A 23-year-old man comes to the emergency department due to severe abdominal pain and fatigue. He has had nausea and vomiting for several hours and is unable to eat. He took ibuprofen but has had no pain relief. The patient has a history of anemia and dark brown urine that has not been evaluated because he tries "to avoid going to the doctor." Review of systems is otherwise negative, and he has no known medical conditions. He emigrated from Scotland during childhood but has not traveled outside the United States since. Temperature is 38.8 C (101.8 F), blood pressure is 120/80 mm Hg, pulse is 102/min, and respirations are 16/min. There is tenderness in the right upper quadrant of the abdomen that is exacerbated by deep inspiration. Splenomegaly and jaundice are present. There are no peritoneal signs. The remainder of the examination is normal. Laboratory results are as follows: Which of the following is the most likely primary cause of this patient's anemia?

Question

A 23-year-old man comes to the emergency department due to severe abdominal pain and fatigue.  He has had nausea and vomiting for several hours and is unable to eat.  He took ibuprofen but has had no pain relief.  The patient has a history of anemia and dark brown urine that has not been evaluated because he tries "to avoid going to the doctor."  Review of systems is otherwise negative, and he has no known medical conditions.  He emigrated from Scotland during childhood but has not traveled outside the United States since.  Temperature is 38.8 C (101.8 F), blood pressure is 120/80 mm Hg, pulse is 102/min, and respirations are 16/min.  There is tenderness in the right upper quadrant of the abdomen that is exacerbated by deep inspiration.  Splenomegaly and jaundice are present.  There are no peritoneal signs.  The remainder of the examination is normal.  Laboratory results are as follows:  Which of the following is the most likely primary cause of this patient's anemia?

Quizplus · Accepted Answer

11ec25c8_d41c_b237_bc81_7df655741277_MD0003_00 This patient has hemolytic anemia, jaundice, and splenomegaly, the classic triad of hereditary spherocytosis (HS). HS is an inherited deficiency of red blood cell (RBC) scaffolding proteins (eg, spectrin, ankyrin). Sphere-shaped RBCs are more fragile and get trapped in splenic fenestrations. The anemia is generally normocytic with associated reticulocytosis in response to hemolysis. Increased mean corpuscular hemoglobin concentration occurs due to membrane loss and RBC dehydration. Chronic hemolysis causes high hemoglobin turnover and excess bilirubin that overwhelms conjugation and elimination from the body. The resulting hyperbilirubinemia manifests as jaundice, dark urine, and pigment (calcium bilirubinate) gallstones. This patient has classic symptoms of acute cholecystitis (fever, right upper quadrant pain, positive Murphy sign, leukocytosis) due to pigment gallstones. In addition to a cholecystectomy for acute gallbladder inflammation, patients need folate supplementation because chronic hemolysis consumes folate. Many patients also require a splenectomy to minimize hemolysis and reduce gallstone risk. (Choice A) Acute gastrointestinal hemorrhage is a rare complication of cholecystitis. This patient's normal blood pressure and prolonged history of dark urine make acute blood loss unlikely. (Choice B) Autoimmune hemolytic anemia can present with normocytic anemia, reticulocytosis, jaundice, and splenomegaly. However, the negative Coombs test in this patient makes an autoimmune process unlikely. (Choices D and F) Leukemia and viral infections can cause anemia by suppressing erythropoiesis. These etiologies are unlikely because this patient's reticulocytosis reflects a robust bone marrow response to anemia. (Choice E) Drug-induced immune hemolytic anemia is a rare complication of ibuprofen and would cause a positive Coombs test. Frequent ibuprofen use can cause gastric ulcers and epigastric pain, but this patient's right upper quadrant abdominal pain and laboratory results suggest acute cholecystitis from HS. (Choice G) Folate deficiency is a complication of chronic hemolytic anemia and can cause a secondary megaloblastic anemia. This patient's mean corpuscular volume is normal. Educational objective: Hereditary spherocytosis is an inherited defect in the red blood cell membrane that presents with hemolytic anemia, jaundice, and splenomegaly. Acute cholecystitis from pigmented gallstones is a common complication. References: Guidelines for the diagnosis and management of hereditary spherocytosis-2011 update. (http://www.ncbi.nlm.nih.gov/pubmed/22055020)

A 23-Year-Old Man Comes to the Emergency Department Due to Severe