Neoplasm of uncertain behavior of connective and other soft tissue

This code signifies a tumor originating in connective tissues (e.g., fat, muscle, cartilage, bone, fibrous tissue) or other soft tissues, where the pathologist cannot definitively classify it as benign or malignant based on current microscopic examination. It represents an intermediate category for neoplasms whose biological behavior is uncertain.

Apply this code when pathology reports describe a soft tissue neoplasm as "uncertain behavior," "borderline malignancy," or "indeterminate." Documentation must clearly indicate that the tumor's nature (benign vs. malignant) could not be conclusively determined after thorough histological analysis.

• Do not use this code if the pathology report definitively states benign or malignant; instead, use the appropriate benign or malignant neoplasm code.
• Requires a pathology report confirming "uncertain behavior" for soft tissue.
• Distinguish from "unspecified" neoplasms (e.g., 239.x), which imply insufficient documentation, not an uncertain pathological determination.