Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alpha isoform of smooth muscle actin (SMA) expression has been reported in giant cell tumour of bone (GCTB) and other benign and malignant bone tumours, but the pattern of SMA expression and the precise nature of SMA-expressing cells in these lesions is uncertain. We determined by immunohistochemistry the expression of SMA and other muscle and vascular markers in normal bone, GCTB and a wide range of primary benign and malignant bone tumours. Cultured stromal cells of GCTB, chondroblastoma (CB), and aneurysmal bone cyst (ABC) were also analysed for SMA expression. SMA was only noted in blood vessels in normal bone. SMA was expressed by mononuclear stromal cells (MSC) cultured from GCTB, ABC and CB. SMA was strongly and diffusely expressed by MSC in non-ossifying fibroma, fibrous dysplasia, and "brown tumour" of hyperparathyroidism. SMA expression was also noted in GCTB, ABC, CB, chondromyxoid fibroma, malignant fibrous histiocytoma of bone and osteosarcoma. Little or no SMA was noted in Langerhans cell histiocytosis, simple bone cyst, Ewing's sarcoma, osteoblastoma, osteoid osteoma, enchondroma, osteochondroma, chondrosarcoma, myeloma, lymphoma, chordoma and adamantinoma. Our findings show that there is differential SMA expression in primary bone tumours and that identifying the presence or absence of SMA is useful in the differential diagnosis of these lesions. The nature of SMA-expressing cells in bone tumours is uncertain but they are negative for desmin and caldesmon and could represent either myofibroblasts or perivascular cells, such as pericytes.
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PMID:Smooth muscle actin expression in primary bone tumours. 2254 53

Positron emission tomography with the radiotracer 18F-fluoro-2-deoxy-d-glucose (FDG) plays an important role in the evaluation of bone pathology. However, FDG is not a cancer-specific agent, and knowledge of the differential diagnosis of benign FDG-avid bone alterations that may resemble malignancy is important for correct patient management, including the avoidance of unnecessary additional invasive tests such as bone biopsy. This review summarizes and illustrates the spectrum of benign bone conditions that may be FDG-avid and mimic malignancy, including osteomyelitis, bone lesions due to benign systemic diseases (Brown tumor, Erdheim-Chester disease, Gaucher disease, gout and other types of arthritis, Langerhans cell histiocytosis, and sarcoidosis), benign primary bone lesions (bone cysts, chondroblastoma, chondromyxoid fibroma, desmoplastic fibroma, enchondroma, giant cell tumor and granuloma, hemangioma, nonossifying fibroma, and osteoid osteoma and osteoblastoma), and a group of miscellaneous benign bone conditions (post bone marrow biopsy or harvest status, bone marrow hyperplasia, fibrous dysplasia, fractures, osteonecrosis, Paget disease of bone, particle disease, and Schmorl nodes). Several ancillary clinical and imaging findings may be helpful in discriminating benign from malignant FDG-avid bone lesions. However, this distinction is sometimes difficult or even impossible, and tissue acquisition will be required to establish the final diagnosis.
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PMID:Benign Bone Conditions That May Be FDG-avid and Mimic Malignancy. 2858 74