Workup of 13.5 cm Splenomegaly in an Asymptomatic Patient
A spleen measuring 13.5 cm requires systematic evaluation to identify the underlying cause, as this size just exceeds the threshold for clinically significant splenomegaly (>13 cm) and warrants investigation for hematologic malignancies, myeloproliferative disorders, liver disease, and infections. 1, 2
Initial Laboratory Assessment
Obtain a complete blood count with peripheral smear immediately to evaluate for abnormal cells suggestive of hematologic malignancy, as this is the most critical first step. 1
Examine the peripheral smear specifically for:
Add reticulocyte count to assess for hemolysis or bone marrow response 3
Assess liver function as liver disease is one of the three most common causes of splenomegaly in the United States (along with malignancy and infection) 4
Imaging Confirmation
While you likely already have imaging showing the 13.5 cm measurement, confirm proper measurement technique: the spleen should be measured in the coronal plane as vertical length, or calculated by multiplying the number of spleen slices on transverse CT by slice thickness. 2, 3
Risk Stratification Based on Initial Findings
If CBC Shows Cytopenias or Abnormal Cells:
Proceed directly to bone marrow aspiration and biopsy to evaluate for:
- Lymphoproliferative disorders (lymphoma, leukemia) 1
- Myeloproliferative neoplasms (primary myelofibrosis, polycythemia vera, essential thrombocythemia) 1, 3
- Infiltrative processes 1
Order molecular testing for JAK2, CALR, and MPL mutations concurrently with bone marrow biopsy to evaluate for myeloproliferative neoplasms. 1
If CBC is Normal but Hepatomegaly Present:
The combination of hepatosplenomegaly raises concern for hematologic disorders even with normal initial blood counts. 1
- Evaluate for chronic liver disease with hepatitis panel, autoimmune markers, and assessment for cirrhosis 4, 5
- Consider bone marrow biopsy if liver workup is unrevealing, as infiltrative processes can present with organomegaly before peripheral blood changes 1
If CBC and Liver Function are Normal:
Evaluate for infectious causes:
- Infectious mononucleosis (EBV serology) 4
- Travel history for malaria and schistosomiasis (common in tropical regions where up to 80% may have splenomegaly) 4
- HIV testing 4
- Consider other chronic infections based on exposure history 4
If infectious workup is negative, still consider bone marrow biopsy as lymphoproliferative disorders can present with isolated splenomegaly before other manifestations. 1
Critical Differential Diagnoses at 13.5 cm
The size of 13.5 cm is clinically significant because it exceeds the 13 cm threshold established in the Lugano Classification and RECIL 2017 criteria. 2, 3 At this size, the most concerning etiologies are:
- Myeloproliferative neoplasms - particularly if anemia, leukocytosis, or hepatosplenomegaly present 1, 3
- Lymphoproliferative disorders - especially with cytopenias or lymphocytosis 1
- Chronic liver disease with portal hypertension - though splenomegaly is actually an insensitive sign of portal hypertension (only 52% of portal hypertension patients have clinical splenomegaly) 6
Important Caveats
Do not assume the patient is truly asymptomatic - specifically ask about early satiety, left upper quadrant discomfort, constitutional symptoms (fever, night sweats, weight loss), and easy bruising or bleeding 3, 4
Splenomegaly can be present even with normal imaging measurements in infiltrative processes, so clinical context matters 2
The absence of splenomegaly does not rule out portal hypertension, but its presence at 13.5 cm warrants investigation 6
Progressive spleen enlargement over time (if prior imaging available) is a noninvasive predictor of complications and warrants more aggressive workup 7
Counseling Points
Advise the patient to avoid contact sports to decrease risk of splenic rupture, which is one of the most common complications of splenomegaly. 4