Borderline Terms

The lines between benign (non-reportable) and malignant (reportable) diagnoses are graying.

This is a list of terms that sound malignant but are coded as borderline:

• Metastasizing leiomyoma
• T-cell large granular lymphocytic leukemia
• NK-cell large granular lymphocytic leukemia
• Pilocytic astrocytoma
• Superficial well-differentiated liposarcoma
• Well-differentiated liposarcoma of superficial soft tissue

Juvenile melanoma sounds malignant, but is actually a benign neoplasm (behavior code = /0). Note that the term juvenile refers to the cell type, not the age of the patient.

Large granular lymphocytic leukemia is very indolent and extremely common in the population according to the expert hematopathologists on the ICD-O-3 committee.

Pilocytic astrocytoma was downgraded from behavior code /3 to behavior code /1 -- however, for the sake of continuity, pilocytic astrocytoma will continue to be collected in many registries for the next few years.

Well-differentiated liposarcoma is another very indolent tumor.