ICD-10 Code C83.03 – Small cell B-cell lymphoma, intra-abdominal lymph nodes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C83.03 – Small cell B-cell lymphoma, intra-abdominal lymph nodes
What it is
C83.03 identifies small cell B-cell lymphoma involving intra-abdominal lymph nodes. Use it when the record specifies this lymphoma subtype and the nodal site is within the abdomen.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include enlarged abdominal lymph nodes, abdominal discomfort, or incidental imaging evidence of lymphadenopathy, but the subtype and location must be confirmed.
When to use this code
Use this code when the provider documents small cell B-cell lymphoma affecting intra-abdominal lymph nodes. It also fits pathology, oncology, or discharge notes that clearly identify this exact site and histology. If the site is broader or unspecified, check documentation before coding.
Do not use for
Do not use C83.03 for other B-cell lymphoma subtypes, nodal sites outside the abdomen, or unspecified lymphoma. If the record does not clearly state intra-abdominal lymph node involvement, check documentation.
Coding tip
Code the documented lymphoma subtype and anatomic site exactly as written; if either is missing, query or check documentation.