Malignant Neoplasm Coding of the Lymphoid System Test your skills with a new coding question from Clinical Coding Workout every Monday. In ICD-10-CM, malignant neoplasm coding of the lymphoid system (C81–C85), a fifth character of 5 refers to which organs? Lymph nodes of inguinal region and lower limb Lymph nodes of head, face, and neck Lymph nodes of axilla and upper limb Intrapelvic lymph nodesSource: AHIMA Press. Clinical Coding Workout, 2019. https://my.ahima.org/store/product?id=65592. Leave a comment