SEER Inquiry System - Question 20021061 Details

For cases diagnosed prior to 1/1/2010:The patient does not have two different malignancies. Code the Histology field to 9700/3 [mycosis fungoides], the specific type of cutaneous T cell lymphoma. Mycosis fungoides is one of several types of cutaneous T cell lymphoma. Physicians often refer to mycosis fungoides by the "umbrella term" cutaneous T cell lymphoma.

The table indicates that the broad category of "T/NK-cell NHL" (which includes CTCL) and mycosis fungoides are presumably separate primaries because several entities are included in that broad category. In the specific case cited above, one entity (CTCL) within the broad category (T/NK-cell NHL) and mycosis fungoides are not separate primaries.

For cases diagnosed 2010 forward, refer to the Hematopoietic and Lymphoid Neoplasm Case Reportability and Coding Manual and the Hematopoietic Database (Hematopoietic DB) provided by SEER on its website to research your question. If those resources do not adequately address your issue, submit a new question to SINQ.