We have previously demonstrated that thyroid hormone controls growth hormone synthesis in GH1 cells and that the induction of the growth hormone response by glucocorticoid appears to be highly dependent on thyroid hormone action. Thyroid hormone induces growth hormone synthesis approximately 5-to 20-fold and cortisol increases this response 2-to 6-fold further. Long-term kinetics of the growth hormone response show that, without added thyroid hormone, cortisol can induce a small-growth hormone response after 48 hr of incubation. Sodium dodecyl sulfate/polyacrvlamide gel electrophoresis of proteins synthesized in intact celis demonstrates that the cortisol enhancement of growth hormone synthesis in cells incubated with thyroid hormone is a relatively selective process. Quantitation of growth hormone mRNA levels by cell-free protein synthesis demonstrates that the regulation of growth hormone synthesis by thyroid and glucocorticoid hormones is explained by a synergistic pretranslational control mechanism, presumably at the level of the growth hormone gene.

A 27-year-old woman developed a rapidly progressive left orbital tumor which extended into the cranial fossa. MRI revealed a heterogenous enhancing lesion confined to the left frontal bone and superior orbit. An excisional biopsy was performed and examination of the specimen showed findings diagnostic of a high-grade0020myxofibrosarcoma. Myxofibrosarcoma is a fibroblast-derived soft tissue neoplasm with up to a 60% local recurrence rate and metastasis may be associated with intermediate to high grade tumors. Complete excision with postoperative adjuvant radiation therapy with chemotherapy was performed.Myxofibrosarcoma (MFS), formerly known as a myxoid or a myxoid variant of malignant fibrous histiocytoma (MFH), was first proposed in 1977 as a group of malignant lesions which show a broad spectrum of nuclear pleomorphism, cellularity and proliferative activity. 1 Over the ensuing years, this tumor has increasingly been recognized as a distinct neoplasm of fibroblastic origin without histiocytic differentiation. As a consequence, the category of socalled myxoid MFH was dropped by the World Health Organization classification in 2002, and MFS was added to the category of fibrous tumors.2 MFS is a malignant mesenchymal tumor that occurs in older adults. The most common locations of MFS are the limb and limb girdle followed by the head and neck, retroperitoneum and mediastinum.3 , 4 There has been one case described of MFS occurring in the orbit. 5 Herein, we report an additional case of myxofibrosarcoma of the orbit and brefly review the clinical, radiologica, and histopatholgoic characteristics of this tumor. Case ReportA 27-year-old woman complained of a painless lump in her left upper eyelid and left eyebrow area for the past six weeks. She had mild diplopia and no history of trauma or surgery. Her best corrected vision was 20/25 and 20/20, right and left eyes, respectively. Slit lamp examination was unremarkable. A 3×3 cm firm mass was palpable in the superotemporal orbital region. Magnetic resonance imaging (MRI) demonstrated a mass involving the frontal bone at the lateral superior aspect of the orbit, extending superiorly into the frontal bone.A biopsy of the lesion was performed and histopathologic examination showed a tumor composed of loosely coherent sheets of cells, including elongated spindle-shaped cells with fusiform nuclei and prominent nucleoli and round cells with hyperchormatic, round nuclei. Some of these cells contained abundant eosinophilic cytoplasm. There were greater than 20 Immunohistochemical stains were strongly positive for vimentin, for Ki67 in 20% of nuclei, and negative for desmin, mygenin, SMA and S100 in the tumor. The findings were consistent with a high grade myxofibrosarcoma.The patient underwent a left fronto-orbital craniotomy for tumor resection. Intraoperatively, the tumor had a relatively well-defined capsule and was found to extend into the lateral orbital region. The bone in the frontal orbital area including the rim was substantially destroyed by the tumor. The hi...

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