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A 23-year-old African American man comes to the emergency department due to back and lower extremity pain for 2 days. He has had several similar episodes over the last 15 years that have required hospitalization. His pain is not responsive to over-the-counter analgesics, and review of his prior records shows that he has needed treatment with opioids for adequate pain relief. The patient does not use tobacco, alcohol, or illicit drugs. On physical examination, he has scleral icterus and tenderness over his lower back and long bones of his thighs. Laboratory evaluation shows a hemoglobin level of 6.7 g/dL.
Item 1 of 2
Histopathologic evaluation of this patient's spleen is most likely to reveal which of the following?
This patient with frequent episodes of bony pain likely has sickle cell disease (SCD), an autosomal recessive condition characterized by hemolytic anemia and vaso-occlusion. The hemolytic anemia causes jaundice (due to unconjugated hyperbilirubinemia) and promotes formation of pigmented gallstones. Vaso-occlusion by sickled red blood cells occurs in various tissues, causing hypoxia and acidosis (vaso-occlusive pain episodes). Microvascular occlusion nearly always affects the spleen due to the trapping of sickle cells by the rigid splenic cords; autoinfarction begins in early childhood and can precipitate splenic sequestration crisis in infants. However, repeated infarction eventually leads to significant scarring, fibrosis, and atrophy of the spleen, which would likely be present in this adult patient.
Asplenic patients are more susceptible to infections with encapsulated bacteria (eg, group B Streptococcus, Haemophilus influenzae, Streptococcus pneumoniae, Neisseria meningitidis, Salmonella typhi).
(Choice A) Splenic congestion occurs during a splenic sequestration crisis (marked hemoglobin decrease, rapidly enlarging spleen), which develops due to vaso-occlusion within the cords of Billroth and splenic pooling of erythrocytes. However, repeated infarction leads to functional asplenia and autosplenectomy (splenic atrophy) by late childhood/adolescence.
(Choices B and D) Splenic cyst formation typically occurs due to infection. Splenic infiltration can be seen with metastatic neoplasms but is not a feature of SCD.
(Choice E) The white pulp of the spleen is composed of lymphoid tissue. Lymphoid hyperplasia may represent infection or malignancy.
Educational objective:
Sickle cell disease is characterized by repeated splenic infarctions that ultimately result in splenic atrophy and fibrosis, a process that is typically complete by late childhood/adolescence. After autosplenectomy, patients are predisposed to infections with encapsulated bacterial organisms.