Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Brown tumors are erosive bony lesions caused by rapid osteoclastic activity and peritrabecular fibrosis due to hyperparathyroidism, resulting in a local destructive phenomenon. Although brown tumors are the most pathognomonic sign of hyperparathyroidism, they are very rarely observed at present as a result of early detection of hypercalcemia and elevated parathyroid hormone levels. The rare appearance of this entity in everyday practice is troublesome for both patients and physicians, because whenever it emerges, diagnosis could be mistaken for a giant cell tumor of the bone. However, clinical, biochemical, and radiologic findings can easily guide the diagnosis if one considers the full continuum of findings and their association with subject's medical history, instead of focusing only on bone lesion. In this report we present a case of brown tumor in the fibula with a short literature review, whose aggressive presentation and unawareness of the skeletal findings of hyperparathyroidism puzzled the caring doctors. This case illustrates the need for continuous vigilance of any physician, regardless of his specialty or his position in medical services structures.
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PMID:Brown tumor of the fibula: unusual presentation of an uncommon manifestation. Report of a case and review of the literature. 1824 53

Primary hyperparathyroidism is a fairly frequent pathologic diagnosis characterized by hypersecretion of parathyroid hormone, which results from adenomas in 80% to 85% of all cases. At clinical onset, the most common symptoms are hypercalcemia-related and some of them are pain due to kidney stones, polyuria, gastrointestinal, and neurologic disorders, whereas rarer symptoms are due to brown tumors and expansive lesions often found in fibrocystic osteitis. Brown tumors represent the terminal stage of the remodeling processes caused by an increased osteoclastic activity and fibroblastic proliferation during primary or secondary, albeit more seldom, hyperparathyroidism. The manifestation of primary hyperparathyroidism as skeletal disease has nearly disappeared in the last 2 decades. Cases are now most often diagnosed by the coincidental finding of asymptomatic hypercalcemia. Advanced screening techniques have made clinical evidence of bone disease rare. This article contains a case of brown tumor on the maxilla, palate, and mandible in addition to nephrectomy and proximal femur fracture, which are probably associated with primary hyperparathyroidism although less common nowadays. The diagnosis was suggested by the clinical history and confirmed by biochemical, radiologic, and histopathologic evidence. Excision of a parathyroid adenoma normalization of the metabolic status was then realized.
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PMID:Primary hyperparathyroidism presenting as a palatal and mandibular brown tumor. 1988 50

The extracellular calcium-sensing receptor (CaSR) plays a major role in the maintenance of a physiological serum ionized calcium (Ca2+) concentration by regulating the circulating levels of parathyroid hormone. It was molecularly identified in 1993 by Brown et al. in the laboratory of Dr. Steven Hebert with an expression cloning strategy. Subsequent studies have demonstrated that the CaSR is highly expressed in the kidney, where it is capable of integrating signals deriving from the tubular fluid and/or the interstitial plasma. Additional studies elucidating inherited and acquired mutations in the CaSR gene, the existence of activating and inactivating autoantibodies, and genetic polymorphisms of the CaSR have greatly enhanced our understanding of the role of the CaSR in mineral ion metabolism. Allosteric modulators of the CaSR are the first drugs in their class to become available for clinical use and have been shown to treat successfully hyperparathyroidism secondary to advanced renal failure. In addition, preclinical and clinical studies suggest the possibility of using such compounds in various forms of hypercalcemic hyperparathyroidism, such as primary and lithium-induced hyperparathyroidism and that occurring after renal transplantation. This review addresses the role of the CaSR in kidney physiology and pathophysiology as well as current and in-the-pipeline treatments utilizing CaSR-based therapeutics.
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PMID:Physiology and pathophysiology of the calcium-sensing receptor in the kidney. 1992 5

Brown tumors, a benign osteolytic process, are most commonly caused by hyperparathyroidism. Multiple bone involvement is relatively rare. There are many similarities in the radiologic and histological features of brown tumors and giant cell tumors (GCTs) of bone. Differentiation between the two lesions is dependent upon evaluation of serum biochemistry including serum calcium, phosphorous, and intact parathyroid hormone (I-PTH) levels. Herein, the case of a 32-year-old man with multiple osteolytic lesions of the left tibia and fibula as well as the fourth metacarpal bone of the left hand, previously misdiagnosed with multiple GCTs, is presented. Based on the radiographic findings and biochemistry results in a young adult patient, brown tumor was suspected and subsequently definitively diagnosed.
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PMID:Missed brown tumors in a young adult with decreased bone density. 2022 92

Parathyroid carcinoma (PTC) is a rare malignant disease that is usually hyperfunctioning, which produces an excess of parathyroid hormone. Hyperparathyroidism causes bone metabolism disorders, as osteopenia and sometimes brown tumors. Brown tumors are benign but locally aggressive bone lesions, whose differential diagnosis with metastases or other primary malignancies may be complicated. (99m)Tc-Sestamibi scan is the usual procedure for the detection of parathyroid pathology, with a sensitivity of 85-100% and specificity close to 100% in parathyroid adenomas, it having similar percentages in the detection of PTC. We present the case of a patient diagnosed of a malignant hyperparathyroidism associated with bone lesions in which the (99m)Tc-Sestamibi scan showed a false negative result in the detection of parathyroid condition. However, (18)F-FDG-PET/CT detected the PTC and helped in the differential diagnosis of associated bone lesions, which were finally confirmed as brown tumors.
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PMID:[False negative of the scintigraphy with 99mTc-sestamibi in parathyroid carcinoma with associated brown tumors. Contributions of the 18F-FDG-PET/CT]. 2134 24

Brown tumors (BTs) are relatively uncommon but they are serious complications of renal osteodystrophy. The objective of this study was to analyze the clinical, biological, and radiological characteristics of 16 patients with BTs provoked by secondary hyperparathyroidism (sHPT) and its response to the decrease in parathyroid hormone levels after parathyroidectomy (PTX). The management of that uncommon condition was also reviewed. We conducted a retrospective study including 16 end-stage renal disease patients who underwent subtotal PTX between 1997 and 2007 for severe sHPT with BTs. Our study included 10 men and 6 women, whose average age was 34 years. All patients were on dialysis. Ten of them were on dialysis for more than 5 years. The median duration on dialysis was 84 months. Patients included suffered from swellings associated with functional limitations. BTs had multiple locations in 7 patients. Jaw was the most frequent location (62%). Radiography and tomodensitometry demonstrated a mixed radio lucent and radio-opaque lesions with an expansion of the cortical bone. Bone scan demonstrated an increased uptake of lesions. Chirurgical treatment was indicated in all cases because of severe refractory sHPT with functional limitations and/or disfiguring deformities. In all cases, BTs stopped its progression and even decreased in size. However, it was insufficient in four cases, which required a surgical resection. PTX remains an efficacious approach in resistant cases of sHPT with persistent BTs.
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PMID:Brown tumors in dialyzed patients with secondary hyperparathyroidism: report of 16 cases. 2253 48

Brown tumours are classic bony lesions that arise as a result of the effect of parathyroid hormone on bone tissue in some patients with hyperparathyroidism. They are erosive bony lesions caused by rapid osteolysis and peritrabecular fibrosis, resulting in a local destructive phenomenon. Facial skeleton is involved in about 2% of all cases of which the mandible is frequently affected. A 35-year-old female who was diagnosed with osteomalacia and brown tumour in posterior mandible as the sign of secondary hyperparathyroidism secondary to vitamin D deficiency is presented.
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PMID:Brown tumour of the jaw. 2266 85

Brown tumors of bone are highly vascular, lytic bone lesions representing a reparative cellular process rather than a neoplastic process usually seen in patients with hyperparathyroidism. These tumors can behave aggressively and be destructive. We report a 49-year-old male patient who was admitted to our hospital with a long-term history of right shoulder and right hip pain. Multiple lytic and destructive bone lesions were found in X-ray graphy and CT images. These bone lesions mimicked multiple skeletal metastatic lesions and seemed to be those of the terminal stage of malignancy. PET scan was requested for the evaluation of FDG uptake of these lesions and to search the unknown primary tumor site. Positron emission tomography/computed tomography (PET/CT) images showed multiple hypermetabolic malignant or metastatic FDG avid bone lesions in skeletal system. However the biopsy results revealed no signs of malignancy and laboratory data showed elevated serum calcium, alkaline phosphatase, parathyroid hormone, low serum phosphate and parathyroid scintigraphy was performed. Adenoma in the left parathyroid gland was seen with Tc-99m MIBI parathyroid scintigraphy. Pathological results confirmed the diagnosis of parathyroid adenoma. Brown tumor is the potential cause of false-positive result in evaluation of a patient for unknown primary tumor or skeletal metastases with PET/CT imaging.
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PMID:Positron emission tomography/computed tomography imaging of brown tumors mimicking multiple skeletal metastases in patient with primary hyperparathyroidism. 2308 82

Brown's tumour is an uncommon focal giant cell lesion which arises as a result of the effect of increased parathyroid hormone on bone tissues in hyperparathyroidism. The mandible is the predominantly affected site in the maxillofacial area and a maxillary involvement is rare. The severity of the lesion, caused by a Brown's tumour, may lead to evident osteolysis and gross deformity in the maxillofacial region, which suggests the need for making an early diagnosis and giving prompt treatment. We are reporting a male patient who presented with a massive painful swelling in the right maxilla as the first manifestation of primary hyperparathyroidism, caused by a parathyroid adenoma.
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PMID:Diagnosis and clinico-radiological presentation in an aggressive maxillary brown tumour. 2499 55

Brown tumors are uncommon focal giant-cell lesions that arise as a direct result of the effect of parathyroid hormone on bone tissue in some patients that have hyperparathyroidism. Primary hyperparathyroidism could be caused by ectopic mediastinal parathyroid adenomas. The occurrence of lesions is explainable on embryologic basis. We present a 55-year-old Saudi woman with a rare case of brown tumor of the maxilla due to ectopic mediastinal parathyroid adenoma.
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PMID:Brown tumor in a patient with ectopic mediastinal parathyroid adenoma: A case report. 2540


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