Differential Diagnosis for Case 25

The patient presents with a complex set of symptoms including fever, right ear discomfort, nausea, vomiting, progressive weakness, neck stiffness, and multiple lytic lesions on skeletal survey. Here is a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Multiple Myeloma: This is the most likely diagnosis given the presence of diffuse osteopenia, multiple lytic lesions in various bones, and the patient's age. Multiple myeloma is a plasma cell disorder characterized by clonal proliferation of malignant plasma cells in the bone marrow, leading to bone destruction and potentially causing the symptoms and findings seen in this patient.

• Other Likely Diagnoses

  • Metastatic Cancer: The presence of multiple lytic lesions could also suggest metastatic cancer, with the primary site potentially being anywhere but commonly seen in breast, lung, or prostate cancers. The absence of an infiltrate on the chest X-ray does not rule out lung cancer, as not all lung cancers present with visible infiltrates.
  • Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with systemic symptoms like fever and weight loss, and bone involvement is possible, although less common than in multiple myeloma.

• Do Not Miss Diagnoses

  • Infections (e.g., Tuberculosis, Fungal Infections): Although the lumbar puncture cultures and gram stain were negative, it's crucial not to miss chronic infections like tuberculosis or fungal infections, which can cause lytic bone lesions and systemic symptoms. These conditions require specific treatments and can be deadly if not addressed.
  • Vascular Events (e.g., Stroke): The progressive weakness and neck stiffness could also suggest a vascular event like a stroke. Although the primary presentation does not strongly suggest this, missing a stroke could have significant consequences.

• Rare Diagnoses

  • Gorlin Syndrome (Nevoid Basal Cell Carcinoma Syndrome): This rare genetic disorder can present with multiple lytic lesions of the bones among other features like basal cell carcinomas and odontogenic keratocysts. It's less likely given the patient's age and presentation but is a consideration in the differential for lytic bone lesions.
  • Langerhans Cell Histiocytosis (LCH): LCH can cause lytic bone lesions and systemic symptoms, although it is more commonly seen in children. Adult presentations are possible and can be more challenging to diagnose.