Differential Diagnosis

The patient's presentation of bone pain, bone edema on MRI, and a history of elevated calcium levels, along with hypertension and thyroid disease, suggests a complex clinical picture. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Bone Marrow Edema Syndrome: This condition is characterized by bone marrow edema seen on MRI, often presenting with bone pain. The transient elevation of calcium could be incidental or related to various factors, including immobilization or mild hyperparathyroidism that was not caught on the single PTH measurement. The normal TSH and PTH levels, along with normal DEXA scans, do not strongly point towards a metabolic bone disease as the primary cause.

• Other Likely Diagnoses

  • Transient Osteoporosis of the Lower Extremities: Although the DEXA scan is normal, this condition can cause bone pain and marrow edema, particularly in the lower extremities. It's more common in middle-aged men.
  • Stress Fractures: Given the bone pain and edema, stress fractures could be a consideration, especially if the patient has been increasing his activity level or has a history of overuse.
  • Hypertrophic Osteoarthropathy (HOA): This condition involves new bone formation and could present with bone pain and edema. However, it's less likely without other systemic symptoms or digital clubbing.

• Do Not Miss Diagnoses

  • Multiple Myeloma: Although the patient's calcium level was only elevated once and other rheumatologic labs were normal, multiple myeloma can present with bone pain, elevated calcium levels, and could potentially cause bone edema. It's crucial to rule out this diagnosis due to its significant implications.
  • Metastatic Disease: Bone metastases can cause pain, edema, and elevated calcium levels. A thorough evaluation for a primary malignancy is essential, especially in a patient of this age group.
  • Paget's Disease of Bone: This condition can cause bone pain, deformity, and elevated alkaline phosphatase levels. Although less likely with a normal DEXA and single elevated calcium, it's a diagnosis that should be considered due to its potential for complications.

• Rare Diagnoses

  • Sarcoidosis: This systemic disease can affect bones, causing pain and edema, and might also lead to hypercalcemia due to increased vitamin D conversion.
  • Gaucher's Disease: A rare genetic disorder that can cause bone pain and marrow infiltration visible on MRI. However, it would be unusual to present for the first time in a 59-year-old without prior symptoms.
  • Chronic Recurrent Multifocal Osteomyelitis (CRMO): A rare condition characterized by recurrent episodes of bone pain and inflammation. It's more common in children but can occur in adults.