A 70-year-old woman comes to the office due to back pain, fatigue, and inability to carry out her daily work. The pain began 6 months ago and has slowly intensified. The patient had a hip fracture 3 months ago but has no other medical conditions. She is a lifetime nonsmoker and drinks alcohol on social occasions. She currently takes no medications. The patient has no extremity weakness or paresthesia. She has mild constipation; urination is normal. Initial laboratory results are as follows: Dipstick urinalysis is normal.
Which of the following is the best next step in management of this patient?

Question

A 70-year-old woman comes to the office due to back pain, fatigue, and inability to carry out her daily work.  The pain began 6 months ago and has slowly intensified.  The patient had a hip fracture 3 months ago but has no other medical conditions.  She is a lifetime nonsmoker and drinks alcohol on social occasions.  She currently takes no medications.  The patient has no extremity weakness or paresthesia.  She has mild constipation; urination is normal.  Initial laboratory results are as follows:  Dipstick urinalysis is normal.
Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: This patient likely has multiple myeloma (MM), a plasma cell dyscrasia marked by excessive production of monoclonal immunoglobulin. MM commonly presents with bone painand anemia due to bone marrow infiltration with malignant cells; subsequent bone demineralization can lead to hypercalcemia (which can cause constipation). Systemic manifestations (eg, fatigue) are common. Fractures can occur (due to osteolytic lesions), and congestion of the glomerulus with immunglobulins/immunoglobulin fragments results in renal insufficiency. Erythrocyte sedimentation rate (ESR) is often artificially elevated due to increased viscosity of the plasma from paraproteinemia. Urine dipstick testing may show elevated protein, but results are often normal because the protein portion of the urine dipstick primarily detects urinary albumin. Evaluation of MM begins with serum or urine protein electrophoresis. The presence of a monoclonal immunoglobulin spike (M-spike) is highly suggestive of the disease, but confirmation requires the identification of ≥10% abnormal plasma cells on bone marrow biopsy. (Choice A) 1,25-Dihydroxyvitamin D can be produced by tumors (eg, Hodgkin lymphoma), leading to hypercalcemia. However, MM generally causes hypercalcemia due to infiltration of the bone marrow with neoplastic cells and subsequent bone demineralization. Testing 1,25-Dihydroxyvitamin D level is unlikely to identify the underlying diagnosis. (Choice B) c-ANCA is typically elevated in granulomatosis with polyangiitis and microscopic polyangiitis. Although these conditions are associated with increased ESR and renal insufficiency, patients typically upper/lower airway disease and signs of glomerulonephritis on urine testing. (Choice C) Parathyroid hormone-related protein can cause hypercalcemia, but it is usually elevated in the setting of lung cancer (eg, squamous cell carcinoma). This nonsmoker with renal insufficiency and markedly elevated ESR is more likely to have MM than lung cancer. (Choice D) Renal injury in MM is usually due to light-chain nephropathy or hypercalcemia. Kidney biopsy may be useful when the underlying diagnosis is uncertain. Renal ultrasonography is primarily helpful in the setting of suspected renal obstruction, which is unlikely in this case. Educational objective: Multiple myeloma is a plasma cell dyscrasia marked by generation of monoclonal immunoglobulin. Classic features include bone pain, renal insufficiency, hypercalcemia, anemia, and hyperproteinemia. Serum or urine protein electrophoresis is the first diagnostic step, followed by confirmatory bone marrow biopsy (≥10% malignant plasma cells). References: Multiple myeloma: diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/16212152)

A 70-Year-Old Woman Comes to the Office Due to Back