The term “dedifferentiation” was classically used in sarcoma pathology to refer to tumors in which a high-grade, undifferentiated sarcoma, or a high-grade sarcoma showing heterologous ...differentiation, arises from a pre-existing neoplasm of borderline or low-grade malignancy. The best recognized examples of this include dedifferentiated liposarcoma, arising from atypical lipomatous tumor/well-differentiated liposarcoma, and dedifferentiated chondrosarcoma, arising from grade 1 hyaline chondrosarcoma of bone. In the overwhelming majority of cases, this dedifferentiated, high-grade sarcoma presents as a macroscopically visible mass, adjacent to and clearly distinct from the pre-existing low-grade lesion. It is less well appreciated that dedifferentiation may also occur in a so-called “mosaic pattern,’ in which the high-grade component is intimately admixed with elements of the precursor lesion, forming only microscopically apparent foci. This mosaic or co-mingling pattern of dedifferentiation is also reflected in the MR imaging appearance. In contrast to the classic pattern of dedifferentiation in which there are two distinct juxtaposed masses with different signal intensities and enhancement patterns, such changes are not seen in mosaic dedifferentiation. The imaging features of this pattern of dedifferentiation have not been described. In this report we describe the imaging features of two patients with mosaic pattern dedifferentiation, one with liposarcoma and one with chondrosarcoma. In both cases the precursor lesion was correctly diagnosed by pre-biopsy imaging, but the presence of high-grade sarcoma was not recognized.
Imaging Appearance of Diffuse Neurofibroma Hassell, Douglass S; Bancroft, Laura W; Kransdorf, Mark J ...
American journal of roentgenology (1976),
03/2008, Volume:
190, Issue:
3
Journal Article
Peer reviewed
The purposes of this study were to describe the imaging appearance of diffuse neurofibroma in 10 patients and to summarize demographic data on a large group of patients.
Retrospective review of the ...pathology and radiology teaching databases at two institutions yielded the cases of 339 patients with a pathologic diagnosis of diffuse neurofibroma. Diagnostic-quality images were available for 10 patients. Images from MRI (n = 8), CT (n = 5), and sonographic (n = 1) examinations were evaluated for lesion location, size, depth of involvement, growth pattern, and intrinsic signal intensity, attenuation, or echogenicity. Demographic information, associated lesions, and tumor location were recorded for all patients.
Among 10 patients with images, eight of whom had neurofibromatosis, diffuse neurofibroma involved the skin and subcutaneous tissues (n = 9) and frequently extended to the fascia over muscle (n = 6). Plaquelike (n = 5) and infiltrative (n = 3) growth patterns were most common. One lesion had a mixed growth pattern. Prominent internal vascularity was common (n = 5). MRI signal intensity and CT attenuation were typically nonspecific. Enhancement was intense in all five patients with contrast-enhanced MR examinations. Including patients with and those without images, 349 diffuse neurofibromas were present in 339 patients. The mean patient age was 35.1 years. Lesions involved the extremities (n = 120), trunk (n = 122), head and neck (n = 98), and deep structures (n = 9).
Diffuse neurofibroma frequently grows as a plaquelike or infiltrative lesion involving the skin and subcutaneous tissues. Prominent internal vascularity is common. There is a much wider soft-tissue and age distribution and association with neurofibromatosis than previously reported.
Eosinophilic Fasciitis: Spectrum of MRI Findings Moulton, Stacy J; Kransdorf, Mark J; Ginsburg, William W ...
American journal of roentgenology (1976),
03/2005, Volume:
184, Issue:
3
Journal Article
Peer reviewed
Our objective was to describe the spectrum of MRI features of eosinophilic fasciitis.
MRI findings in eosinophilic fasciitis are characteristic and consist of abnormal fascial signal intensity and ...enhancement, both of which are directly proportional to disease activity. MRI provides a useful aid for diagnosis and a marker for disease activity and response to treatment.
Shoulder arthroplasty is a common orthopedic procedure with a complication rate reported to be as high as 39.8% and revision rates as high as 11%. Symptoms related to postoperative difficulties ...include activity-related pain, decreased range of motion, and apprehension. Some patients report immediate and persistent dissatisfaction, although others report a symptom-free postoperative period followed by increasing pain and decreasing shoulder function and mobility. Imaging plays an important role in diagnosing postoperative complications of shoulder arthroplasties. The imaging algorithm should always begin with radiographs. The selection of the next imaging modality depends on several factors, including findings on the initial imaging study, clinical suspicion of an osseous versus soft-tissue injury, and clinical suspicion of infection.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
The current standard of practice for the detection of osseous metastatic disease is the conventional bone scan of the entire body using technetium-99m methylene diphosphonate (Tc-99m MDP). Although ...Tc-99m MDP scintigraphy is sensitive for the detection of advanced skeletal metastatic lesions, early involvement may be missed because this technique relies on the identification of the osteoblastic reaction of the involved bone rather than the detection the tumor itself. Positron emission tomography (PET) has proven to be the gold standard in metabolic imaging. Fluorine -18 deoxyglucose (FDG) provides a means of quantitating the glucose metabolism, with the amount of tracer accumulation reflecting the glucose metabolism: high-grade malignancies tend to have higher rates of glycolysis than do low-grade malignancies and benign lesions; therefore, high-grade malignancies have greater uptake of FDG than that of low-grade or benign lesions. Positron emission tomography has been shown to be superior to scintigraphy in the detection of metastases because it detects the presence of tumor directly by metabolic activity, rather than indirectly by showing tumor involvement due to increased bone mineral turnover. This has allowed the detection of metastatic foci earlier with PET than with bone scintigraphy. Although the spectrum of PET applications is unknown, it now is approved for the diagnosis, staging and restaging of many common malignancies and has shown efficacy for the detection of osseous metastasis from several malignancies including lung carcinoma, breast carcinoma, and lymphoma.
Shoulder pain is one of the most common reasons for musculoskeletal-related physician visits. Imaging plays an important role in identifying the specific cause of atraumatic shoulder pain. This ...review is divided into two parts. The first part provides a general discussion of various imaging modalities (radiographs, arthrography, nuclear medicine, ultrasound, CT, and MRI) and their usefulness in evaluating atraumatic shoulder pain. The second part focuses on the most appropriate imaging algorithms for specific shoulder conditions including: rotator cuff disorders, labral tear/instability, bursitis, adhesive capsulitis, biceps tendon abnormalities, postoperative rotator cuff tears, and neurogenic pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
The purpose of this study was to describe the spectrum of radiologic and pathologic manifestations of calcific tendinitis involving bone.
We retrospectively reviewed 50 cases of calcific tendinitis ...involving underlying bone. Clinical data reviewed included patient age and sex and lesion location. Images reviewed included radiographs (n = 44), CT scans (n = 13), MRIs (n = 16), and bone scintigrams (n = 13). Radiologic examinations were evaluated for the presence of cortical erosion, periosteal reaction, and marrow extension. Pathology confirmation was available in 37 cases.
The average age of patients was 50 years (range, 16-82 years), with 29 female patients (58%). Calcific tendinitis with associated bone involvement was seen most commonly in the femur (40%) and the humerus (40%). Concretions were most commonly solid-appearing (50%). Cortical erosion was the most common manifestation of osseous involvement (78% of cases). Marrow involvement was shown in 18 (36%) of 50 cases. Marrow extension was most commonly seen in the lesser and greater tuberosities of the humerus, which accounted for 61% (11/18) of cases. Focal increased radionuclide uptake was seen in 13 (100%) of 13 cases.
Calcific tendinitis presenting with osseous destruction, marrow changes, and soft-tissue calcifications may be confused with neoplasm both radiologically and pathologically. Recognition of the atypical presentation of this common disease may prevent unnecessary biopsy.
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