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SEER Inquiry System - Report
Produced: 03/23/2026 2:52 PM
Question 20230050
Inquiry Details
References:
#1: ICD-O-3.2
#2: WHO Class Soft Tissue & Bone, 71-73
Question:
Reportability/Histology--Soft Tissue: Is a diagnosis of Myofibroblastoma with sarcomatous transformation a reportable malignancy? See Discussion.
Discussion:
Patient was diagnosed in September 2022 via excision of a 12 cm pelvic mass with final diagnosis of Myofibroblastoma with sarcomatous transformation.
Diagnosis comment states, “Most of the tumor is composed of conventional features of myofibroblastoma. However, a focal area demonstrates increased cellularity, fascicular growth and increased mitotic activity (up to 11 per 10 hpf), consistent with sarcomatous transformation (morphologically low to intermediate grade).”
Is this sarcomatous transformation describing a malignant transformation from an otherwise benign histology? If so, how should histology be coded in this case?
Answer:
Do not report the case. The histology is 8825/0 based on the example provided and not reportable. Myofibroblastoma with sarcomatous transformation is a rare, benign condition, sometimes referred to as sarcomatous features. A malignant tumor would be referred to as a myofibroblastic sarcoma.
