Histology (Pre-2007)--Skin: Are "atypical melanocytic hyperplasia" and "severe melanotic dysplasia" synonyms for melanoma in situ?
For tumors diagnosed prior to 2007:
No. SEER determines its reportable list from the ICD-O-3. The above terms are listed as tumor-like lesions and conditions, but are not in situ or malignant.
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.
EOD-Extension--Mycosis Fungoides: Explain the difference between extension codes 25 [% of body surface not stated, no tumors] and 30 [skin involvement, NOS; extent not stated, no tumors. Localized, NOS]?
For cases diagnosed 1998-2003:
For mycosis fungoides: Use code 25 when skin involvement is present but only a general location/site is mentioned (i.e., face, legs, torso, arms).
Use code 30 when there is skin involvement but there is no mention of location/site.