tumors of fibrous origin

Tumors of fibrous origin include fibrous dysplasia (FD), fibroxanthoma (nonossifying fibroma), cortical desmoid, desmoplastic fibroma, fibrosarcoma, and malignant fibrous histiocytosis (MFH). Benign fibrous lesions (FD, fibroxanthoma, and cortical desmoid) frequently demonstrate pathognomonic radiologic characteristics obviating the need for biopsy. Indeed, biopsy of these lesions can occasionally lead to confusion with more aggressive lesions. Desmoplastic fibroma and the malignant fibrous lesions (fibrosarcoma and MFH) often reveal nonspecific imaging features of a solitary nonmineralized lesion with aggressive characteristics. However, imaging is important as with other neoplasms in delineating the extent of involvement for staging purposes. This article reviews the spectrum of clinical characteristics, pathology, imaging appearances, treatment, and prognosis of lesions of fibrous origin in bone.

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.

Desmoplastic fibroma of the temporal bone

An unusual case of a desmoplastic fibroma of the temporal bone is presented. Although classified benign, this intraosseous lesion exhibits local aggressiveness and has a high potential for recurrence. This rare condition occurs predominantly in the mandible and in the long bones and is seldom seen in the calvarium. Here we add another case to the previously described eight in the skull and this is the fourth such case reported in the temporal bone. The clinical features, radiology, histopathology and the therapeutic considerations of this lesion in a 72-year-old female are discussed. In addition, a literature review of all the cases affecting the skull bones is presented.

Desmoplastic fibroma of bone: MRI features

Desmoplastic fibroma of bone is a very rare benign tumor, which may be locally aggressive. In contrast to the well-documented radiological appearance, the literature on MR imaging features of this tumor is scarce. The MR imaging characteristics in our case are compared to those previously reported. Although there is a considerable overlap in the MR imaging features with other bone tumors, an interesting MR feature of desmoplastic fibroma is the presence of low to intermediate signal intensity foci on T2-weighted images, which radiographically does not correspond to calcifications. This feature may help narrow the differential diagnosis.

MR findings of desmoplastic fibroma of the spine. A case report

We report on the MR imaging findings in a case of spinal desmoplastic fibroma (DF). DF of the bone is a rare, locally aggressive tumor. It is commonly located in long bones, pelvis or mandible. DF involving the spine is extremely rare and difficult to distinguish from other bony lesions such as giant cell tumor, chordoma and fibrous dysplasia of the spine. This case of DF of the spine showed MR findings similar to those of DF arising in the metaphysis of a long bone.

Odontogenic fibroma

The odontogenic fibroma is a rare tumor that has generated controversy, perhaps disproportionately to its importance in the family of odontogenic tumors. The clinical and radiographic features are well documented but the histologic aspects have generated controversy. The behavior is benign, and published accounts indicate a low recurrence rate following treatment by curettage. The tumor recognized by the World Health Organization (WHO) is the legitimate odontogenic fibroma. Histologic variants include the granular cell type and the hybrid odontogenic fibroma giant cell-like tumor. Although the extraosseous "peripheral" odontogenic fibroma presents as a gingival enlargement clinically indistinguishable from other gingival lesions, its histomorphology is similar to the central tumor. A normal dental follicle around the crown of an unerupted tooth may histologically mimic the odontogenic fibroma and other odontogenic tumors.

Synovial desmoplastic fibroblastoma of hip joint with bone erosion

A 78-year-old woman presented with pain at the left hip. Initial radiographs showed minimal age-related changes. Over the next 2 years she developed large erosions in the left femoral neck and proceeded to hip replacement. Histological examination showed bland spindle cells in a loose and hyalinised collagenous stroma considered to represent a desmoplastic fibroblastoma (collagenous fibroma). This is the first reported case of synovial desmoplastic fibroblastoma.

Desmoplastic fibroma of the zygoma

Desmoplastic fibroma is an exceedingly rare primary bone tumor. Previous reports have not included the presentation of this tumor associated with the zygoma. This report describes the unusual presentation and surgical management of a desmoplastic fibroma of the zygoma.

Desmoplastic fibroma of the mandible in a child: report of a case

A 6-year-old girl was seen with a history of progressive trismus and expansion of the right mandible over a 9-month period. Desmoplastic fibroma was diagnosed on biopsy. This report reviews the diagnostic criteria and surgical management of this uncommon primary bone tumor of the maxillofacial region.

Desmoplastic fibroma of the bone. A report of two patients, review of the literature, and therapeutic implications

BACKGROUND

Desmoplastic fibroma (DF) is an extremely rare bone tumor. The recommendations for therapy are often based on limited personal experience, and the rate of local recurrence in the published cases is very high. Therefore, an analysis of treatment results of published cases was performed. Furthermore, DNA analysis of the tumors from two patients was also performed.

METHODS

The clinical, radiologic, and histologic data of two patients with DF of the long bones are presented. DNA flow cytometry was performed on both DFs, three cases of abdominal fibromatosis, and three cases of extraabdominal fibromatosis. One hundred eighty-nine patients analyzed in the literature and our own 2 patients were evaluated with regard to epidemiologic, clinical, and histologic data, with particular emphasis on treatment results.

RESULTS

DNA analysis of the locally infiltrating tumors revealed indices of proliferation between 21.5% and 24%, noticeably elevated values in comparison with extraosseous desmoid tumors (8.04%). Magnetic resonance imaging (MRI) was most valuable for imaging the intraosseous and extraosseous extent of DF. The evaluation of 191 patients (189 from the literature, 2 of the authors) showed the numbers of males and females to be equivalent, with a mean age of 23 years. DF has been reported in almost all bones, with a tendency to occur in the mandible and the long bones. Approximately 12% of patients presented with a pathologic fracture (20 of 161 patients). Infiltrative growth in the soft tissue was documented in 48% of patients. Three patients developed metastases after local recurrence. Analyzing the treatment results, the authors found a recurrence rate of 55-72% after nonresection procedures, and 17% after resection. No recurrences are reported after resection with wide surgical margins. The recurrence rate of tumors of the extremities was 55%, and 25% of these patients eventually required an amputation.

CONCLUSIONS

Considering the "semimalignant" character of this entity and the poor treatment results in patients with recurrent tumors, marginal or wide resection for primary treatment is recommended. The superior imaging quality of MRI greatly facilitates preoperative planning.

Case report 847. Juxtacortical aggressive fibromatosis (desmoplastic fibroma) of the forearm

A case has been presented of a 14-year-old male patient who developed a fusiform mass on the volar aspect of his left forearm following two fractures. Microscopic features and plain radiography, CT, and MRI appearance of juxtacortical aggressive fibromatosis are discussed.

Extra-abdominal desmoid fibromatosis

Desmoid fibromatosis cannot be considered a biologically benign or innocuous lesion. In the head and neck it may be intraosseous (desmoplastic fibroma) or, more often, in soft tissues, with the highest incidence in the supraclavicular region of the neck. High recurrence and persistence rates, 50% or more, accompany intralesional or marginal excision. Keloids and proliferative scars, while stubborn in their resolution and potentially disfiguring, are reactive proliferative disorders of fibroblastic and myofibroblastic tissues.