ICD-10 Code C49.4 – Malignant neoplasm of connective and soft tissue of abdomen (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C49.4 – Malignant neoplasm of connective and soft tissue of abdomen
What it is
C49.4 identifies a malignant tumor arising in the connective or soft tissues of the abdomen. Use it when the record specifies a primary cancer in abdominal soft tissue rather than a visceral organ.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe an abdominal soft-tissue mass, pain, swelling, or findings from imaging and biopsy confirming malignancy.
When to use this code
Use this code when the provider documents a malignant neoplasm of abdominal connective tissue or soft tissue, including sarcoma-type tumors in that location. It also applies when pathology or imaging localizes the primary tumor to the abdomen and not to an intra-abdominal organ. Check documentation if the site is described only as retroperitoneal, peritoneal, or unspecified.
Do not use for
Do not use C49.4 for malignant neoplasms of digestive organs, peritoneum, or retroperitoneum unless the record clearly states abdominal soft tissue. If the site is unclear, check documentation.
Coding tip
Verify the anatomic site carefully; abdominal soft tissue is not the same as an abdominal organ or retroperitoneal tumor.