"Question ID","Question","Discussion","Answer","Year" "20081044","MP/H Rules/Behavior--Melanoma of Skin: How are histology and behavior coded for a ""malignant melanoma in situ with regression""? See Discussion.","Per the microscopic portion of the path report, there is a zone of regression within the confines of the lesion, such that the possibility of antecedent invasive disease at the site cannot be ruled out with certainty.","

For cases diagnosed 2007 or later:

Code malignant melanoma in situ with regression to 8720/2 [Melanoma in situ].

Code the histology according to the histologic type specified in the pathology report final diagnosis. Code the behavior as specified in the pathology report. Regression does not affect the coding of histology or behavior. See Melanoma Histology Coding rule H5. See 2007 SEER manual instructions for coding behavior, page 84.

","2008"