ICD-10 Code C58 – Malignant neoplasm of placenta (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C58 – Malignant neoplasm of placenta
What it is
C58 identifies a malignant tumor arising in the placenta. Use it when the provider documents cancer of placental tissue, including placental trophoblastic malignancy.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include abnormal vaginal bleeding, an enlarged uterus, or imaging and pathology results showing placental malignancy.
When to use this code
Use C58 when the diagnosis is confirmed and the record specifically states malignant neoplasm of the placenta. It may appear in pathology reports, operative notes, or oncology documentation. If the chart only suggests a trophoblastic disorder without confirmation, check documentation before coding.
Do not use for
Do not use this code for benign placental conditions, retained placenta, or unspecified gestational trophoblastic disease unless malignancy is documented. Do not assume placental cancer from abnormal pregnancy findings alone.
Coding tip
Code the exact documented placental malignancy and verify whether the provider names a different trophoblastic site or diagnosis.