Malignant neoplasm of myometrium

This code signifies a cancerous tumor originating within the muscular wall of the uterus, known as the myometrium. This malignancy is a type of uterine sarcoma, distinct from the more common endometrial carcinomas.

Apply this code when documentation confirms a primary malignant neoplasm specifically located in the myometrial layer of the uterus. This diagnosis is typically established through biopsy and histopathological examination.

• Differentiate carefully from malignant neoplasms of the endometrium (C54.1), which are much more common.
• Ensure pathology reports explicitly state myometrial involvement as the primary site.
• Code any metastatic sites separately, following the primary diagnosis.