ICD-10 Code C38.8 – Malignant neoplasm of overlapping sites of heart, mediastinum and pleura (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C38.8 – Malignant neoplasm of overlapping sites of heart, mediastinum and pleura
What it is
C38.8 identifies a malignant tumor that involves overlapping sites across the heart, mediastinum, and pleura. Use it when the record shows one cancer spans more than one of these adjacent thoracic sites.
Clinical signs
Clinical features vary; refer to documentation. Thoracic malignancies in these areas may present with chest pain, shortness of breath, cough, or imaging findings showing a mass crossing site boundaries.
When to use this code
Use C38.8 when the provider documents a primary or malignant neoplasm affecting overlapping thoracic structures and does not assign a single more specific site. It is appropriate when pathology, imaging, or operative notes describe extension across the heart, mediastinum, and pleura. Check documentation if the exact origin is unclear.
Do not use for
Do not use this code for benign tumors, metastatic disease to these sites, or cancers limited to one specific thoracic structure. If the documentation names a single site, code that site instead.
Coding tip
Code the overlapping site only when the record clearly supports multi-site involvement and no more specific anatomic code applies.