The role of magnetic resonance imaging in the diagnostic evaluation of malignant peripheral nerve sheath tumors.

BACKGROUND AND AIMS: Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of mortality in patients with neurofibromatosis type-1 (NF1)); however, they may also arise sporadically. Differences in magnetic resonance imaging (MRI) features between MPNSTs arising in NF1 subjects versus non-NF1 subjects have not been studied before. The accuracy of MRI in distinguishing MPNSTs from benign peripheral nerve sheath tumors (BPNSTs) has also been debated. The objective of this study was to determine the potential differentiating MRI features between (a) NF1-related and non-NF1-related MPNSTs and (b) MPNSTs and BPNSTs. MATERIALS AND METHODS: We retrospectively evaluated the MRI studies of 21 patients (12 NF1 subjects and nine non-NF1 subjects) with MPNSTs and 35 patients with BPNSTs. In all studies, the lesions were assessed in terms of size, margins, T1 and T2 signal characteristics, internal architecture, pattern of contrast enhancement, invasion of adjacent structures and necrosis/cystic degeneration as well as for the presence of tail-, target- and split-fat signs. RESULTS: MPNSTs of NF1 subjects occurred at an earlier age and displayed a higher incidence of necrosis/cystic degeneration compared with MPNSTs of non-NF1 subjects. Compared with BPNSTs, MPNSTs were significantly larger at the time of diagnosis and demonstrated a higher incidence of ill-defined margins (specificity 91%, sensitivity 52%) and invasion of adjacent structures (specificity 100%, sensitivity 43%). CONCLUSIONS: Differences exist between NF1-related and non-NF1-related MPNSTs regarding the age of occurrence and MRI appearance. In the MRI evaluation of peripheral nerve sheath tumors, the presence of ill-defined tumor margins and/or invasion of adjacent structures are highly specific for malignancy.

Ethical decision-making about older adults and moral intensity: an international study of physicians.

Through discourse with international groups of physicians, we conducted a cross-cultural analysis of the types of ethical dilemmas physicians face. Qualitative analysis was used to categorise the dilemmas into seven themes, which we compared among the physicians by country of practice. These themes were a-theoretically-driven and grounded heavily within the text. We then subjected the dilemmas to an analysis of moral intensity, which represents an important (albeit novel within healthcare research) theoretical perspective of ethical decision making. These constructs (ie, culture and moral intensity) represent salient determinants of ethical behaviour and our cross-cultural sample afforded us the opportunity to consider both the pragmatic aspects of culture, as they are perceived by physicians, as well as the theory-driven concept of moral intensity. By examining both culture and moral intensity, we hope to better elucidate the complexities of ethical decision-making determinants among physicians in their daily practice. Doing so may potentially have practical implications for ethics training of medical students and foreign physicians.

Intraosseous lipoma of the left frontoethmoidal sinuses and nasal cavity.

Intraosseous lipomas are very rare slow-growing benign tumors that may appear as congenital lesions or may be acquired (metaplasia from a pre-existing lipoma). Only a handful of head and neck cases have been reported in the literature. We present the first reported case of a solitary osteolipoma involving the sinonasal tract in a 66-year-old man with sinonasal symptoms. CT showed a lesion involving the left frontal sinus, extending into the ethmoid sinus with insinuation along the left middle turbinate. It appeared to be an atypical mass with areas of high attenuation (calcification) within.

Hyperphosphatasia with massive osteoectasia: a 45-year follow-up.

Hyperphosphatasia is a heterogeneous group of disorders characterized by a generalized skeletal disease and increased alkaline phosphatase. Increased bone remodeling secondary to increased osteoclastic activity appears to be the underlying feature of these disorders. These disorders include juvenile Paget's disease, expansile skeletal hyperphosphatasia, hyperostosis generalisata with striations, and Camurati-Engelmann's disease, type II. The genetic mutations for a number of these disorders have been identified. We present a patient with congenital hyperphosphatasia whose clinical and radiographic features were somewhat different from these other well-defined syndromes. The patient was followed for 45 years until his death of at age 49. The patient had massive osteoectasia with dense striations involving the entire shaft of his long bones. His spine, pelvis, short tubular bones, and calvarium were also involved. He suffered hearing loss and optic atrophy, but he kept his teeth throughout his life. He was tall with a marfanoid habitus, and he had hypogonadism and hypothyroidism. There was no evidence of mental retardation, and other laboratory studies where within normal limits. This case, as well as other manifestations of hyperphosphatasia, attests to the complexity of the bone remodeling system.

Oromaxillofacial osseous abnormality in Sturge-Weber syndrome: case report and review of the literature.

We report a case of a 17-month-old child affected by Sturge-Weber syndrome who had unusually rapid overgrowth of the left frontal, temporal, orbital, and maxillary regions. CT angiography illustrated osteohypertrophy with periostitis and associated soft tissue hypertrophy directly corresponding to the distribution of the cutaneous port-wine stain. Extended maxillectomy was performed because of rapid growth and clinical debilitation, with surgical pathology revealing juvenile ossifying fibroma.

Isolated lower extremity metastases, 9 years after initial diagnosis of retinoblastoma.

We report the development of isolated lower extremity metastases, in a child, 9 years after her initial diagnosis and treatment of bilateral infantile retinoblastomas. The radiographic, scintigraphic, computed tomographic, and magnetic resonance imaging findings are discussed. The dominant metastatic focus was blastic, involving the medial cuneiform. Additional occult lesions were found in the base of the second metatarsal, middle cuneiform, navicular and tibial diaphysis. An open biopsy confirmed the diagnosis. The occurrence of late distant metastases is rare in the USA.

Ewing's sarcoma presenting as a solitary cyst.

This case describes a 10-year-old girl who developed a Ewing's sarcoma in her proximal fibula. The radiologic features mimicked those of a unicameral bone cyst. The presence of pain and the atypical location led to a prompt biopsy and the correct diagnosis. The mechanism of this unusual radiographic presentation is discussed.

Intracortical chondroma: a report of two cases.

Intracortical chondromas are exceedingly rare lesions that have the histopathologic appearance of enchondromas, but are located within cortical bone. Two new cases of intracortical chondroma, one symptomatic and the other found incidentally, are presented and the entity's brief literature reviewed.

Heterotopic ossification: a review.

Heterotopic ossification is the formation of bone in the soft tissues. Soft tissue bone deposition may range from the minimal and inconsequential to massive and clinically significant. In some clinical settings it is a predictable finding with an unpredictable course and in other settings it may be diagnostically confounding. Heterotopic ossification may be encountered in clinically disparate disease processes and circumstances. We review the genetic, neurogenic, post-traumatic, post-surgical and "reactive" causes of heterotopic ossification and discuss some current concepts of its pathogenesis.

The effect of intravenous pamidronate on bone mineral density, bone histomorphometry, and parameters of bone turnover in adults with type IA osteogenesis imperfecta.

The type IA osteogenesis imperfecta (OI) phenotype is characterized by multiple fractures, blue sclerae, and minimal skeletal deformity without dentinogenesis imperfecta. The object of this study was to determine the effect of treatment with intravenous pamidronate (30 mg) every 3 months on bone density and bone histomorphometry in adults with type IA OI. After an initial iliac crest bone biopsy eight subjects, 5 women and 3 men, entered a treatment program lasting 21-30 months. Five subjects, all women, completed the study which included a posttreatment iliac crest bone biopsy. Pamidronate treatment led to significant increases in bone mineral density (BMD), measured by DXA, in the lumbar spine at 12 months (P = 0.05) and in the femur neck (P = 0.02) at 24 months. Significant increases in BMD were also seen in femoral trochanter at 12 months (P = 0.05) and at 24 months (P = 0.02), and in Ward's triangle at 12 months (P = 0.02) and 24 months (P = 0.05). Mean osteocalcin levels decreased 32%, C-terminal procollagen peptide and bone alkaline phosphatase declined 12% and 47% at 15 and 21 months, respectively. Deoxypyridinoline crosslink excretion decreased 31%. Posttreatment bone biopsy revealed a significant 6.3% increase in mean bone trabecular volume (P = 0.01). Mean cortical thickness increased from 848 mm to 1384 mm (P = 0.01) and cortical porosity decreased 13.2% (P = 0.01). Bone formation rate increased significantly in all 5 patients from 6.6 to 15.3 mm2/yr (P = 0.01). Mineral apposition rate was unchanged. These results indicate that intravenous pamidronate, 30 mg every 3 months, may have significant effects on bone density and histomorphometry in adults with type IA OI. Responses at higher doses remain to be evaluated.

Fibrous dysplasia involving the skull base and temporal bone.

OBJECTIVE: To gain a broader appreciation of the clinical presentation, operative treatment, and outcome of patients with fibrous dysplasia involving the skull base. DESIGN: Retrospective review of a clinical case series. SETTING: A single tertiary academic medical center. PATIENTS: Twenty-one patients with histopathologically confirmed fibrous dysplasia involving the skull base cared for over a 15-year-period (1983-1998). MAIN OUTCOME MEASURES: Clinical and radiographic location of the fibrous dysplasia lesions within the skull base, clinical presentation, surgical intervention, and clinical outcome were tabulated for each patient. RESULTS: The ethmoids were most commonly involved (71%), followed by the sphenoid (43%), frontal (33%), maxilla (29%), temporal (24%), parietal (14%), and occipital (5%) bones. The most common presenting features included atypical facial pain and headache, complaints referable to the sinuses, proptosis and diplopia, hearing loss, and facial numbness. Surgical treatment, guided by clinical presentation, ranged from simple biopsy with conservative follow-up to craniofacial resection. CONCLUSIONS: Fibrous dysplasia can present in myriad ways within the skull base. Modern imaging modalities and histopathologic analysis have made diagnosis relatively straightforward. Surgery, particularly in such a challenging region as the skull base, should be reserved for patients with functional impairment or a cosmetic deformity. Because of the benign nature of the condition, the surgery itself should be relatively conservative, with the primary goal being preservation of existing function.

A brachial plexopathy due to myositis ossificans. Case report and review of the literature.

Myositis ossificans (MO) is a disorder characterized by the intramuscular proliferation of fibroblasts and osteoblasts, with subsequent deposition of bone and cartilage. A typical clinical presentation involves traumatic injury to a young adult, usually localized to the thigh, buttock, or upper arm, with resultant MO and mildly restricted range of motion in adjacent joints. Rarely, MO is associated with peripheral neuropathies involving the radial, median, sciatic, and sural nerves. The authors present an unusual case of MO causing a brachial plexopathy. To their knowledge, this is the first description of such a presentation.

Disproportionately severe calcinosis cutis in an 88-year-old patient with CREST syndrome.

An 88-year-old woman with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias) presented with hyperglycemia, intravascular depletion, and atrial fibrillation. The patient was found to have unusually severe calcinosis cutis in both legs extending from the knees to the ankles bilaterally, as well as Raynaud's phenomenon, sclerodactyly, and telangiectasias. The patient was normocalcemic and normophosphatemic. Although subcutaneous calcification is often seen with CREST syndrome, this case is unusual in that the area of involvement was much larger than previously described. Furthermore, the amount of calcinosis was disproportionately severe and was the major cause of symptoms and disability compared with the other components of the syndrome.

Tumoral calcinosis of the spine: a study of 21 cases.

STUDY DESIGN: A retrospective study was conducted to investigate 21 patients found during spinal surgery to have paraspinal masses of dystrophic calcification (tumoral calcinosis). OBJECTIVES: To determine the magnetic resonance imaging characteristics of this disorder, and to document the associated spinal pathology. SUMMARY OF BACKGROUND DATA: Tumoral calcinosis usually is associated with hereditary disorders of calcium metabolism or renal dialysis. It also occurs in degenerated tissues in the absence of systemic disorders. Characteristically, calcific masses in the appendicular skeleton are visible on plain radiographs. Tumoral calcinosis has only rarely been reported in the spine. Documented patients have had an obvious calcific mass, and almost always the disorder has existed in other locations as well. Careful histologic study of specimens removed during spinal surgery suggests that tumoral calcinosis is common in the spine and usually is secondary to preexisting pathology. METHODS: This study involved 21 patients with lesions of tumoral calcinosis identified by histopathologic analysis of specimens removed during spinal surgery. The magnetic resonance images and the plain radiographs of the patients were reviewed and correlated with their clinical histories. RESULTS: In all the patients, the lesion of tumoral calcinosis was associated with a mass lesion seen on magnetic resonance imaging. Calcific masses were not apparent on plain films. In no case was the mass diagnosed before surgery as tumoral calcinosis. The magnetic resonance imaging changes were variously misinterpreted as neoplasms, infections, extruded disc material, or cysts. The observed features of tumoral calcinosis were those of an extradural mass showing a heterogeneous mixed-signal lesion that was identical on T1- and T2-weighted images. Characteristically, gadolinium did not enhance the lesions. CONCLUSIONS: Awareness of tumoral calcinosis of the spine may prevent unwarranted diagnoses of a more serious lesion in patients with characteristic magnetic resonance imaging changes. Also, this awareness may prevent pathologists from interpreting lesional tissue as nondiagnostic when other diagnoses are suspected clinically. This process may be a manifestation of degenerative spinal disease that has become so dominant that the underlying processes are obscured.

Primary resective shortening followed by distraction osteogenesis for limb reconstruction: a comparison with simple lengthening.

Resective distraction osteogenesis is a new approach to treat segmental diaphyseal bone defects by primary limb shortening and secondary distraction osteogenesis from the same site. A rabbit model was introduced to compare the bone-regeneration characteristics of this technique with those of simple lengthening procedures. Twenty-four skeletally mature New Zealand White rabbits were divided into two equal groups. In the test group, limbs were lengthened after a 10-mm segmental diaphyseal bone resection and limb shortening. In the control group, a simple subperiosteal osteotomy for limb lengthening was performed without resection. New bone formation was evaluated mechanically, radiologically, histomorphometrically, and densitometrically. Bone bridging occurred in all animals. Normalized mechanical values for the newly reconstructed tibiae demonstrated similar torsional stiffness (71+/-3.3 compared with 71+/-8.2%; p = 0.95) and strength (64+/-5.3 compared with 68+/-7.3%; p = 0.66) in the two groups. The average normalized callus diameter was significantly greater in the test group than in the control group (p < 0.01). The remodeling index calculated from densitometry, however, showed a significantly less progressed stage of remodeling in the test group (p < 0.05). Histomorphometric analysis of the callus center supported this finding, showing significantly lower values for trabecular thickness (p < 0.05) and total bone volume (p < 0.01) in the test group. The results demonstrated the possibility of new bone formation after resection and monofocal shortening. This suggests a new therapeutic option to treat diaphyseal segmental bone defects.

Case of an ivory vertebra.

The differential diagnosis of an osteoblastic vertebral lesion (ivory vertebra) includes metastatic prostate cancer, lung cancer, lymphoma, osteosarcoma and Paget's disease. We report a case of a man who was initially diagnosed with Paget's disease on vertebral biopsy. He failed to respond to conventional bisphosphate therapy. The review of the original biopsy specimen showed metastatic carcinoid tumor involving the bone marrow. The various features of carcinoid tumors metastasizing to the skeleton are briefly reviewed.

Synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome presenting as a primary calvarial lesion. Case report and review of the literature.

The synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a recently described, currently evolving clinical entity that groups together several idiopathic disorders of bone and skin formerly described under a variety of names. Among the spectrum of possible locations for the bone lesions, there is no previous report in the literature of primary involvement of the skull vault. A patient with primary involvement of the calvaria in the setting of SAPHO syndrome is described here, which, to the authors' knowledge, is the first report of such localization. The clinically and radiologically benign evolution of the different stages of the bone lesions is presented. The authors suggest that the SAPHO syndrome should be considered in the differential diagnosis of lytic, sclerotic, or hyperostotic lesions of the skull, particularly before considering invasive diagnostic procedures.