When primary hyperparathyroidism comes as good news.

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Brown tumors are benign, osteoclastic lesions linked to advanced hyperparathyroidism.
• Earlier diagnosis of hyperparathyroidism makes classical manifestations like brown tumors rare.
• Misdiagnosis as primary or metastatic bone cancer is a significant concern.

Purpose of the Study:

• To describe a case of multiple large brown tumors misdiagnosed as osteosarcoma.
• To highlight the diagnostic work-up for challenging giant cell lesions.
• To emphasize the importance of a multidisciplinary approach in diagnosing and treating rare bone disorders.

Main Methods:

• Review of a clinical case involving misdiagnosed brown tumors.
• Endocrine evaluation including parathyroid hormone and calcium level measurements.
• Bone imaging (X-ray, scintiscan, CT) and biopsy with immunostaining (H3G34W, Ki67).

Main Results:

• The case involved multiple large brown tumors initially mistaken for non-treatable osteosarcoma.
• Diagnosis was confirmed through imaging, endocrine tests, and biopsy.
• Successful treatment involved selective parathyroidectomy and denosumab therapy.

Conclusions:

• Brown tumors are unexpected but crucial differential diagnoses in giant cell bone lesions.
• Accurate diagnosis relies on imaging, endocrine assessment, and pathological evaluation.
• Multidisciplinary collaboration is essential for optimal patient outcomes in managing hyperparathyroidism-related bone disease.