ICD-10 Code C49.9 – Malignant neoplasm of connective and soft tissue, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C49.9 – Malignant neoplasm of connective and soft tissue, unspecified
What it is
C49.9 identifies a malignant tumor arising in connective or soft tissue when the exact site is not specified. Use it when documentation confirms a soft tissue sarcoma or similar malignancy but does not name the anatomic location.
Clinical signs
Clinical features vary; refer to documentation. These tumors may present as a growing mass, pain, swelling, or limited function depending on location, but diagnosis should be supported by pathology or specialist assessment.
When to use this code
Use C49.9 when the record clearly states malignant neoplasm of connective or soft tissue and no more specific site is available. It also fits when the provider documents a confirmed soft tissue malignancy without laterality or anatomic detail. If the site is specified elsewhere, code that more precise diagnosis instead.
Do not use for
Do not use this code for benign soft tissue tumors, uncertain masses, or metastatic disease to soft tissue. Check documentation if the lesion is described only as a lump, swelling, or suspected cancer.
Coding tip
Query for the exact primary site whenever possible, because C49.9 is an unspecified diagnosis and may not capture a more accurate code.