Guideline Summary: Diagnosis and Management of Left Upper Quadrant Pain with Elevated Red Blood Cell Count

Immediate Diagnostic Imaging

• Contrast‑enhanced CT of the abdomen and pelvis with intravenous contrast should be the first‑line study, providing approximately 69 % sensitivity for acute left‑upper‑quadrant (LUQ) abnormalities and essential for detecting life‑threatening splenic complications in patients with hematologic disorders. American College of Radiology recommendation. 1

Differential Diagnosis of LUQ Pain

• Cardiac etiologies (e.g., angina, pericarditis) must be excluded, as coronary artery disease can present atypically with LUQ pain. American College of Radiology guidance. 1
• Gastric and pancreatic diseases (peptic ulcer disease, gastritis, pancreatitis) are common LUQ pain sources and should be considered early. American College of Radiology guidance. 1
• Renal pathology (pyelonephritis, renal colic) can mimic LUQ pain and requires evaluation. American College of Radiology guidance. 1
• Pulmonary conditions (pneumonia with pleuritic pain) may present as LUQ discomfort and should be ruled out. American College of Radiology guidance. 1

Clinical Assessment

• Physical examination of the LUQ has poor inter‑rater reliability (< 5 % of abdominal pain truly localizes there); therefore imaging is mandatory rather than optional. American College of Radiology recommendation. 1
• Kehr’s sign (referred left‑shoulder pain) is a classic indicator of splenic capsular irritation from infarction, subcapsular hematoma, or impending rupture. American College of Radiology guidance. 2
• Tachycardia or hypotension suggests occult hemorrhage from splenic rupture or sequestration and warrants urgent imaging. American College of Radiology guidance. 2
• Fever mandates prompt imaging to evaluate for splenic abscess, which requires early drainage to prevent rupture and peritonitis. American College of Radiology recommendation. 1

Laboratory Evaluation

• A rapid drop in hemoglobin/hematocrit on CBC indicates splenic sequestration or active bleeding, both life‑threatening emergencies. American College of Radiology recommendation. 3
• Peripheral blood smear should be performed to detect hemolytic disorders (e.g., sickle cell disease, hereditary spherocytosis). American College of Radiology guidance. 3
• Abnormal liver enzymes on comprehensive metabolic panel are significantly associated with portal hypertension as a cause of splenomegaly (P < 0.01). American College of Radiology data. 3
• Thrombocytopenia on platelet count suggests hypersplenism. American College of Radiology guidance. 3

Imaging Recommendations

• Intravenous contrast is indispensable because it visualizes splenic parenchyma, detects infarcts (ultrasound misses ~82 %), characterizes hematomas/abscesses, and identifies vascular lesions such as pseudo‑aneurysms or splenic‑vein thrombosis. American College of Radiology recommendation. 2
• Non‑contrast CT markedly reduces detection of splenic infarcts, small lesions, and vascular abnormalities and should be avoided in the acute setting. American College of Radiology recommendation. 2
• Ultrasound sensitivity for splenic infarction is only ~18 % compared with contrast‑enhanced CT, making it unsuitable as a primary modality. American College of Radiology data. 2
• Ultrasound with Doppler may be used for initial size assessment and serial monitoring in stable patients, but must not replace CT when acute pathology is suspected. American College of Radiology guidance. 2
• MRI (with and without IV contrast) achieves 96–99 % diagnostic accuracy and is preferred for pregnant patients or children when available. American College of Radiology recommendation. 2

Management of Specific Splenic Pathologies

Splenic Infarction

• Obtain transthoracic echocardiography to search for an embolic source (e.g., endocarditis, cardiac thrombus). American College of Radiology recommendation. 2
• Initiate anticoagulation when not contraindicated, following American College of Chest Physicians guidelines. American College of Chest Physicians guideline. 4
• Evaluate for an underlying myeloproliferative neoplasm; if polycythemia vera is confirmed, start cytoreductive therapy to keep hematocrit < 45 % and reduce future thrombotic events. National Comprehensive Cancer Network (NCCN) guideline. 4

Splenic Rupture or Large Hematoma

• Urgent surgical consultation for possible splenectomy or splenic‑artery embolization is required. American College of Radiology recommendation. 2
• Continuous vital‑sign monitoring is essential to detect progression to hemorrhagic shock. American College of Radiology recommendation. 2

Splenic Abscess

• Perform CT‑guided percutaneous drainage as first‑line therapy in hemodynamically stable patients to preserve splenic immune function. American College of Radiology recommendation. 2
• Reserve splenectomy for patients who fail drainage or who are hemodynamically unstable. American College of Radiology recommendation. 2

Isolated Splenomegaly (No Acute Complication)

• Order flow cytometry of peripheral blood when a lymphoproliferative disorder is suspected. American College of Radiology recommendation. 3
• Calculate non‑invasive fibrosis scores (APRI, FIB‑4) to assess for advanced liver fibrosis and portal hypertension as the underlying cause. American College of Radiology recommendation. 3
• Consider bone‑marrow biopsy if a myeloproliferative neoplasm is suspected based on elevated RBC count and splenomegaly. NCCN guideline. 4

Myeloproliferative Neoplasm (MPN) Specific Recommendations

• Start low‑dose aspirin (unless active bleeding is present) to reduce thrombotic risk in confirmed polycythemia vera or essential thrombocythemia. NCCN guideline. 4
• Initiate cytoreductive therapy (hydroxyurea or peginterferon‑α2a) to maintain hematocrit < 45 % in polycythemia vera, thereby decreasing thrombotic events. NCCN guideline. 4
• Assess both thrombosis and bleeding risk before any elective surgical procedure, as patients with MPNs have heightened risk despite optimal management. NCCN guideline. 4

Common Pitfalls to Avoid

• Do not delay imaging based on a “reassuring” physical exam; the poor reliability of LUQ examination, especially in older adults, mandates early contrast‑enhanced CT. American College of Radiology recommendation. 2
• Avoid routine oral contrast, which adds workflow delay without diagnostic benefit and may obscure gastrointestinal pathology. American College of Radiology recommendation. 2
• Absence of fever does not exclude serious splenic pathology; infarction and early abscess formation can be afebrile. American College of Radiology guidance. 5
• Do not overlook an elevated RBC count, as it markedly increases the likelihood of an underlying myeloproliferative disorder with associated thrombotic and splenic complications. NCCN guideline. 4

Clinical Presentation and Urgent Evaluation of Splenic Lesions

Typical Presentation

• Splenic lesions most commonly present with left upper‑quadrant (LUQ) abdominal pain, frequently accompanied by referred left‑shoulder pain (Kehr’s sign); however, a substantial proportion are asymptomatic and are discovered incidentally on imaging performed for other reasons. 6, 7

High‑Risk Populations

Sickle Cell Disease

• In patients with sickle cell disease, the sudden onset of LUQ pain together with an abrupt drop in hematocrit signals splenic sequestration, a condition that markedly increases the risk of circulatory shock and death. 6, 7

Pediatric Patients

• Adolescents – Traumatic splenic injury in adolescents typically manifests as LUQ pain with referred left‑shoulder pain, and may be accompanied by hypovolemic shock or generalized abdominal pain. 8
• Neonates – Splenic injury in neonates can present solely with signs of shock, abdominal rigidity, or altered mental status, making diagnosis especially challenging. 8

Urgent Diagnostic Recommendations

• The combination of fever and LUQ pain mandates immediate imaging to rule out a splenic abscess; early percutaneous or surgical drainage is required to prevent rupture and subsequent peritonitis. 9
• In immunocompromised patients, individuals with known malignancy, or those who have undergone recent surgery or trauma, fever together with LUQ pain strongly suggests the presence of a splenic abscess and should prompt rapid diagnostic work‑up. 9

Important Clinical Pitfalls

• Vague LUQ discomfort in patients known to have splenomegaly should not be dismissed, because capsular expansion heightens the risk of rupture, infarction, and sequestration. 6, 7