ICD-10 Code C84.66 – Anaplastic large cell lymphoma, ALK-positive, intrapelvic lymph nodes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C84.66 – Anaplastic large cell lymphoma, ALK-positive, intrapelvic lymph nodes
What it is
This code identifies anaplastic large cell lymphoma that is ALK-positive and involves intrapelvic lymph nodes. Use it when the documentation specifies both the lymphoma subtype and the pelvic nodal site.
Clinical signs
Clinical features vary; refer to documentation. Typical lymphoma findings may include enlarged lymph nodes and systemic “B” symptoms, but the coded diagnosis should be supported by the documented pathology and anatomic site.
When to use this code
Use C84.66 when the provider documents ALK-positive anaplastic large cell lymphoma affecting intrapelvic lymph nodes. Apply it for confirmed primary or involved pelvic nodal disease when the record clearly names this exact site and subtype.
If the note only says anaplastic large cell lymphoma without ALK status or without a pelvic node location, check documentation before assigning this code. The diagnosis should be specific enough to support both the histology and site.
Do not use for
Do not use this code for ALK-negative disease, unspecified anaplastic large cell lymphoma, or lymphoma in other nodal regions. Check documentation if the record does not clearly identify intrapelvic lymph nodes.
Coding tip
Verify both ALK positivity and the intrapelvic lymph node site in the pathology or oncology note before coding C84.66.