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Alveolar soft-part sarcoma of the masseter and mandibular ramus: Report of a case and review of the literature
Posted: Fri Nov 23, 2018 6:39 am
by D.ap
Abstract
Alveolar soft-part sarcomas are clinically and morphologically distinct soft-tissue sarcomas, with an unknown histogenesis. When the tumors affect the region of the head and neck, they are often located in the orbit and tongue. We report a case of an alveolar soft-part sarcoma in the left masseter of a 28-year-old female. The patient had chronic pain and paresthesia of her left lower lip. Panoramic radiography and computed tomography showed a well-delimited radiolucent mass in the left ramus. An incisional biopsy was performed, and the sample submitted for histopathological study. The tumor showed positive periodic acid-Schiff diastase-resistant granules. Immunohistochemically, the tumor cells were diffusely
positive for myoglobin, and focally positive for actin and desmin.
https://www.sciencedirect.com/science/a ... 0213000548
Spontaneous regression in alveolar soft part sarcoma: Case report and literature review
Posted: Fri Nov 23, 2018 6:49 am
by D.ap
Abstract
Sarcomas are a type of malignant tumors that arise from connective tissue. They are most of the time found in extremities We are presenting a case of adult male patient, who was found to have huge abdominal mass and multiple gastric and duodenal polyps. Pathological diagnosis for all lesions was Alveolar soft part sarcoma. Although he complained from metastasis to both lungs and right atrium, all these deposits regressed spontaneously. Patient stated that he used some herbs (Teucrium polium, Cat Thyme) prescribed for him. No chemotherapy or radiotherapy was given. The duration of regression was about 5 months before other lesions appeared. Later on, he died secondary to brain metastasis. ASPS is a rare type of sarcomas that affect primarily the lower limbs. This tumor does rarely metastasize to the gastrointestinal tract.
https://www.researchgate.net/publicatio ... ure_review
Spontaneous regression in alveolar soft part sarcoma: Case report and literature review
Posted: Fri Nov 23, 2018 6:53 am
by D.ap
Figure 6 myoglobin
Prevention of hypoxia by myoglobin expression in human tumor cells promotes differentiation and inhibits metastasis
Posted: Fri Nov 23, 2018 8:12 am
by D.ap
Abstract
“As a tumor grows, it requires increased amounts of oxygen. However, the tumor blood vessels that form to meet this demand are functionally impaired, leading to regions of hypoxia within the tumor. Such hypoxia is one of the hallmarks of malignancy and is thought to promote a number of tumorigenic properties. Here, we sought to determine how tumors without hypoxia would progress by engineering A549 human lung carcinoma cells to ectopically express myoglobin (Mb), a multifunctional heme protein that specializes in oxygen transport, storage, and buffering. Mb expression prevented the hypoxic response in vitro and delayed tumor engraftment and reduced tumor growth following xenotransplantation into mice.
Experimental tumors expressing Mb displayed reduced or no hypoxia, minimal HIF-1α levels, and a homogeneously low vessel density. Mb-mediated tumor oxygenation promoted differentiation of cancer cells and suppressed both local and distal metastatic spreading. These effects were primarily due to reduced tumor hypoxia, because they were not observed using point-mutated forms of myoglobin unable to bind oxygen and they were abrogated by expression of a constitutively active form of HIF-1α. Although limited to xenograft models, these data provide experimental proof of the concept that hypoxia is not just a side effect of deregulated growth but a key factor on which the tumor relies in order to promote its own expansion.”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2662552/