A 54-year-old woman comes to the office due to fatigue. She also notes a tingling sensation in her feet and light-headedness and palpitations during moderate physical activity. The patient has no chronic health conditions and takes no medication regularly. She has never had surgery. The patient eats a balanced diet and does not use tobacco, alcohol, or illicit drugs. Vital signs are within normal limits. Physical examination shows pale conjunctivae and a shiny tongue. Ankle reflexes are decreased bilaterally. Laboratory results are as follows: This patient is at greatest risk for which of the following long-term complications?

Question

A 54-year-old woman comes to the office due to fatigue.  She also notes a tingling sensation in her feet and light-headedness and palpitations during moderate physical activity.  The patient has no chronic health conditions and takes no medication regularly.  She has never had surgery.  The patient eats a balanced diet and does not use tobacco, alcohol, or illicit drugs.  Vital signs are within normal limits.  Physical examination shows pale conjunctivae and a shiny tongue.  Ankle reflexes are decreased bilaterally.  Laboratory results are as follows:  This patient is at greatest risk for which of the following long-term complications?

Quizplus · Accepted Answer

11ec25c8_d437_db8f_bc81_7509c537141e_MD0003_00 This patient's symptomatic macrocytic anemia (light-headedness, palpitations) with glossitis (smooth tongue) and lower extremity neurologic findings (paresthesia, diminished reflexes) suggests vitamin B₁₂ deficiency. Vitamin B₁₂ absorption relies on the salivary glands (R-protein), stomach (intrinsic factor, gastric acid), pancreas (proteases), and ileum (absorption). Although damage to any of these structures can impair uptake, the most common cause of vitamin B₁₂ deficiency is pernicious anemia. Pernicious anemia is marked by antibody-mediated destruction of intrinsic factor, a protein carrier produced by gastric parietal cells and required for vitamin B₁₂ absorption. Antibodies also directly target gastric parietal cells, leading to atrophy of the acid/pepsin-producing parts of the stomach. Over time, the atrophic gastric mucosa undergoes intestinal-type metaplasia, which dramatically increases the risk of gastric cancer. Therefore, patients with pernicious anemia require esophagogastroduodenoscopy at initial diagnosis and with any suspicious symptoms (eg, positive fecal occult blood test, mid-epigastric abdominal pain). (Choice A) Risk of acute myeloid leukemia is increased with certain hematologic malignancies (eg, myelofibrosis). Although myelofibrosis can cause symptomatic anemia, macrocytosis is uncommon and peripheral neuropathy is not generally seen. (Choice B) Aortic aneurysm can be a complication of syphilis. Although tabes dorsalis (a form of neurosyphilis) can be associated with lower extremity paresthesia (posterior column damage), most patients have sensory ataxia and lancinating pains. Macrocytic anemia would be atypical. (Choice C) Cirrhosis is a common complication of chronic hepatitis C virus infection, which may cause symptomatic hemolytic anemia and peripheral neuropathy due to mixed cryoglobulinemia. However, macrocytic anemia would be atypical. In addition, patients with mixed cryoglobulinemia generally have systemic manifestations (eg, weakness, fatigue, arthralgia). (Choice E) Glomerulonephritis is a common consequence of systemic lupus erythematosus (SLE). Although SLE can be associated with anemia and paresthesia (due to peripheral neuropathy), macrocytosis is uncommon and the peripheral neuropathy is usually asymmetric. (Choice F) Risk of T-cell lymphoma is increased with human T-lymphotropic virus type 1. Patients generally develop progressive leg weakness and spasticity with upper motor neuron signs (eg, hyperreflexia, clonus, Babinski reflex). Macrocytic anemia and diminished reflexes are not typically seen. Educational objective: Vitamin B₁₂ deficiency often presents with macrocytic anemia and/or neurologic manifestations (eg, paresthesia, subacute combined degeneration). Most cases are seen in older individuals with pernicious anemia, marked by antibody-mediated destruction of intrinsic factor and gastric parietal cells. Damage to the stomach results in gastric atrophy and increases the risk of gastric cancer.

A 54-Year-Old Woman Comes to the Office Due to Fatigue