Multifocal eosinophilic granuloma with femoral epiphyseal lesion mimicking an aneurysmal bone cyst

Eosinophilic granuloma (EG) is a rare benign tumor-like disorder characterized by abnormal proliferation Langerhans cells. EG frequently presents as a solitary lesion in the axial skeleton and diaphysis long bones. Here we present the case of a 14-year-old male with multifocal EG with a lesion located in the femoral epiphysis mimicking an aneurysmal bone cyst that presented a diagnostic challenge. While the initial presentation of EG patients may appear uncommon, its overlapping features with other benign and malignant etiologies highlight the importance of increased awareness of this condition, as well as the need for an experienced multidisciplinary team in its diagnosis and treatment.     

Pituitary adenoma in McCune-Albright syndrome: MR demonstration

The magnetic resonance (MR) demonstration of a pituitary adenoma associated with McCune-Albright syndrome is presented. A useful role for routine MR imaging of the sella turcica in all cases of clinically suspected McCune-Albright syndrome is suggested. This is especially important in patients with leontiasis ossea secondary to polyostotic fibrous dysplasia involving the craniofacial bones and skull base.     

F-18 fluorodeoxyglucose (FDG) PET in the diagnosis of malignant transformation of fibrous dysplasia in the pelvic bones

Fibrous dysplasia (FD) is a benign dysplastic pathology of bone-forming mesenchymal cells, resulting in replacement of trabecular bone by abnormal fibrous and immature osseous tissue. FD can be either monostotic or polyostotic, is more often unilateral, and can be part of the McCune-Albright syndrome (MIM 174800). Sarcomatous degeneration in FD is rare, ranging from less than 1% in monostotic forms to 4% in the McCune-Albright syndrome. We report the case of a 59-year-old woman with monostotic FD of the left ischium, known for over 30 years, who developed sarcomatous transformation in a low-grade spindle-cell sarcoma. The value of F-18 fluorodeoxyglucose positron emission tomography in the early diagnosis of malignant transformation, the evaluation of distant metastasis, as well as monitoring the efficacy of chemotherapy are discussed.     

Malignant transformation of fibrous dysplasia into chondroblastic osteosarcoma

A case of malignant transformation of polyostotic fibrous dysplasia into maxillary chondroblastic osteosarcoma is presented. The clinical, radiographic, CT, MR imaging features and pathological findings of polyostotic fibrous dysplasia and its malignant transformation are described. Malignant transformation of fibrous dysplasia is rare and has not previously been described in the English literature in this location in McCune-Albright syndrome and in the absence of radiation treatment.     

Osteosarcoma in a patient with McCune-Albright syndrome and Mazabraud’s syndrome

Sarcomas infrequently develop in osseous sites of fibrous dysplasia. We report a patient with Mazabraud’s syndrome (polyostotic fibrous dysplasia and soft tissue myxomas) complicated by the development of osteogenic sarcoma in a bone affected by fibrous dysplasia. This is the third case of osteosarcoma within the small population of reported patients with Mazabraud’s syndrome. There may be an increased incidence of malignant transformation in these individuals’ dysplastic bones above that associated with patients suffering from fibrous dysplasia alone. Received: 31 December 1998 Revision requested: 31 January 1999 Revision received: 13 May 1999 Accepted: 14 May 1999     

Whole‐body MR imaging for the evaluation of mcCune‐albright syndrome

This paper is a detailed case study of a seven‐year‐old girl who developed precocious puberty. The young girl experienced bilateral breast enlargement, vaginal discharge, and multiple areas of “cafe‐au‐lait” pigmentation on the skin. The skeletal radiographs showed multiple bone lesions which were suggestive of polyostotic fibrous dysplasia. These findings were sufficient to establish the diagnosis of McCune‐Albright syndrome. Whole‐body MRI was used to assess the extent of the osseous lesions throughout the body. The MRI showed approximately the same number of osseous lesions compared to the skeletal radiographs. In addition, the MRI detected a cystic lesion localized in the pelvis that raised the possibility of an ovarian‐follicular cyst. This case suggests that whole‐body MRI might be a promising method for the evaluation and follow‐up of polyostotic fibrous dysplasia, a disease with diffuse involvement of the musculoskeletal system. J. Magn. Reson. Imaging 2010;31:706–710. © 2010 Wiley‐Liss, Inc.     

Bone scintiscanning in osteolytic lesions

Osteolytic lesions seen on plain radiographs can be caused by various disorders of the bones such as simple bone cyst, aneurysmal bone cyst, plasmacytoma, giant cell tumor, eosinophilic granuloma and tuberculosis. We studied prospectively Tc-99m-methylene diphosphonate bone scan findings in osteolytic lesions seen radiologically and followed them to histopathology. Interestingly, the scans in these patients helped to show if the lesions were monoostotic or polyostotic and, in some cases, ruled out malignant or infective etiology.     

Scintigraphic evaluation of polyostotic fibrous dysplasia

Bone scintigraphy is a sensitive imaging modality for detecting early lesions and polyostotic involvement in fibrous dysplasia. Common findings include multiple areas of focal uptake that are often unilateral and typically involve the ribs, tibia, femur, and craniofacial bones. A knowledge of various skeletal manifestations of fibrous dysplasia is helpful to distinguish it from Paget's disease, osteoblastic metastasis, and fractures. Several recent cases representing varying involvement of fibrous dysplasia are presented and the literature is reviewed.     

Fibrous dysplasia of bone: case report with autopsy study 80 years after the original clinical recognition of the bone lesions

 We present a report of the histological features of the bone lesions in a case of polyostotic fibrous dysplasia studied at autopsy in a patient aged 88 years. While much of the fibrous tissue of the lesions contained the trabeculae of non-lamellar bone that are a feature of fibrous dysplasia in young patients, other parts of the lesions showed evidence of osteoclastic remodelling of bone trabeculae, and even of the replacement of some of these structures by mature lamellar bone.     

Rare, primary iliac, pubic and ischial tumours in children (report of 14 cases)--Part II

14 cases of rare, primary iliac, pubic and ischial bone tumours or tumorous conditions are reported. These include aneurysmal bone cyst, eosinophilic granuloma, cavernous haemangioma, osteoid osteoma, fibrous dysplasia, fibrous dysplasia with sarcomatous degeneration, chondrosarcoma, lymphoma and atypical malignant histiocytosis. The possibilities to be considered in the accurate radiographic recognition of primary tumours of iliac, pelvic and ischial bones are discussed.     

Pseudoanaplastic tumors of bone

Objective To discuss the concept of pseudoanaplastic tumors of bone, which pathologically show hyperchromatism and marked pleomorphism with quite enlarged, pleomorphic nuclei, but with no to extremely rare, typical mitoses, and to propose guidelines for their diagnosis.Design and patients From a database of 4,262 bone tumors covering from 1971 to 2001, 15 cases of pseudoanaplastic bone tumors (0.35% of total) were retrieved for clinical, radiographic and pathologic review. Postoperative follow-up after surgical treatment was at least 3 years and a maximum of 7 years.Results There were eight male and seven female patients. Their ages ranged from 10 to 64 years with average of 29.7 years. Pathologic diagnoses of pseudoanaplastic variants of benign bone tumors included: osteoblastoma (4 cases), giant cell tumor (4 cases), chondromyxoid fibroma (3 cases), fibrous dysplasia (2 cases), fibrous cortical defect (1 case) and aneurysmal bone cyst (1 case). Radiography of all cases showed features of a benign bone lesion. Six cases, one case each of osteoblastoma, fibrous dysplasia, aneurysmal bone cyst, chondromyxoid fibroma, giant cell tumor and osteoblastoma, were initially misdiagnosed as osteosarcoma. The remaining cases were referred for a second opinion to rule out sarcoma.Conclusions Despite the presence of significant cytologic aberrations, none of our cases showed malignant behavior following simple curettage or removal of bony lesions. Our observation justifies the concept of pseudoanaplasia in some benign bone tumors as in benign soft tissue tumors, especially in their late evolutionary stage when bizarre cytologic alterations strongly mimic a sarcoma.     

Bone scintigraphy in common tumors with osteolytic components

Osteolytic lesions are frequently encountered in clinical practice. Radionuclide bone scans with technetium-99m-labeled diphosphonates are often performed in the evaluation of both solitary and multiple osteolytic lesions. In this pictorial review, we critically evaluate the current role of bone scan in common osteolytic tumors including aneurysmal bone cyst, simple bone cyst, fibrous dysplasia, nonossifying fibroma, giant cell tumor, eosinophilic granuloma, enchondroma, chondrosarcoma, osteosarcoma, Ewing sarcoma, myeloma, and metastases. The merits and limitations of bone scanning are emphasized.     

Mazabraud's syndrome: MRI evaluation

Mazabraud's syndrome represents a rare entity of myxomas that is associated with fibrous dysplasia (FD). We report a case of an intramuscular myxoma (IM), with Mc Cune–Albright syndrome and hypophosphatemia. In the same patient there was also a previous transformation to aneurysmal bone cyst in FD. The MRI imaging characteristics in correlation with pathology and a review of the literature are presented.     

Fibrous dysplasia localized to spine: a diagnostic dilemma

Fibrous dysplasia of the spine is uncommon, especially in monostotic form. Isolated vertebral involvement in polyostotic form is very rare. We report a case of polyostotic fibrous dysplasia with lesions localized to dorso-lumbar spine in a 45-year-old rheumatoid arthritis patient. No associated appendicular lesions, cutaneous manifestations or endocrinopathies were seen. The extreme rarity of this type of lesion can pose a diagnostic dilemma, and biopsy is required for diagnosis. The association with rheumatoid arthritis in our case seems to be a chance occurrence.     

Non-epiphyseal chondroblastoma arising in the iliac bone, and complicated by an aneurysmal bone cyst: a case report and review of the literature

Chondroblastoma is a benign bone tumor that typically arises in the epiphysis of a long bone. However, when it occurs in non-epiphyseal location in flat bones, it may create a diagnostic problem. We describe such a case of chondroblastoma arising in the iliac bone. A 29-year-old man was incidentally found to have a bony pelvic lesion while undergoing evaluation for Crohn’s disease. The radiographs and CT revealed an expansile lytic lesion in the right iliac bone. A core biopsy of the lesion was performed. The histopathology revealed the lesion to be a chondroblastoma with secondary features of aneurysmal bone cyst. An en bloc surgical resection of the tumor was performed.     

Scintigraphic manifestation of fibrous dysplasia

Scintigraphic manifestations of fibrous dysplasia were analyzed in 59 lesions of 26 patients (12 monostotic, 14 polystotic). Bone imaging with Tc-99m MDP revealed a high percentage of increased uptake of radioisotope in the lesions of fibrous dysplasia. Four (14%) of 29 cystic lesions and two (7%) of 30 lesions with the appearance of ground glass showed no increase in radioisotope uptake, although roentgenograms showed marked changes. Therefore, care must be taken in the diagnosis of fibrous dysplasia with bone imaging alone. Nuclear methods, however, are indispensable in evaluating the dynamic aspects of bone mineral behavior and in demonstrating disease where none was suspected, or in visualizing polyostotic involvement in those cases where only monostotic disease was suspected clinically. It is concluded that both scintigrams and roentgenograms are complementary procedures in the diagnosis of fibrous dysplasia.     

骨良性纤维组织细胞瘤临床及影像学分析

目的提高对骨良性纤维组织细胞瘤临床及影像学表现的认识。方法回顾分析14例经手术病理证实的骨良性纤维组织细胞瘤,所有病例均行X线检查,9例行CT检查,5例行MR I检查。结果男?女1?1,平均年龄29.6岁。临床以局部疼痛为主,2例可触到软组织肿物。14例共22处病灶。发病部位以四肢长骨居多,共17处病灶。9处病灶位于松质骨,8处位于骨干皮质。单发病变12例,多发病变2例。X线表现为偏心或中央型溶骨性破坏,单房或多房状,边界清楚,周围可有硬化边缘,部分病灶膨胀,皮质断裂,极少数病灶周围可见软组织肿物。少数破坏区内可有点片状钙化。CT对病灶内的钙化、囊性变、皮质断裂及周围软组织肿物显示比X线平片清楚。在MR I上一般表现为均匀的等T1W I长T2W I信号,有时信号不均匀,其内夹杂斑点状低信号影及无信号影。少数病灶在T1W I、T2W I上呈混杂信号。结论综合各种影像表现并结合临床特点,多数典型病例可明确诊断此病。     

Aneurysmal bone cyst of the paranasal sinuses associated with fibrous dysplasia: CT and MR findings

An aneurysmal bone cyst (ABC) in the paranasal sinuses is rare with only four previous cases having been described in the sphenoid and ethmoid sinuses. This report describes a case of an ABC involving the sphenoid and ethmoid sinuses as well as the upper nasal fossae. It is currently believed that a preexisting primary bone lesion, such as fibrous dysplasia, initiates an osseous arteriovenous fistula, which creates a secondary reactive lesion of bone, the ABC. These lesions, which are comprised of multiple cysts containing liquid blood and serous fluid, are optimally studied by a combination of CT and MR scans.     

Imaging features of subperiosteal aneurysmal bone cyst

PURPOSE: To analyze the imaging features of subperiosteal aneurysmal bone cyst. MATERIAL AND METHODS: The imaging material of 6 patients with biopsy-proved subperiosteal aneurysmal bone cyst was reviewed. Evaluation included patient demographics, lesion location and size, radiographic features, and intrinsic characteristics on CT and MR images. Review of histologic specimens was carried out by an experienced musculoskeletal pathologist. RESULTS: All lesions were located at the surface of long tubular bones (femur 3, tibia 2, humerus 1): 3 involved the diaphysis, 2 the dia/metaphysis, and 1 exclusively the metaphysis. Lesion size ranged from 2.5 to 6 cm in maximum diameter. Radiographs and CT images always showed a superficial bone defect, which on radiographs demonstrated irregular margins in 4 cases. All lesions caused an interrupted periosteal reaction (shell 3, trabeculated shell 1, Codman angle 2). MR images always showed a multicystic appearance with a hypointense rim, contrast-enhancing cyst walls, and fluid levels. Edema of adjacent soft tissues was present in all cases. CONCLUSION: Aneurysmal bone cyst in a subperiosteal location can demonstrate an aggressive radiographic appearance. MR imaging appears to be most valuable in the differential diagnosis, since it can demonstrate typical morphological features of the underlying process.