Brown Tumors: A Case Report and Review of the Literature

Osteolytic Lesions (Brown Tumors) of Primary Hyperparathyroidism: A Report of Two Cases

Primary hyperparathyroidism is characterized by excessive production of parathyroid hormone. As the condition progresses, bone loss primarily occurs due to resorption. A complication of this condition is the formation of fibrotic and cystic changes in the bone, known as brown tumors. These lesions occur in areas of significant bone resorption, where fibrovascular tissue and giant cells replace bone tissue, often accompanied by hemorrhage and hemosiderin deposits. These brown lesions are rare, with an occurrence rate ranging from 1.5% to 4.5%. We present two cases of middle-aged women who had presentations consistent with hyperparathyroidism and presented with complications such as bone pain and numbness. Both underwent parathyroidectomy to manage the cause and recovered after the surgery. These cases emphasize the importance of recognizing primary hyperparathyroidism as a potential cause of abnormal lesions and highlight the diverse presentations associated with this condition.

Expect the unexpected: Brown tumor of the mandible as the first manifestation of primary hyperparathyroidism

Hyperparathyroidism (HPT) is a condition in which one or more parathyroid glands produce increased levels of parathyroid hormone (PTH), causing disturbances in calcium homeostasis. Most commonly HPT presents with asymptomatic hypercalcemia but the clinical spectrum may include disturbances reflecting the combined effects of increased PTH secretion and hypercalcemia. Brown tumors are rare, benign, tumor-like bone lesions, occurring in 1.5% to 4.5% of patients with HPT, as a complication of an uncontrolled disease pathway, and are nowadays rarely seen in clinical practice. The tumor can appear either as a solitary or multifocal lesion and usually presents as an asymptomatic swelling or a painful exophytic mass. Furthermore, it can cause a pathological fracture or skeletal pain and be radiologically described as a lytic bone lesion. The diagnosis of a brown tumor in HPT is typically confirmed by assessing the levels of serum calcium, phosphorus, and PTH. Although when present, brown tumor is quite pathognomonic for HPT, the histologic finding often suggests a giant cell tumor, while clinical presentation might suggest other more frequent pathologies such as metastatic tumors. Treatment of brown tumors frequently focuses on managing the underlying HPT, which can often lead to regression and resolution of the lesion, without the need for surgical intervention. However, in refractory cases or when dealing with large symptomatic lesions, surgical treatment may be necessary.

Large Brown Tumour of Mandible with Bleeding as Initial Presentation: A Case Report

Brown Tumour or Osteitis fibrous cystic or Von-Recklinghausen disease of bone is a non-malignant condition due to abnormal metabolism of bones in hyperparathyroidism. Although pathognomonic of hyperparathyroidism, brown tumours are rare and only case reports are found in literature. We report a case of brown tumour of mandible with recurrent episodes of bleeding. A 46 year old male patient presented in emergency with bleeding from ulceroproliferative mass from left floor of mouth. After control of bleeding, radiological, laboratory and histopathological investigations were done that led to the diagnosis of brown tumour of mandible in the presence of parathyroid adenoma of left lower parathyroid gland. Left upper and lower parthyroidectomy was done with segmental resection of mandible with mass and titanium plating. Brown tumour of facial bones is a rare entity. Very rarely it can reach enormous sizes to cause bleeding. Although parathyroidectomy and correction of parathormone levels cause regression of small tumours, large brown tumours with complications should be managed with surgical resection and reconstruction.

Multiple Bone Cysts Caused by Hyperparathyroidism: A Case Report and Review of the Literature

Background

Brown tumor, a skeletal complication of severe hyperparathyroidism, comprises reparative granulation tissue and proliferating fibrous tissue with hemosiderin deposition. Multiple brown tumors are extremely rare complications of primary hyperparathyroidism.

Case Report

A 41-year-old woman presented with pain in the left knee. Radiography showed multiple cystic lesions in both femurs and the left proximal tibia, and additional radiography showed multiple cystic lesions in the left humerus and ulna. Magnetic resonance imaging (MRI) revealed multiple cystic lesions in the bilateral femurs, left proximal tibia, and ilium. Laboratory tests revealed hypercalcemia (albumin-corrected calcium level, 13.9 mg/dl), hypophosphatemia (phosphate level, 1.6 mg/dl), elevated level of alkaline phosphatase level (614 U/l), and markedly elevated parathyroid hormone (PTH) level (1,070 pg/ml; normal range=10-65 ng/l). 99mTc-hexakis-2-methoxyisobutyl-isonitrile scintigraphy revealed tracer accumulation in the left upper parathyroid gland, which was consistent with parathyroid tumor. Although resection of the parathyroid tumor was planned, the patient developed parathyroid apoplexy before tumor excision. After the parathyroid apoplexy, serum calcium and PTH levels temporarily normalized. Resurgence of the PTH level was observed 2 years after the diagnosis, and the patient underwent left upper parathyroidectomy. One year after the tumor excision, the patient had no symptoms, and MRI showed shrinkage of the cystic bone lesions.

Conclusion

This report emphasizes the importance of considering hyperparathy-roidism as a differential diagnosis for patients with multiple bone lesions.

A Rare Presentation of a Bi-Maxillary Brown Tumour due to Secondary Hyperparathyroidism

Brown tumours are localized bone lesions, seen in patients with high parathyroid hormone levels. This can be due to primary hyperparathyroidism, which occurs more often in neoplasms of the parathyroid gland or due to secondary hyperparathyroidism more often seen as a result of renal impairment. Facial involvement is rare, with most reports focusing on long and axial bones. However, the mandibular bone is often the only bone affected. Here, we report a rare case of a bi-maxillary attainment of brown tumour in a patient with secondary hyperparathyroidism due to chronic kidney disease.

Palatal swelling revealing a secondary hyperparathyroidism: A case report

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Secondary hyperparathyroidism is a common complication of chronic renal disease.

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Brown tumors are rare benign bone tumors caused by exposure to excessive parathyroid hormone secretion during hyperparathyroidism.

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Head and neck brown tumors are rare.

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Brown tumors regress spontaneously, completely or at least partially after parathyroidectomy.

Diagnosis and Treatment of Brown Tumor in the Femur Induced by Parathyroid Carcinoma: A Case Report

Brown tumors are rare destructive bone lesions caused by hyperparathyroidism. As their clinical symptoms, radiographic findings, and laboratory results closely mimic those of metastatic tumors or multiple myeloma, the diagnosis may often be mistaken. We report a case of a 61-year-old woman with brown tumors in both femurs due to parathyroid carcinoma. The patient presented with multiple osteolytic lesions that caused pain in the right thigh. Whole-body computed tomography (CT), including the neck, suspected a parathyroid tumor, and a biopsy of the bone lesion revealed no malignancy. Following parathyroidectomy, she was diagnosed with a brown tumor with hyperparathyroidism due to a very rare parathyroid carcinoma. Although the right femoral lesion was indicated as an impending fracture, conservative treatment was performed because of the instability of her general condition after parathyroidectomy and her wishes. Bone remodeling of the right femur progressed, and the patient was ambulatory; however, 9 months postoperatively, the patient fell, developed a pathological fracture, and underwent internal fixation. When multiple osteolytic bone lesions are present, CT imaging of the neck should be performed to determine the possibility of a brown tumor due to parathyroid disease. Bone lesions of brown tumors are known to be naturally cured after treatment for hyperparathyroidism. However, when the lesion of a brown tumor in the femur is an impending fracture, prophylactic internal fixation is recommended aggressively if the patient's general condition permits.

Pathological ankle fracture due to brown tumour: atypical presentation of low serum vitamin D with normal parathyroid hormone and bone profile

Osteoclastomas or brown tumours are named as such due to increased vascularity, subsequent haemorrhage and haemosiderin deposition giving the lesion a reddish brown appearance under gross microscopic examination. It is due to an increase in parathyroid hormone activity from several causes, such as parathyroid adenomas, renal impairment and low vitamin D levels. The lesions increase the tendency of the bone to fracture. The challenging aspect of the diagnosis is that a histological diagnosis without immunohistochemistry is impossible to make. This is because, without special staining, brown tumours cannot be differentiated from giant cell tumours, which are also classed as benign but can be locally destructive and has potential for malignant transformation. Once tissue diagnosis is confirmed as a brown tumour, then aggressive forms of treatment are not needed, and they generally resolve once the underlying cause is treated. We describe a woman in her 80s who presented to the local Orthopaedic service with a pathological ankle fracture due to a brown tumour.

Primary hyperparathyroidism-induced brown tumors caused by parathyroid carcinoma: a case report and literature review

Brown tumors represent a benign disease that is induced by primary or secondary hyperparathyroidism, with the pathological feature of osteitis fibrosa cystica. Primary hyperparathyroidism caused by parathyroid carcinoma resulting in brown tumors is extremely rare. Herein, we report the case of a 60-year-old male patient who was admitted for giant cell tumors of the bone with local pain and limited movement of the left knee joint. With early detection of multifocal osteolytic bone lesions, hyperparathyroidism (parathyroid hormone: 2365.00 pg/mL), and parathyroid cancer, the diagnosis of brown tumors was confirmed without any unnecessary or harmful interventions. Thereafter, he underwent parathyroidectomy, from which postoperative pathology confirmed parathyroid carcinoma, and total knee arthroplasty to restore movement of the knee joint. Seven months after surgery, the left knee joint had good range of movement. This case emphasizes that detecting patients’ parathyroid hormone levels should not be neglected when diagnosing multifocal osteolytic bone lesions. A comprehensive analysis combining clinical symptoms, imaging, and laboratory tests is conducive to accurate disease assessments and avoiding unnecessary or even survival-impairing surgery. However, when the tumor involves a large joint or seriously affects joint movement, surgery may be worth considering.

Misdiagnosis of brown tumour caused by primary hyperparathyroidism: a case report with literature review

BACKGROUND

Brown tumour is a rare tumour-like lesion of the bone, which is considered as an end-stage lesion of abnormal bone metabolism caused by persistently high parathyroid hormone (PTH) levels. Brown tumour can be found in any part of the skeleton; in some cases, it can occur in multiple bones and can be easily misdiagnosed as a metastatic tumour.

CASE PRESENTATION

We report the case of a 44-year-old man who presented to the Department of Oncology in our hospital with a 2-month history of local pain in his left shoulder joint. The initial diagnosis was an aneurysmal bone cyst by biopsy, for which the patient underwent tumour resection surgery. The diagnosis of a malignant tumour was made again following postoperative pathological examination. The pathological sections and all clinical data were sent to the Department of Pathology of the First Affiliated Hospital of Sun Yat-sen University; the diagnosis made there was brown tumour. His blood PTH level was 577 pg/ml (15-65 pg/ml). Colour Doppler ultrasonography of the parathyroid gland suggested a parathyroid adenoma. For further treatment, the left parathyroid adenoma was removed by axillary endoscopic resection. Postoperatively, a pathologic examination was performed, and the diagnosis of a parathyroid adenoma was confirmed. One year after the surgery, the left humerus was completely healed, and the left shoulder joint had a good range of movement.

CONCLUSIONS

In summary, histopathological diagnosis is not sufficient for the diagnosis of brown tumours. A comprehensive analysis combining clinical symptoms with findings of imaging and laboratory tests is also required. Generally, the treatment of brown tumour includes only partial or complete resection of the parathyroid glands. However, when the tumour is large, especially when it involves the joint, surgery is indispensable.

A Unique Case of Aggressive Central Giant Cell Granuloma in a 10-Year-Old Boy With 16p13.11 Microdeletion Syndrome

Central giant cell granuloma (CGCG) is a rare disease characterized by sporadic, benign, intraosseous mandibular lesions of unknown etiology. Histologically, these lesions are indistinguishable from brown tumors of hyperparathyroidism and cherubism, and occasionally have been associated with different syndromes raising a question for genetic etiology. The CGCG has varied presentation ranging from nonaggressive and indolent to aggressive, destructive, and recurrent, often posing diagnostic and therapeutic challenges. Herein, we present the first case of a 10-year-old boy with CGCG and 16p13.11 microdeletion syndrome, highlight the diagnostic challenges inherent to this heterogeneous disorder, and discuss the genetics and treatment approaches of these complex lesions.

Mandibular Brown Tumor as a Result of Secondary Hyperparathyroidism: A Case Report with 5 Years Follow-Up and Review of the Literature

Background: Brown tumor is a rare skeletal manifestation of secondary hyperparathyroidism. Although diagnosis of the disease is increasingly seen in early stages due to improved screening techniques, some patients still present in a progressed disease stage. The treatment depends on tumor mass and varies from a conservative approach with supportive parathyroidectomy to extensive surgical resection with subsequent reconstruction. Case presentation: We report a case of extensive mandibular brown tumor in a patient with a history of systemic lupus erythematosus, chronic kidney disease, and secondary hyperparathyroidism. Following radical resection of the affected bone, reconstruction could be successfully performed using a free flap. Conclusions: There were no signs of recurrence during five years of close follow-up. Increased awareness and multidisciplinary follow-ups could allow early diagnosis and prevent the need for radical therapeutical approaches.

Multiple brown tumors with primary hyperparathyroidism mimicking bone metastases []

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Brown tumor is the differential diagnosis with bone metastasis.

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Brown tumor is a rare benign lesions in skeletal system, which caused by uncontrolled primary or secondary hyperparathyroidism.

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Serum phosphate, serum calcium and PTH level measurements are helpful diagnostic tools.

Multiple osteolytic lesions are usually associated with bone metastasis. However, brown tumor should also be included in the differential diagnosis. Brown tumor is a rare benign lesions in skeletal system, encountered in patients with uncontrolled primary or secondary hyperparathyroidism. In our case report, we present a 35-year-old female with multifocal brown tumor that difficultiy in differential diagnosis of metastasis of malignant parathyroid. Additionally, the treatment and follow up after parathyroidectomy are also emphasized.

Methods

The SCARE 2020 Guideline [1].

Three Rare Concurrent Complications of Tertiary Hyperparathyroidism: Maxillary Brown Tumor, Uremic Leontiasis Ossea, and Hungry Bone Syndrome

A 48-year-old woman in her 40’s with end-stage renal disease and tertiary hyperparathyroidism (HPT) presented for a rapidly progressive maxillary tumor. Initial workup was notable for elevated intact parathyroid hormone (PTH) and diffuse thickening of skull and facial bones on computed tomography, and maxillary tumor biopsy with multinucleated giant cells. She underwent subtotal parathyroidectomy (with removal of a parathyroid adenoma and 2 hyperplastic glands) and partial resection of maxillary brown tumor. The patient’s post-operative course was complicated by hungry bone syndrome, with hypocalcemia refractory to aggressive calcium repletion. Teriparatide (recombinant PTH) was utilized with rapid resolution of hypocalcemia. To our knowledge, this is the first case of maxillary brown tumor in tertiary HPT to be reported in the USA. This case also supports teriparatide as a novel therapeutic for hungry bone syndrome refractory to aggressive calcium repletion.

Craniofacial Brown Tumor in Patients with Secondary Hyperparathyroidism to Chronic Renal Failure: Report of Two Cases in Cipto Mangunkusumo Hospital

Brown tumor is a bone lesion that arises in the setting of excess osteoclast activity in hyperparathyroidism. It consists of fibrous tissue, woven bone, and supporting vasculature, while contains no matrix. The characteristic of brown-colored lesion is a result of hemosiderin deposition into the osteolytic cysts. Two cases of young women aged 26 and 29 years old, respectively, are known with a history of end-stage renal disease (ESRD). Dialysis is performed two times/week over the last 7 years. Our patients presented with an intraoral mass of the hard palate since 12 months ago and decreased body height of 10 cm. The lesion causes difficulties in swallowing and talking. Laboratory workup showed elevated parathormone or PTH (3.391 pg/mL and >5.000 pg/mL). Neck ultrasound showed enlargement of the parathyroid glands. Supporting examination to diagnose brown tumor are neck ultrasound, CT of the neck, and parathyroid sestamibi scan. We performed parathyroidectomy. Pathology revealed hyperplasia of the parathyroid. The tumor regressed significantly within 2 weeks following the surgery, and we still observe tumor regression as well as reduction in PTH level. As clinicians, we should be alert to other possible causes of bony lesions. Clinical examination, laboratory finding, and imaging present important information to diagnose brown tumor.

Facial Dysmorphism Due to Multiple Brown Tumors Secondary to Large Parathyroid Adenoma, Diagnosed on 99mTc-Sestamibi Parathyroid Scintigraphy

Brown tumors are an uncommon entity associated with hyperparathyroidism. Initially described with primary hyperparathyroidism, with the widespread use of dialysis, they were also seen to be associated with secondary and tertiary hyperparathyroidism. These are lytic, expansile lesions causing bony pains, and depending on the size and extent, skeletal dysmorphism. The present case illustrates the detection of parathyroid adenoma with multiple brown tumors on ^99mTc-sestamibi parathyroid scintigraphy in a patient presenting with facial dysmorphism and multiple bony pains.

Osteolytic lesions (brown tumors) of primary hyperparathyroidism misdiagnosed as multifocal giant cell tumor of the distal ulna and radius: a case report

Background

Brown tumors represent a rare clinical manifestation reported in approximately 3% of patients with primary hyperparathyroidism and correspond to radiologically osteolytic lesions with well-defined borders in different parts of the skeleton.

Case presentation

We report the case of a 53-year-old white man who presented to our hospital with osteolytic lesions of his distal ulna and radius, causing pain and swelling of 2-month duration. A subsequent biopsy revealed histological features consistent with giant cell tumor and a complete resection of his distal ulna was followed, along with curettage and cementoplasty of the distal radial metaphysis. Two weeks later, he was re-admitted with diffuse musculoskeletal soreness, anorexia, constipation, nausea, and localized abdominal pain and multiple osteolytic lesions on plain radiographs. A histopathological examination of the ulna and radius specimens showed similar findings and, given the multifocality, brown tumors related to primary or secondary hyperparathyroidism was included in the differential diagnosis. A laboratory examination showed high total serum calcium (14.5 mg/dl) and low serum phosphorus and 25-hydroxyvitamin D levels. Primary hyperparathyroidism was suspected and confirmed by the elevated parathyroid hormone levels of 1453 pg/mL. At radiological work-up, using computed tomography, ultrasonography, and parathyroid subtraction technetium-99m sestamibi scintigraphy, a 4.5 × 2.5 × 3.2 cm mass emanating from the right lobe of his thyroid gland was detected, displaying extensive uptake in the right lower parathyroid gland. After appropriate medical support including hyperhydration and high doses of diuretics and diphosphonates, his laboratory profile normalized and he underwent total thyroidectomy with removal of the parathyroid glands. Our patient is now recovering 12 months after surgery, with normal values of serum parathyroid hormone and calcium levels. The lytic bone lesions have almost disappeared and no other additional orthopedic intervention was necessary.

Conclusions

The present case report emphasizes the need of inclusion of brown tumors in the differential diagnosis of multifocal osteolytic bone lesions, in order to avoid harmful surgical interventions. Laboratory testing of serum phosphate, calcium levels, and parathyroid hormone levels should always be included in the routine survey of patients with multifocal osteolytic lesions.

Brown Tumor as an Index Presentation of Severe Vitamin D Deficiency in a Teenage Girl

Brown tumor is a non-neoplastic fibro-cystic expansile bone lesion caused by parathyroid hormone excess. It has been commonly described in patients with primary hyperparathyroidism and secondary hyperparathyroidism due to chronic kidney disease. However, it is very rare to encounter a brown tumor in the setting of nutritional vitamin D deficiency. We describe the case of a 16-year-old girl who presented with brown tumor-like lytic lesion of femur caused by severe longstanding vitamin D deficiency. Treatment with elemental calcium and cholecalciferol resulted in correction of hyperparathyroid state, with the resultant disappearance of the bony lesion and remarkable symptomatic improvement. Unnecessary orthopaedic intervention may be avoided using a high index of suspicion and performing targeted investigations in such cases.

Unusually Large Brown tumor of Mandible in a Case of Secondary Hyperparathyroidism Mimicking Cherubism

We report here a case of unusually large brown tumor of mandible mimicking cherubism in a patient with secondary hyperparathyroidism (HPT). The patient is a young male with a large head and a protruding jaw with an open mouth appearance. Initial clinical appearance looked like cherubism. However further clinical, biochemical, and radiological evaluation revealed a large brown tumor in a case of prolonged secondary HPT, which was confirmed on histopathology. All of the typical advanced radiological features of HPT were noted, highlighting the severity of progression of the disease. This case emphasizes the need for surveillance of serum calcium levels on routine biochemical investigations as to enable an early diagnosis of HPT. With timely proper management, such cases should be on the decline in the future.