Differentiating Brown Tumor From Bone Metastasis in Parathyroid Cancer Using 18 F-FDG PET and 99m Tc-MIBI SPECT.

ABSTRACT: A 69-year-old woman presented with a right clavicle pain. CT revealed a pathological fracture of the right clavicle, multiple osteolytic lesions, and a left cervical mass. 18 F-FDG PET/CT demonstrated a marked FDG uptake in the cervical mass and osteolytic lesions indicative of metastatic parathyroid cancer. 99m Tc-MIBI SPECT/CT revealed either faint or no uptake in the osteolytic lesions. However, a histopathological analysis after a parathyroidectomy and right clavicle biopsy confirmed the diagnosis of parathyroid cancer and the presence of benign brown tumors secondary to hyperparathyroidism. Postoperative imaging showed sclerotic change and a decreased FDG uptake in the bone lesions.

Multiple brown tumors: a bone complication due to long-term untreated pseudohypoparathyroidism.

Bone lytic lesions are a possible complication of pseudohypoparathyroidism type 1B, in undertreated adult patients. Whole body [18F] F-fluorocholine PET/CT is a useful imaging tool to assess brown tumor progression in this context. We describe the case of a 33-year-old woman, referred for the diagnostic evaluation of lytic bone lesions of the lower limbs, in the context of asymptomatic pseudohypoparathyroidism. She had been treated with alfacalcidol and calcium during her childhood. Treatment was discontinued at the age of 18 years old because of the lack of symptoms. A femur biopsy revealed a lesion rich in giant cells, without malignancy, consistent with a brown tumor. Laboratory tests showed a parathyroid level at 1387 pg/ml (14-50). Whole-body Fluorocholine PET/CT revealed hypermetabolism of bone lesions. The final diagnosis was brown tumors related to hyperparathyroidism complicating an untreated pseudohypoparathyroidism. Genetic testing confirmed PHP type 1B. Pseudohypoparathyroidism with radiographic evidence of hyperparathyroid bone disease, is a very rare condition due to parathyroid hormone resistance in target organs, i.e., kidney resistance, but with conserved bone cell sensitivity. It has been reported in only a few cases of pseudohypoparathyroidism type Ib. Long-term vitamin D treatment was required to correct bone hyperparathyroidism. With this rationale, the patient was treated with calcium, alfacalcidol, and cholecalciferol. One-year follow-up showed complete resolution of pain, improvement in serum calcium, and regression of bone lesions on [18F]F-fluorocholine PET/CT. This case illustrates the usefulness of [18F]F-fluorocholine PET/CT for the imaging of brown tumors in pseudohypoparathyroidism type 1B, and emphasizes the importance of calcium and vitamin D treatment in adult patients, to avoid the deleterious effects of high parathyroid hormone on skeletal integrity.

Localization of Brown Tumors With 18 F-Fluorocholine PET/CT Imaging in Severe Primary Hyperparathyroidism.

ABSTRACT: We present the case of a 68-year-old woman with a painful tibial tumor and fatigue. Histology and laboratory studies were consistent with a brown tumor secondary to initially unrecognized, severe primary hyperparathyroidism. 18 F-fluorocholine PET/CT revealed a large hypermetabolic parathyroid mass and multiple bone foci considered as brown tumors. Unilateral neck exploration confirmed a large parathyroid adenoma. Serum calcium and parathyroid hormone levels normalized quickly, and symptoms subsided gradually after parathyroidectomy. Brown tumors are a rare complication of severe hyperparathyroidism. 18 F-fluorocholine PET/CT allows the localization of parathyroid adenomas and brown tumors, and can be used as a single imaging modality.

Uncommon presentation of brown tumours revealing hyperparathyroidism: Three case reports.

Brown tumours (BTs) are focal bone lesions encountered in patients with uncontrolled hyperparathyroidism (HPT). They are due to a proliferation of multinucleated giant cells in osteolytic lesions. Because of early screening of bone metabolism disorders, BTs are rare bone manifestations. More importantly, they scarcely reveal the disease. We demonstrate through these two cases reports unusual locations of BT complicating the course of HPT due to parathyroid hyperplasia.

Coexistence of brown tumors due to secondary hyperparathyroidism and prostate cancer in a patient.

We present the case of a 65-year-old man with brown tumors due to secondary hyperparathyroidism. Magnetic resonance imaging of the pelvis showed multiple lesions with expansive bone appearance. Additionally, prostate cancer was diagnosed during this time. For this reason, differential diagnosis was performed through biopsy of the right iliac bone lesion. Brown tumors are caused by osteoclastic activity and fibroblast proliferation; the differential diagnosis of these bone lesions includes giant tumors, metastases, Paget's disease, and paraneoplastic syndrome with high levels of parathyroid hormone-related peptide (PTHrP). This case report describes the coexistence of two pathologies that could explain these images. In this report, we present a case of a 65-year-old man with brown tumors due to secondary hyperparathyroidism and prostate cancer. In this setting, histologic confirmation is recommended.

Spinal Cοrd Compression Secondary to Brοwn Tumοr as First Manifestation of Primary Hyperparathyroidism.

BACKGROUND: Brown tumors (BTs) represent the typical nonmalignant lesions of hyperparathyroidism. Mandibles, ribs, and large bones are the most usual localization of BT. The diagnosis of these tumors requires biological and radiologic assessments. Their treatment is essentially based on parathyroidectomy. CASE DESCRIPTION: The present case report describes a patient with primary hyperparathyroidism who developed a cervical BT revealed by slow spinal compression. CONCLUSIONS: The brown tumor, when localized at the level of the spine, can be life-threatening and must be managed as soon as possible.

18F-Fluorocholine PET/CT Imaging of Brown Tumors in a Patient With Severe Primary Hyperparathyroidism.

Brown tumors are rare skeletal anomalies occurring in patients with hyperparathyroidism and exposing patients to pathological fractures. We report the case of a 26-year-old woman with severe primary hyperparathyroidism (calcemia, 2.9 mmol/L; parathyroid hormone, 59 pmol/L) who underwent F-fluorocholine (FCH) PET/CT before parathyroidectomy. FCH PET localized the hyperfunctioning parathyroid gland and showed multiple foci in correspondence with bone lytic lesions on CT. Those lesions were not visible on the Tc-MIBI dual-phase scintigraphy. The pathology of one of the FCH-positive bone lesions corresponded to a brown tumor related to hyperparathyroidism.

Brown tumor of the thoracic spine presenting with paraplegia in a patient with peritoneal dialysis.

Secondary and tertiary hyperparathyroidism is an important problem of chronic kidney disease. Brown tumor is a benign, unusual, reactive lesion as a result of disturbed bone remodeling, from long-standing increase in parathyroid hormone level. Brown tumors may cause morbidity due to pressure symptoms on neural structures and spontaneous bone fractures. Herein, we presented a peritoneal dialysis patient with tertiary hyperparathyroidism under calcand calcitriol treatment for 4 years due to refusing of the parathyroidectomy operation. She admitted to hospital for sudden onset back pain with difficulty in gait and walking, and imaging studies showed an expansile mass lesion in the thoracic spine. She was operated for mass and diagnosed with brown tumor. After operation, she lost the ability of walking than become paraplegic and she underwent rehabilitation program. Preventive measures including calcitriol and cinacalcet may cause a modest decrease in parathyroid hormone levels but it should be remembered for the development of bone complications such as brown tumor formation in patients with moderate elevated PTH levels, especially those with tertiary hyperparathyroidism. Parathyroidectomy should be performed without delay in these cases.

Complex spinal fixation of a cervical vertebra Brown tumour: report of an unusual case.

Brown tumours affecting the cervical spine are a rare but recognised complication of renal failure-related secondary hyperparathyroidism. We present a case of a 26 year-old female with radiculopathy who was managed successfully with 360° cervical spine fixation and parathyroidectomy.

Suspected Malignant Lesion of the Hip Resolves after Parathyroidectomy: Osteitis Fibrosa Cystica (or Brown Tumor): A Case Report.

We present a case of osteitis fibrosa cystica (OFC), also known as "brown tumor." A 55-year old female was admitted to the hospital with several months of right hip pain that was becoming more severe. A malignant lesion of the pelvis was suspected after initial imaging studies. Significant hypercalcemia led to a diagnosis of hyperparathyroidism and ultimately a benign parathyroid adenoma. Surgical excision of the adenoma resulted in full resolution of the tumor in her pelvis as well as her pain. It is important to keep OFC, or brown tumor, in your differential diagnoses when presented with a bone lesion.

Solid aneurysmal bone cyst of the humerus mimics metastasis or brown tumor.

Solid aneurysmal bone cyst (ABC) is a rare subtype of ABC that most commonly involves the small bones of the hands or feet. We present a case of a solid ABC of the distal humerus in a 52-year-old man with a history of chronic kidney disease and renal cell carcinoma. On imaging with plain radiographs, CT, and MRI, this expansile lucent lesion with solid internal enhancement had an appearance that overlapped with metastasis or brown tumor of hyperparathyroidism. On 18F-FDG PET-CT, this lesion was hypermetabolic with an SUVmax of 9.9. Only 37 cases of solid ABC have previously been reported to involve the long bones in the literature, and only 4 in the humerus. We review the clinical, imaging, and histopathological findings and differential diagnosis of solid ABC, and highlight the usefulness of identifying the USP6 gene rearrangement on FISH to distinguish this lesion from other lesions with secondary ABC formation.

Osteitis fibrosa cystica masquerading as bone neoplasm.

A 50-year-old female patient with no significant medical history presented with left knee pain. Radiographs of the knee showed a circumferential swelling of the distal femur suggestive of neoplasia. Further evaluation revealed multiple lesions in the left iliac bone and proximal femur. Biopsy was suggestive of a reparative granuloma or an aneurysmal bone cyst. Laboratory assessment showed hypercalcaemia and elevated parathyroid hormone consistent with severe primary hyperparathyroidism. Osseous survey was significant for salt and pepper appearance of the skull. Ultrasound of the neck and 99mTc-sestamibi parathyroid scintigraphy localised a left parathyroid adenoma/carcinoma. Parathyroidectomy was successful, and a large parathyroid adenoma was excised. Six months later, the patient was doing fine with her gait returning to normal. On follow-up 2 years later, she had no recurrence of the lesions.

A patient with a history of breast cancer and multiple bone lesions: a case report.

BACKGROUND: Long-term severe hyperparathyroidism leads to thinning of cortical bone and cystic bone defects referred to as osteitis fibrosa cystica. Cysts filled with hemosiderin deposits may appear colored as "brown tumors." Osteitis fibrosa cystica and brown tumors are occasionally visualized as multiple, potentially corticalis-disrupting bone lesions mimicking metastases by bone scintigraphy or 18F-fluorodeoxyglucose positron emission tomography. CASE PRESENTATION: We report a case of a 72-year-old white woman who presented with malaise, weight loss, and hypercalcemia. She had a history of breast cancer 7 years before. The practitioner, suspecting bone metastases, initiated bone scintigraphy, which showed multiple bone lesions, and referred her to our hospital for further investigations. Laboratory investigations confirmed hypercalcemia but revealed a constellation of primary hyperparathyroidism and not hypercalcemia of malignancy; in the latter condition, a suppressed rather than an increased value of parathyroid hormone would have been expected. A parathyroid adenoma was found and surgically removed. The patient's postoperative course showed a hungry bone syndrome, and brown tumors were suspected. With the background of a previous breast cancer and lytic, partly corticalis-disrupting bone lesions, there was a great concern not to miss a concomitant malignant disease. Biopsies were not diagnostic for either malignancy or brown tumor. Six months after the patient's neck surgery, imaging showed healing of the bone lesions, and bone metastases could be excluded. CONCLUSIONS: This case shows essential differential diagnosis in a patient with hypercalcemia and multiple bone lesions. Whenever multiple, fluorodeoxyglucose-avid bone lesions are found, malignancy and metabolic bone disease should both be included in the differential diagnosis. Fluorodeoxyglucose-avid and corticalis-disrupting lytic lesions also occur in benign bone disease. There may be very few similar cases with heterogeneous and widespread bone lesions reported in the literature, but we think our patient's case is particularly remarkable for its detailed imaging and the well-documented course.

Osteolytic lesions: osteitis fibrosa cystica in the setting of severe primary hyperparathyroidism.

A 58-year-old female patient presented with several weeks history of significant bilateral knee pain. Initial knee radiographs demonstrated lucencies of the bony cortex while extensive osteolytic lesions on a routine chest radiograph were suggestive of multiple myeloma or bony metastases. Biochemical investigation revealed primary hyperparathyroidism with renal insufficiency. A parathyroid adenoma was demonstrated on a neck ultrasound and sestamibi scan and subsequently confirmed by histology. We illustrate a case of primary hyperparathyroidism with osteitis fibrosa cystica and brown tumours which were initially mistaken for malignant disease.

A thoracic vertebral brown tumor presenting with paraparesis in a patient with end-stage renal disease.

Vertebral brown tumors are rare, non-neoplastic bone lesions that occur in the setting of hyperparathyroidism. There are differences in the management of them in the literature. Because brown tumors usually resolve after a parathyroidectomy. We present a case of a thoracic vertebral brown tumor with paraparesis.