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SEER Inquiry System - Report
Produced: 03/24/2026 1:09 AM
Question 20210046
Inquiry Details
References:
#1: WHO Class Skin Tumors, 304-305. 4th edition
#2: ICD-O-3.2
Question:
Reportability--Skin: Is dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous transformation synonymous with dermatofibrosarcoma protuberans, fibrosarcomatous, and therefore reportable for diagnosis year 2021 and forward? See Discussion.
Discussion:
Patient has a 2021 skin excision showing an atypical spindle cell neoplasm, most consistent with dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous transformation.
Per the ICD-O-3.2 Coding Table, DFSP, NOS has a behavior code of /1, and DFSP, fibrosarcomatous has a behavior code of /3. There is no code listed for DFSP with fibrosarcomatous transformation. Transformation is not included as a term that can/cannot be used for the Other Sites Schema, but this type of DFSP is often described as DFSP with fibrosarcomatous transformation. How do we code DFSP when transformation is used to describe fibrosarcomatous?
Answer:
Report DFSP with fibrosarcomatous transformation as it is synonymous with fibrosarcomatous DFSP (8832/3). According to the WHO Classification of Skin Tumors, 4th edition, fibrosarcomatous DFSP is a variant of DFSP and that fibrosarcomatous transformation is seen in approximately 10% of DFSP cases. It is characterized by an often abrupt transition of DFSP.
