#1: Solid Tumor Rules (2018, 2021)
Source 1: 2021 Solid Tumor Rules
Notes: Cutaneous Melanoma, December 2020 Update
Solid Tumor Rules (2018, 2021)/Histology--Melanoma: In what situation will Rule H6 be used to code the histology to lentigo maligna melanoma? See Discussion.
Rule H6 states: Code 8742/3 (Lentigo maligna melanoma) when the diagnosis is lentigo maligna melanoma with no other histologic types. However, if the diagnosis was strictly lentigo maligna or lentigo maligna melanoma, the first rule that applies is Rule H1 because lentigo maligna melanoma is a single, specific histologic type and Rule H1 states, Code the histology when only one histologic type is identified. Following the current rules, one would never arrive at Rule H6. Should the H Rules be reordered? Or should an example of when one would use Rule H6 be added to clarify when to use this rule?
Solid Tumor rule H6 is the same as MP/H rule H8. We found registrars have problems understanding reportable terminology and the corresponding ICD-O-3 histology code for lentigo maligna melanoma. It is included in H6 to capture cases where the registrar may not stop at H1. We will add another note to H1 instructing users to continue through the rules if the diagnosis is lentigo maligna melanoma.