ICD-10 Code C38.1 – Malignant neoplasm of anterior mediastinum (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C38.1 – Malignant neoplasm of anterior mediastinum
What it is
C38.1 identifies a malignant tumor arising in the anterior mediastinum, the front part of the chest cavity between the lungs. Use it when documentation specifies this location and confirms cancer.
Clinical signs
Clinical features vary; refer to documentation. Patients may have a mediastinal mass on imaging, chest discomfort, cough, or shortness of breath, but the coded diagnosis should be supported by the documented malignant site.
When to use this code
Use C38.1 when the provider documents a primary malignant neoplasm of the anterior mediastinum. It is appropriate for pathology, imaging, or oncology notes that clearly localize the cancer to this region. If the record is nonspecific, check documentation before assigning the code.
Do not use for
Do not use this code for benign mediastinal masses, metastases to the mediastinum, or malignant neoplasms documented in another mediastinal site. If the exact site is unclear, do not guess.
Coding tip
Confirm both malignancy and the anterior mediastinal site in the provider record before coding.