Benign vascular lesions of bone: radiologic and pathologic features

 The benign vascular tumors of bone represent a diverse group of tumors that can present with a broad spectrum of clinical signs and symptoms. They can also present a significant diagnostic challenge due to their widely variable radiographic imaging and histologic features. Some of the tumors manifest as clearly benign lesions with tissue-specific diagnostic imaging features, while others have non-specific imaging features that may simulate malignant neoplasm. This article will provide a review of the nomenclature and the characteristic radiographic and pathologic features of the benign vascular lesions of bone. The information will aid in improving our diagnostic accuracy and enhance our understanding of the biologic potential of this diverse group of osseous lesions. Received: 14 May 1999 Revision requested: 17 June 1999, 6 October 1999 Revision received: 27 October 1999 Accepted: 27 October 1999     

Treatment of epithelioid hemangioendothelioma of bone using a novel combined approach

Radiofrequency (RF) treatment has been used for a variety of malignant and benign conditions. However, treatment of a bone malignancy has yet to be reported. The authors present a 21-year old woman with multifocal epithelioid hemangioendothelioma (EH) treated by a combination of surgical excision, chemotherapy and four RF ablations. Follow-up radiographs of the RF-treated sites reveal no evidence of recurrent disease 71, 58, 49 and 33 months, respectively, after treatment. Received: 15 August 2000 Revision requested: 12 September 2000 Revision received: 28 October 2000 Accepted: 4 November 2000     

Inflammatory myofibroblastic tumor of the lung (inflammatory pseudotumor): uncommon cause of solitary pulmonary nodule

Lung inflammatory myofibroblastic tumor is an uncommon cause of solitary lung nodule (0.7 % of lung tumors). The principal site of inflammatory pseudotumor is the lung, but it can also occur elsewhere in various organs. Although benign, they may be locally very aggressive. Recurrent and multifocal forms have been described. Since they are likely to mimic malignant neoplasms, accurate histopathologic diagnosis is necessary in order to guide appropriate surgical excision and avoid aggressive treatments. We report a case of lung involvement in a young adult with radiologic and pathologic correlations. Received: 26 February 1998; Revision received: 31 July 1998; Accepted: 14 September 1998     

Vascular bone tumors: a proposal of a classification based on clinicopathological, radiographic and genetic features

The classification of vascular bone tumors remains challenging, with considerable morphological overlap spanning across benign to malignant categories. The vast majority of both benign and malignant vascular tumors are readily diagnosed based on their characteristic histological features, such as the formation of vascular spaces and the expression of endothelial markers. However, some vascular tumors have atypical histological features, such as a solid growth pattern, epithelioid change, or spindle cell morphology, which complicates their diagnosis. Pathologically, these tumors are remarkably similar, which makes differentiating them from each other very difficult. For this rare subset of vascular bone tumors, there remains considerable controversy with regard to the terminology and the classification that should be used. Moreover, one of the most confusing issues related to vascular bone tumors is the myriad of names that are used to describe them. Because the clinical behavior and, consequently, treatment and prognosis of vascular bone tumors can vary significantly, it is important to effectively and accurately distinguish them from each other. Upon review of the nomenclature and the characteristic clinicopathological, radiographic and genetic features of vascular bone tumors, we propose a classification scheme that includes hemangioma, hemangioendothelioma, angiosarcoma, and their epithelioid variants.     

Intraosseous microcystic meningioma

Extradural ectopic meningioma is a rare tumor. We report on an example of microcystic meningioma arising in the skull of an elderly woman. Radiological examination revealed a localized osteolytic lesion in the left parietal bone. At surgery, it was discovered that the tumor was located within the skull without any evidence of extraosseous extension. The light microscopic, immunohistochemical and ultrastructural features were consistent with a microcystic variant of meningioma. To our knowledge, this is the first case of an intraosseous microcystic meningioma, and we believe that this type of meningioma should be considered in the differential diagnoses of myxoid bone tumors of the calvarium. Received: 10 January 2000 Revision requested: 21 February 2000 Revision received: 8 March 2000 Accepted: 13 March 2000     

Epithelioid hemangioma of bone

Although no specific radiographic appearance has emerged to date for the epithelioid subtype of hemangioma, these lesions most typically exhibit well-defined osteolysis. Other relatively common features include surrounding sclerosis, cortical expansion and cortical destruction. We present a case of epithelioid hemangioma of the spine with an unusual radiological appearance which to our knowledge has not previously been reported: diffuse sclerosis of the involved vertebral body. The diffuse sclerosis seen in this case resembles the osteosclerotic process seen not only in benign entities such as subacute and chronic osteomyelitis, but also in malignant lesions such as osteoblastic metastatic disease and lymphoma. Received: 28 July 2000 Revision requested: 8 September 2000 Revision received: 5 December 2000 Accepted: 6 December 2000     

Inflammatory myofibroblastic tumor of the temporal bone

Inflammatory myofibroblastic tumors include a diverse group of lesions characterized by inflammatory cell infiltration and variable fibrotic responses. Occurrence in the temporal bone is unusual. We present CT and MR imaging findings of an inflammatory myofibroblastic tumor of the temporal bone in a 26-year-old patient with repeated paroxystic episodes of rotatory vertigo that occurred over a few days. CT and MR imaging revealed a homogeneously enhancing soft-tissue mass of the right mastoid with bone erosion of the tegmen and extensive dural thickening. The mass resembled a malignant tumor, and the patient underwent an extended mastoidectomy through a retroauricular approach. Microscopic examination showed myofibroblastic spindle cells with mixed inflammatory infiltrate, and the pathologic diagnosis was inflammatory myofibroblastic tumor.     

Hyperfunctioning parathyroid carcinoma

Primary hyperparathyroidism is rarely caused by carcinoma. We report a patient who manifested many of the clinical and radiographic features of the disease. When encountering symptomatic hypercalcemia with or without a palpable neck mass, carcinoma should be considered in the differential diagnosis. Patient survival depends on an aggressive surgical approach to the primary lesion and recurrent disease. Received: 27 May 1999 Revision requested: 28 June 1999 Revision received: 22 September 1999 Accepted: 27 September 1999     

Solitary osteosclerotic plasmacytoma: association with demyelinating polyneuropathy and amyloid deposition

A 51-year-old man presented with a 1-year history of polyneuropathy necessitating the use of a wheelchair. Initial diagnosis was idiopathic chronic inflammatory demyelinating polyneuropathy (CIDP) and associated monoclonal gammopathy. Investigations for multiple myeloma, including bone marrow aspiration and biopsy, were negative. What was initially felt to be an incidental osteosclerotic focus noted on the radiographic bone survey was eventually shown to be a solitary osteosclereotic plasmacytoma with associated amyloid. This dramatically altered treatment. This case emphasizes the importance of including osteosclerotic plasmacytoma in the differential diagnosis of a focal sclerotic bone lesion in the clinical setting of polyneuropathy. These lesions are less likely to progress to multiple myeloma than lytic plasma cell neoplasms, and the presence of polyneuropathy often results in earlier diagnosis and treatment with enhanced prospect of cure. The finding of amyloid deposition within the osteosclerotic lesion may be of prognostic importance. Received: 30 November 2000 Revision requested: 15 January 2001 Revision received: 16 April 2001 Accepted: 18 April 2001     

Hemangioma of bone arising in the ulna: imaging findings with emphasis on MR

An 18-year-old woman presented with left elbow joint pain. Radiographs and computed tomographic scan showed a well-defined osteolytic lesion of the left ulna associated with a honeycomb appearance on the radiographs. Magnetic resonance images showed intermediate signal intensity on T1-weighted images and mixed intermediate and high signal intensities on T2-weighted images. Only the periphery of the lesion enhanced with intravenously injected gadolinium-diethylenetriamine pentaacetic acid. The lesion was curetted to avoid pathologic fracture, and a histologic diagnosis of cavernous hemangioma of bone was made. Hemangioma involving the ulna is rare, but should be included in the differential diagnosis of a radiographic osteolytic lesion with a honeycomb appearance. Received: 17 September 1999 Revision requested: 31 October 1999 Revision received: 10 December 1999 Accepted: 13 December 1999     

Recurrent malignant variant of phosphaturic mesenchymal tumor with oncogenic osteomalacia

Phosphaturic mesenchymal tumor is a rare neoplasm which causes osteomalacia or rickets. The tumor typically follows a benign clinical course. Even in the rare malignant cases, local recurrence and distant metastasis are uncommon. We report on an example of a malignant phosphaturic mesenchymal tumor which recurred several times over 16 years concurrently causing hypophosphatemia, bone pain, and osteomalacia. Following each surgery, symptoms and hypophosphatemia improved. The patient died of disease 17 years after the first surgery. Histologically, the initial tumor was composed of small spindle cells with clusters of giant cells, prominent blood vessels, poorly formed cartilaginous areas, and crystalline material. Cytological atypia was minimal. Following multiple recurrences, the tumor demonstrated areas of high-grade sarcoma exhibiting marked pleomorphism, numerous mitotic figures, and p53 overexpression. This case illustrates the potential lethality of incompletely removed phosphaturic mesenchymal tumors. Received: 3 January 2000 Revision requested: 4 August 2000 Revision received: 12 October 2000 Accepted: 18 October 2000     

Intracortical and subperiosteal aneurysmal bone cysts: a report of three cases

 Aneurysmal bone cyst of the long bones in a purely intracortical or subperiosteal location is unusual. Three such cases are reported, and the radiographic and pathologic differential diagnoses are discussed.Those subperiosteal or intracortical aneurysmal bone cysts with radiographic features similar to the intramedullary variety should suggest the same diagnosis. However, the radiographic features may be less specific, so that a diagnosis of aneurysmal bone cyst must be entertained when considering a subperiosteal or intracortical lytic lesion.     

原发性骨网状细胞肉瘤的临床及X线分析

目的探讨原发性骨网状细胞肉瘤的临床及X线表现,以期提高对本病的诊断和鉴别诊断水平。方法结合临床表现、手术及病理所见回顾性分析经病理证实的11例原发性骨网状细胞肉瘤的X线特点。结果长管状骨5例(45%),椎骨、肋骨及骨盆各2例(各占18%)。主要X线改变为溶骨性破坏,有软组织肿块者7例,病理骨折1例,骨膜反应仅见2例且较轻微。结论当X线发现溶骨性恶性病变伴软组织肿块,且临床症状较其他骨恶性肿瘤为轻者,应考虑原发性骨网状细胞肉瘤的可能,最后确诊有赖于病理学证实。     

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. Received: 24 May 1999 Revision requested: 30 June 1999 Revision received: 8 October 1999 Accepted: 14 October 1999     

Peripheral primitive neuroectodermal tumors. CT and MRI evaluation

The clinical, radiographic, and pathologic features of 17 patients with documented peripheral primitive neuroectodermal tumor (PNET) were evaluated in a retrospective study. The age at diagnosis ranged from 9 months to 46 years (median, 15.8 years). Primary sites of involvement were the abdomen (n = 8), extremities (n = 5), chest (n = 1), temporal bone (n = 1), maxilla (n = 1), and diploe (n = 1). At the time of diagnosis, six patients had distant metastases; all of these patients died, with an average survival of 8.8 months. Radiologic workup included standard radiographs, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy. The radiographic appearance of these tumors was not specific for differentiation of PNETs from other types of bone and soft tissue tumors. The typical appearance resembled large non-calcified, soft tissue masses with cystic or necrotic areas. Heterogeneous enhancement with intravenous contrast agents was evident on CT, as was an intermediate signal intensity on T1-weighted images and hyperintense signal on T2-weighted and STIR sequences. After gadolinium administration, variable enhancement was seen. MRI and CT were useful in predicting resectability, in detecting distant metastases, and in the evaluation of response to treatment. Surgery was performed in all cases, either for definitive diagnosis or for therapy. All patients received combined chemotherapy and radiotherapy and five patients received autologous bone marrow transplantation. Clinical follow-up was obtained over a mean period of 3 years (range 1 day to 6 years). Prognosis was poor with a median survival of 3.4 years. Our experience in 17 patients with peripheral neuroectodermal tumors indicates that although their radiologic features are non-specific, they should be included in differential diagnosis of soft tissue tumors of aggressive behavior, especially in a young age group. CT and MRI are useful in delineating the extent and resectability of tumor and in monotoring treatment.     

Characterisation of intra-articular soft tissue tumours and tumour-like lesions

The aim of this study was to describe a new magnetic resonance imaging (MRI) classification system for intra-articular soft tissue tumours based on the morphology of the lesion, with the aim to aid the differential diagnosis. We performed a retrospective review of 52 consecutive patients presenting to a specialist musculoskeletal oncology unit with a suspected intra-articular tumour. Lesions were categorised into one of four groups according to a simple classification system based on their morphological features on MRI. Distinct groupings of pathologies emerged corresponding to each of the morphological categories. Particularly when combined with radiographic features of calcification and bone erosion, certain patterns were found to be characteristic of specific diagnoses. For example multifocal, calcified lesions were found exclusively in synovial osteochondromatosis and diffuse synovitis with hypointense T2-weighted signal intensity was typical of pigmented villonodular synovitis. Certain combinations of imaging features such as diffuse solid lesions and focal lesions with bone erosion were commonly associated with malignant lesions. We suggest that by classifying intra-articular masses according to their morphological features on MRI, particularly when combined with simple radiographic features, an additional parameter may be generated to aid the radiologist in making a diagnosis. In addition, particular combinations of features provide 'red flags' to increase the index of suspicion for malignancy.     

Epithelioid hemangioendothelioma of bone A report of two cases and review of the literature

Epithelioid hemangioendothelioma is the prototype of a group of vascular tumors characterized by epithelioid or histiocytoid endothelial cells. Epithelioid hemangioendothelioma of bone is a rare lesion that constitutes fewer than 1% of primary malignant skeletal neoplasms. We describe two cases that illustrate the spectrum of radiographic features seen with this neoplasm, and also present its appearance on magnetic resonance imaging.     

Pseudo-osteomyelitic crisis upon presentation of Gaucher disease

We report on a 4-year-old boy adopted from Paraguay who presented with an acute onset of thigh pain. Initial clinical, imaging, and histopathologic findings suggested florid osteomyelitis. However, the development of pancytopenia on intravenous antibiotics prompted further investigation and the ultimate diagnosis of Gaucher disease. In retrospect, characteristic changes on conventional radiographic and MR images, as well as growth of a contaminant organism, pointed to the diagnosis of pseudo-osteomyelitis rather than osteomyelitis. Received: 21 November 2000 Revision requested: 13 December 2000 Revision received: 27 February 2001 Accepted: 28 February 2001     

Chronic inflammatory pseudotumor arising in the hepatobiliary-pancreatic system: progressive multisystemic organ involvement in four patients.

OBJECTIVE: Inflammatory pseudotumor is a benign process that can involve most organ systems. The purpose of this report was to evaluate the imaging features of multifocal chronic inflammatory pseudotumor in four patients who presented with clinical, radiographic, and biopsy evidence of pancreatic or biliary malignancy. CONCLUSION: To our knowledge, this is the first report in the radiology literature describing the imaging features of progressive multifocal inflammatory pseudotumor originating from a primary pancreatic or biliary focus. Even on retrospective review, no distinguishing imaging features were identified that could discriminate benign from malignant disease. These findings emphasize the importance of histopathologic analysis in the diagnosis of malignancy, particularly in patients with previously diagnosed inflammatory pseudotumor.