Patients with sickle cell disease (SCD) may experience complications in several abdominal organs as result of vaso-occlusion, hemolysis, or infection—some of them life-threatening. Therefore, clinicians should be aware of SCD-related abdominal manifestations, as an early diagnosis is essential to improve outcomes.

Some complications, such as iron deposition and extramedullary hematopoiesis, may affect multiple organs, while others are organ-specific.

“In the abdomen and pelvis, imaging findings of extramedullary hematopoiesis include a focal soft-tissue mass(es) within solid organs (the liver and spleen are most commonly affected); organ enlargement; or a soft-tissue mass(es) in the perirenal space, omentum, small bowel mesentery, peritoneum, paravertebral region, thorax, or even skin,” Solomon et al explained in RadioGraphics.

The main cause of pain and end organ damage within the abdomen of SCD patients is small vessel vasculopathy. Inflammation and occlusion of the affected vessel lead to ischemic or reperfusion injury, which are responsible for end organ-specific symptoms and imaging findings.

Read more about SCD complications

In addition, iron deposition occurs in SCD due to blood transfusion. Hepatic iron deposition is very common in SCD, affecting most patients (up to 87%). Glandular iron deposition is less common.

“Because high concentrations of iron can be toxic to the organs, especially the liver, detection and grading of iron overload is critical,” Solomon et al wrote. Imaging findings include echogenicity of solid organs (in particular the liver, spleen, and kidneys) and increased organ size and attenuation.

The following sections provide an overview of organ-specific SCD manifestations.

Lungs

Pulmonary complications are a significant cause of morbidity and mortality in patients with SCD. For instance, pulmonary infection and acute chest syndrome (ACS) are leading causes of death in these patients, being responsible for the death of 17% of patients each. ACS can be triggered by infection, pulmonary embolism, and infarction. In severe cases, it can progress to acute respiratory distress syndrome and chronic lung disease.

Patients with SCD are also at increased risk for pulmonary embolism. Additional pulmonary manifestations include pulmonary hypertension, chronic fibrosis, and interstitial lung disease.

Liver and Galbladder

Liver complications of SCD include sickle cell hepatopathy, hepatic sequestration, cholestasis, viral hepatitis, hepatic infarction, abscess, hepatomegaly, cirrhosis, and hepatocellular carcinoma.

Hepatomegaly is very common in SCD, affecting almost two-thirds of patients. It may develop as a consequence of acute or chronic sequestration, iron deposition, infarction, or viral infection. The incidence of hepatitis B and C in patients with SCD is higher than in the general population. Hepatic infarction occurs in approximately one-third of patients.

Sickle cell hepatopathy can co-occur with cholestasis and hepatic sequestration, which are rare but potentially life-threatening conditions. Acute anemia and viral and bacterial infections are risk factors for acute hepatic sequestration. Acute presentations of cholestasis are clinical emergencies.

Black pigment gallstones can be observed in most patients with SCD. They might be an incidental finding or may manifest with abdominal pain from biliary colic, which occurs in about two-thirds of patients, cholecystitis, choledocholithiasis, cholangitis, or gallstone pancreatitis.

Spleen

About 10% of SCD patients older than 10 years have splenomegaly, which can be secondary to vascular congestion, infarction, or abscess. Splenic infarction is a common complication of SCD, whereas splenic abscess is relatively uncommon.

Splenic infarcts may lead to functional asplenia and autosplenectomy, which often occur within the first 18-36 months of life. “Patients with a fully infarcted and calcified spleen are susceptible to gram positive bacteria and may be given prophylactic penicillin,” advised Kinger et al in Current Problems in Diagnostic Radiology. Abscess formation may follow infarction and/or superinfection.

Another relatively uncommon complication of SCD is splenic sequestration, affecting less than 13% of patients. It mainly occurs in children with homozygous HbS and can be triggered by pain crisis, infection, or ACS. About half of children experience recurrent episodes.

Gastrointestinal and Pancreas

Patients with SCD may present with ileus, ischemic enteritis and colitis, infarction, necrosis, and even perforation of the small bowel. Superinfection and perforation of ischemic bowel may cause abscess formation, while chronic ischemia can lead to gastric ulceration and peptic ulcer disease.

Pancreatitis is an uncommon complication of SCD, with the prevalence being similar to that of the general population.

Urinary Tract

Nearly 60% of homozygous HbS patients show renal involvement. “The kidneys are particularly sensitive to microvascular obstruction and ischemia owing to their heavy vascularity and high rate of oxygen consumption,” Solomon et al explained.

Sickle cell nephropathy, renal vein thrombosis, and end-stage renal disease have been reported in patients with SCD. Damage to the renal medulla predisposes to pyelonephritis, cystitis, and renal abscess. Patients with SCD may also present with multifocal bilateral renal cortical infarcts, which may coexist with renal cortical necrosis, renal papillary necrosis, and renal medullary carcinoma.

Genital

SCD is a common cause of priapism with SCD patients having a 30%-40% lifetime risk of developing the condition. Priapism in SCD exhibits some important differences form non-SCD priapism. “While the corpus spongiosum in patients without SCD is typically not involved and the glans remains soft, priapism in SCD is ischemic in cause and demonstrates tricorporal involvement,” highlighted Solomon et al. In addition, almost 25% of men with SCD develop atrophic testes and hypogonadism.

Musculoskeletal

Tissue infarction, splenic dysfunction, and iron deposition in SCD increase the risk of osteomyelitis, which affects 12%-18% of patients. Long bone diaphyseal infections are the most frequent but any bone can be affected.

Additional SCD-related bone manifestations include bone marrow reconversion, intra- and extra-medullary marrow hyperplasia, avascular necrosis, infarction, septic arthritis, osteopenia, and osteoporosis.

Reference

Solomon N, Segaran N, Badawy M, et al. Manifestations of sickle cell disorder at abdominal and pelvic imaging. RadioGraphics. 2022;42(4):1103-1122. doi:10.1148/rg.210154

Kinger NP, Moreno CC, Miller FH, Mittal PK. Abdominal manifestations of sickle cell disease. Curr Probl Diagn Radiol. 2021;50(2):241-251. doi:10.1067/j.cpradiol.2020.05.012