A 57-year-old man comes to the office due to constant middle and low thoracic back pain. The pain started 4 weeks ago and has progressively worsened. It is greatest at night, particularly when he lies down. The patient has had no trauma to the back and has no bowel or bladder symptoms. Review of systems is positive for a 4.5 kg (10 lb) weight loss and fatigue. He has no chronic medical conditions and takes no medications other than a multivitamin. The patient has smoked cigarettes since high school and occasionally drinks beer on weekends. Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, pulse is 80/min, and respirations are 16/min. BMI is 28 kg/m². Examination of the spine shows no focal tenderness, and spinal range of motion is normal. Straight leg raise testing does not elicit pain. Muscle strength and sensation are intact in the lower extremities. Deep tendon reflexes are 2+ bilaterally. Babinski sign is absent. X-ray of the spine shows no abnormalities. Complete blood count and serum creatinine are within normal limits. Which of the following is the most appropriate next step in management?

Question

Quizplus · Accepted Answer

Although back pain is common and often benign, this patient has several features that suggest a more serious pathology. His smoking history, weight loss, and insidious back pain with normal neurologic and x-ray findings raise concern for pancreatic cancer in the tail of the pancreas. Although tumors in the head of the pancreas are frequently associated with obstructive jaundice, steatorrhea, and epigastric pain, tumors in the body or tail of the pancreas may present with progressive, constant back pain that is worse at night when lying supine. The pancreas lies in a retroperitoneal position against the posterior abdominal wall and is innervated by the splanchnic nerves (from T5-T10). Pancreatic tumors often irritate visceral afferent fibers that conduct signals via the splanchnic nerve, leading to referred thoracic back pain. Because this referred pain does not arise from a spinal pathology, spinal/neurologic examination and spinal imaging are generally normal. CT scan of the abdomen, which has a sensitivity >90% for pancreatic lesions, is required. (Choice A) Epidural abscess is associated with insidious back pain, fatigue, and often normal x-ray findings (early in the course of the infection). Most cases arise from hematogenous dissemination of bacteria, which can usually be identified with blood culture. However, most patients have focal back pain on examination, and fever and lower extremity neurologic deficits are common. (Choice B) Bone marrow biopsy is required to diagnose multiple myeloma, which often presents with anemia, hypercalcemia, bone pain, and renal failure. However, radiographic studies usually show lytic bone lesions. lytic bone lesions (Choice D) Physical therapy is sometimes used to treat acute lumbar radiculopathy (in addition to anti-inflammatory medications and early activity). Although this patient's examination and radiographic studies are normal, the presence of significant weight loss, fatigue, and constant, progressive pain that is worse at night necessitates further workup for cancer. (Choice E) Sacroiliac joint imaging can help diagnose ankylosing spondylitis, an inflammatory joint disease that often presents with insidious back pain that is worse at night. However, most cases arise in men age <40, the pain typically improves with activity, and spinal mobility (range of motion) is usually impaired. (Choice F) Upper endoscopy can identify gastric cancer, which is associated with weight loss and smoking. However, most patients have microcytic anemia (due to tumor bleeding into the gastric lumen) and mid-epigastric pain. Back pain is uncommon (because the stomach is intraperitoneal). Educational objective: Pancreatic cancer in the body or tail of the organ may present with constant, progressive back pain that is worse at night and when supine. Because this is a referred pain, back/neurologic examinations and radiographic imaging are generally normal. An abdominal CT scan is usually diagnostic.

A 57-Year-Old Man Comes to the Office Due to Constant