Differential Diagnosis for Elderly Man with High ESR, Anemia, Deranged RFT, M Spike, and Normal Calcium

• Single Most Likely Diagnosis
  • Multiple Myeloma: Although the presence of an M spike is highly suggestive of multiple myeloma, the normal calcium level is somewhat atypical since hypercalcemia is a common feature. However, not all patients with myeloma have elevated calcium levels, especially in the early stages or in certain variants.
• Other Likely Diagnoses
  • Monoclonal Gammopathy of Undetermined Significance (MGUS): This condition can present with an M spike but typically does not cause significant organ damage. The presence of anemia and deranged renal function tests (RFT) might suggest a more aggressive process, but some cases of MGUS can progress to more severe conditions.
  • Waldenström's Macroglobulinemia: This is a type of non-Hodgkin lymphoma characterized by the production of IgM monoclonal protein. It can cause anemia, elevated ESR, and renal impairment. The normal calcium level does not rule out this diagnosis.
  • Amyloidosis: This condition can cause renal failure, anemia, and an elevated ESR. The presence of an M spike could be related to a plasma cell dyscrasia associated with amyloidosis.
• Do Not Miss Diagnoses
  • Chronic Lymphocytic Leukemia (CLL): Although CLL is more commonly associated with lymphocytosis, some patients can have a monoclonal protein. It's crucial to consider CLL due to its potential for significant morbidity if left untreated.
  • Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with a wide range of symptoms, including anemia, elevated ESR, and renal impairment. A monoclonal spike can be seen in some cases, particularly in lymphomas associated with plasma cell dyscrasias.
• Rare Diagnoses
  • Heavy Chain Disease: This is a rare condition characterized by the production of abnormal heavy chains of immunoglobulins. It can present with anemia, renal impairment, and an elevated ESR.
  • POEMS Syndrome: This rare disorder is characterized by Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, and Skin changes. While it can cause anemia and renal impairment, the full spectrum of symptoms is usually more complex and distinctive.