ICD-10 Code C49.3 – Malignant neoplasm of connective and soft tissue of thorax (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C49.3 – Malignant neoplasm of connective and soft tissue of thorax
What it is
C49.3 identifies a malignant tumor arising in the connective or soft tissues of the thorax. Use it when documentation specifies a primary cancer in chest wall or other thoracic soft tissue structures.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe a palpable thoracic mass, pain, swelling, or imaging evidence of a soft tissue malignancy in the chest region.
When to use this code
Use C49.3 when the provider documents a primary malignant neoplasm of connective or soft tissue located in the thorax. It is appropriate for confirmed sarcoma or other soft tissue cancer of the chest wall when the site is clearly thoracic. If the note only says “chest mass” or “tumor,” check documentation before coding.
Do not use for
Do not use this code for malignant neoplasms of the lung, pleura, or breast, which have different codes. Also avoid it when the lesion is benign, metastatic, or the anatomic site is not clearly thoracic.
Coding tip
Confirm both malignancy and exact thoracic soft tissue site in the provider note before assigning C49.3.