Differential Diagnosis for 46 yo Female with Elevated Lipoprotein(a) and Bilateral Iliac Crest Pain

Single Most Likely Diagnosis

• Osteonecrosis: Elevated lipoprotein(a) is a known risk factor for osteonecrosis, and bilateral iliac crest pain, especially worse at night, is consistent with this diagnosis. Osteonecrosis can lead to bone pain, particularly in areas with high bone marrow content like the iliac crests.

Other Likely Diagnoses

• Bone Metastases: Although less common, bone metastases from various cancers (e.g., breast, lung, or prostate) can cause bilateral iliac crest pain. The pain typically worsens at night and can be associated with elevated markers like lipoprotein(a) in some cases, though this is more of an indirect association.
• Multiple Myeloma: This is a plasma cell disorder that can cause bone pain, especially in the back, ribs, and hips. Elevated lipoprotein(a) might not be directly related, but the condition can lead to bone lesions and pain, particularly at night.
• Paget's Disease of Bone: A condition characterized by an abnormal breakdown and regrowth of bone tissue, leading to deformity and pain. It can affect any bone but commonly involves the pelvis, which might explain the iliac crest pain.

Do Not Miss Diagnoses

• Osteomyelitis: Although less likely, osteomyelitis (bone infection) can cause severe pain, especially at night, and must be considered due to its potential severity and need for prompt antibiotic treatment. Elevated inflammatory markers would be expected, but lipoprotein(a) levels might not directly correlate.
• Spinal Cord Compression: This is a medical emergency that can cause pain, numbness, and weakness. While the primary complaint is iliac crest pain, any condition causing spinal cord compression (e.g., metastatic cancer, abscess) needs to be ruled out due to its urgency.

Rare Diagnoses

• Langerhans Cell Histiocytosis: A rare disorder in which the body accumulates too many immature Langerhans cells (a type of histiocyte). It can cause bone lesions and pain, among other symptoms.
• Gorham-Stout Disease: A rare condition characterized by the progressive replacement of bone with lymphatic or vascular tissue, leading to bone pain and potentially other systemic symptoms.

Each of these diagnoses has a different level of likelihood based on the provided symptoms and lab findings, but considering them is crucial for comprehensive patient care.