Management challenges with brown tumor of primary hyperparathyroidism masked by severe vitamin D deficiency: a case report

Hypovitaminosis D masking hypercalcemia in primary hyperparathyroidism: case report

Hyperparathyroidism (HPTH) is the third most common endocrine disorder. Hypovitaminosis D affects up to 40% of the general population and about a third of hyperparathyroid patients. Such a combination may alter the classic presentation of HPTH. This report presents a premenopausal female with long history of osteoporosis, normocalcemia, and hypovitaminosis D who was initially diagnosed as secondary HPTH. After restoring vitamin D to normal using parenteral loading doses, the patient developed persistent mild to moderate hypercalcemia with persistent parathormone elevation consistent with primary HPTH associated with hypercalciuria and complicated with nephrocalcinosis. Imaging confirmed a left upper parathyroid adenoma and fulfilling several indications for surgery, the patient was operated restoring normocalcemia that was maintained for several years of follow-up. Hypovitaminosis D is common and may mask expected hypercalcemia in patients with primary HPTH, thus delaying diagnosis and proper intervention. Reevaluating patients initially diagnosed as hypovitaminosis D and secondary HPTH may reveal a masked diagnosis of primary hyperparathyroidism.

18F-Sodium Fluoride PET as a Diagnostic Modality for Metabolic, Autoimmune, and Osteogenic Bone Disorders: Cellular Mechanisms and Clinical Applications

In a healthy body, homeostatic actions of osteoclasts and osteoblasts maintain the integrity of the skeletal system. When cellular activities of osteoclasts and osteoblasts become abnormal, pathological bone conditions, such as osteoporosis, can occur. Traditional imaging modalities, such as radiographs, are insensitive to the early cellular changes that precede gross pathological findings, often leading to delayed disease diagnoses and suboptimal therapeutic strategies. ¹⁸F-sodium fluoride (¹⁸F-NaF)-positron emission tomography (PET) is an emerging imaging modality with the potential for early diagnosis and monitoring of bone diseases through the detection of subtle metabolic changes. Specifically, the dissociated ¹⁸F^- is incorporated into hydroxyapatite, and its uptake reflects osteoblastic activity and bone perfusion, allowing for the quantification of bone turnover. While ¹⁸F-NaF-PET has traditionally been used to detect metastatic bone disease, recent literature corroborates the use of ¹⁸F-NaF-PET in benign osseous conditions as well. In this review, we discuss the cellular mechanisms of ¹⁸F-NaF-PET and examine recent findings on its clinical application in diverse metabolic, autoimmune, and osteogenic bone disorders.

Osteitis Fibrosa Cystica Caused by Hyperparathyroidism Shown on 18F-NaF PET/CT

F-NaF PET/CT in hyperparathyroidism and osteitis fibrosa cystica is rarely reported. We report the case of a 16-year-old boy who underwent NaF PET/CT for the evaluation of bilateral bone destruction, which was incidentally noted on an abdominal x-ray. The PET/CT images identified multiple bony abnormalities in the skull, pelvis, and limbs. In addition, a hypodense nodule was found posterior to the inferior pole of the right lobe of thyroid gland. Subsequent Tc-sestamibi imaging showed abnormal uptake in the neck nodule, which was confirmed as parathyroid adenoma by the pathology.

Gnathic Bones and Hyperparathyroidism: A Review on the Metabolic Bony Changes Affecting the Mandible and Maxilla in case of Hyperparathyroidism

Parathyroid glands secrete the parathyroid hormone that plays an essential role in bone remodeling. Excessive production of parathyroid hormone causes a common metabolic bone disorder known as hyperparathyroidism that is classified into primary, secondary, or tertiary. In hyperparathyroidism, the late bony complication is manifested as a giant cell osteolytic lesion called "brown tumor." Primary hyperparathyroidism is usually a sporadic disorder, but in minority of cases it occurs in inherited forms, and one of these forms is the hyperparathyroidism-jaw tumor syndrome, which is characterized by primary hyperparathyroidism and ossifying fibroma in the mandible and/or maxilla.

Evaluation of renal osteodystrophy in the dental clinic by assessment of mandibular and phalangeal cortical indices

OBJECTIVES

Secondary hyperparathyroidism (SHPT) is a disease that affects patients with chronic kidney disease, and is characterized by mineral disturbance and bone loss, known as renal osteodystrophy. The aim of this study was to assess the validity of using intraoral phosphor storage plates to take radiographs of the middle phalanges to evaluate bone loss resulting from SHPT during follow-up of these patients.

METHODS

The sample consisted of 24 patients with chronic kidney disease, 12 with parathyroid hormone (PTH) levels ≥500 pg/ml, and 12 with PTH levels <500 pg/ml, who underwent hemodialysis weekly. For each patient, a panoramic radiograph and digital radiographs of the ring, index, and middle fingers of both hands were taken. The Mandibular Cortical Index (MCI) and the Trabecular Bone Pattern Index (TBP) were applied to the panoramic radiographs, while the Phalangeal Cortical Index (PCI) was applied to the digital radiographs of the phalanges. Three evaluators performed all analyses.

RESULTS

Significant correlations were found between the PTH levels and the MCI (p = 0.023), the PCI (p = 0.039) and the TBP index (p = 0.032). These parameters were also significantly interrelated (MCI × PCI = 0.001; MCI × TBP = 0.004 and PCI × TBP = 0.009). The PCI was shown to have the highest correlation with PTH levels.

CONCLUSION

In patients with chronic renal disease, it is clinically relevant to use panoramic and digital radiographs using intraoral storage plates to assess a number of quantitative parameters that can be linked to PTH levels.

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.

Mandibular Osteitis Fibrosa Cystica as First Sign of Vitamin D Deficiency

Introduction

Brown tumors of hyperparathyroidism are locally destructive bone lesions. They are the late clinical consequence of the disease. They can occur in primary, secondary, and rarely tertiary forms. They affect usually long bones and less frequently those of the maxilla.

Case Report

Our 45-year-old female patient presented with a mandibular tumor next to the first right lower molar. At first, we have chosen tooth extraction and tumor excision. When the histological report showed the giant cell tumor we suspected a metabolic bone disorder. Biochemical tests screened hyperparathyroidism and severe vitamin D deficiency, and parathyroid scintiscan revealed parathyroid adenoma.

Discussion

The association of hyperparathyroidism and vitamin D deficiency leads to diagnostic uncertainty. First, secondary hyperparathyroidism can be due vitamin D deficiency. Second, data available show that vitamin D deficiency is more prevalent in patients with primary hyperparathyroidism than in general population. Hyperparathyroidism management is based on correct and precise diagnosis. Furthermore, the resolution of brown tumors depends on the cure of hyperparathyroidism. In fact, bone lesions should regress after biological tests' normalization.

Conclusion

Clinicians should be aware of such rare and complicated presentation. They must consider the diagnosis of the brown tumor to avoid extensive surgical excision and teeth extractions.